diff options
| author | Diego Biurrun <diego@biurrun.de> | 2007-04-07 14:07:33 +0000 |
|---|---|---|
| committer | Diego Biurrun <diego@biurrun.de> | 2007-04-07 14:07:33 +0000 |
| commit | f5bccd85744da7909527c115f339e2dfb21f8dff (patch) | |
| tree | c49d6cc6098e01b005e1690ba34719b8567a8ecb /libavcodec | |
| parent | 414425e0641bb29bd659bfaa31ee1a367214e994 (diff) | |
| download | ffmpeg-f5bccd85744da7909527c115f339e2dfb21f8dff.tar.gz | |
spelling/wording/grammar
Originally committed as revision 8640 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavcodec')
| -rw-r--r-- | libavcodec/avcodec.h | 1213 |
1 files changed, 608 insertions, 605 deletions
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h index 6f04c9b8d4..1b5fec98d8 100644 --- a/libavcodec/avcodec.h +++ b/libavcodec/avcodec.h @@ -23,7 +23,7 @@ /** * @file avcodec.h - * external api header. + * external API header */ @@ -49,14 +49,14 @@ extern "C" { /** * - * if you add a codec id to this list add it so that - * 1. no value of a existing codec id changes (that would break ABI) - * 2. closest to similar codecs + * If you add a codec ID to this list, add it so that + * 1. no value of a existing codec ID changes (that would break ABI), + * 2. it is as close as possible to similar codecs. */ enum CodecID { CODEC_ID_NONE, CODEC_ID_MPEG1VIDEO, - CODEC_ID_MPEG2VIDEO, /* prefered ID for MPEG Video 1 or 2 decoding */ + CODEC_ID_MPEG2VIDEO, /* preferred ID for MPEG-1/2 video decoding */ CODEC_ID_MPEG2VIDEO_XVMC, CODEC_ID_H261, CODEC_ID_H263, @@ -161,7 +161,7 @@ enum CodecID { CODEC_ID_THP, CODEC_ID_SGI, - /* various pcm "codecs" */ + /* various PCM "codecs" */ CODEC_ID_PCM_S16LE= 0x10000, CODEC_ID_PCM_S16BE, CODEC_ID_PCM_U16LE, @@ -180,7 +180,7 @@ enum CodecID { CODEC_ID_PCM_U24BE, CODEC_ID_PCM_S24DAUD, - /* various adpcm codecs */ + /* various ADPCM codecs */ CODEC_ID_ADPCM_IMA_QT= 0x11000, CODEC_ID_ADPCM_IMA_WAV, CODEC_ID_ADPCM_IMA_DK3, @@ -215,7 +215,7 @@ enum CodecID { CODEC_ID_SOL_DPCM, CODEC_ID_MP2= 0x15000, - CODEC_ID_MP3, /* prefered ID for MPEG Audio layer 1, 2 or3 decoding */ + CODEC_ID_MP3, /* preferred ID for decoding MPEG audio layer 1, 2 or 3 */ CODEC_ID_AAC, #if LIBAVCODEC_VERSION_INT < ((52<<16)+(0<<8)+0) CODEC_ID_MPEG4AAC, @@ -237,7 +237,7 @@ enum CodecID { CODEC_ID_SHORTEN, CODEC_ID_ALAC, CODEC_ID_WESTWOOD_SND1, - CODEC_ID_GSM, /* As in Berlin toast format */ + CODEC_ID_GSM, /* as in Berlin toast format */ CODEC_ID_QDM2, CODEC_ID_COOK, CODEC_ID_TRUESPEECH, @@ -249,18 +249,18 @@ enum CodecID { CODEC_ID_IMC, CODEC_ID_MUSEPACK7, CODEC_ID_MLP, - CODEC_ID_GSM_MS, /* As found in WAV */ + CODEC_ID_GSM_MS, /* as found in WAV */ /* subtitle codecs */ CODEC_ID_DVD_SUBTITLE= 0x17000, CODEC_ID_DVB_SUBTITLE, - CODEC_ID_MPEG2TS= 0x20000, /* _FAKE_ codec to indicate a raw MPEG2 transport - stream (only used by libavformat) */ + CODEC_ID_MPEG2TS= 0x20000, /* _FAKE_ codec to indicate a raw MPEG-2 TS + * stream (only used by libavformat) */ }; #if LIBAVCODEC_VERSION_INT < ((52<<16)+(0<<8)+0) -/* CODEC_ID_MP3LAME is absolete */ +/* CODEC_ID_MP3LAME is obsolete */ #define CODEC_ID_MP3LAME CODEC_ID_MP3 #define CODEC_ID_MPEG4AAC CODEC_ID_AAC #endif @@ -274,8 +274,8 @@ enum CodecType { CODEC_TYPE_NB }; -/* currently unused, may be used if 24/32 bits samples ever supported */ -/* all in native endian */ +/* Currently unused, may be used if 24/32 bits samples are ever supported. */ +/* all in native-endian format */ enum SampleFormat { SAMPLE_FMT_NONE = -1, SAMPLE_FMT_U8, ///< unsigned 8 bits @@ -290,16 +290,16 @@ enum SampleFormat { /** * Required number of additionally allocated bytes at the end of the input bitstream for decoding. - * this is mainly needed because some optimized bitstream readers read - * 32 or 64 bit at once and could read over the end<br> - * Note, if the first 23 bits of the additional bytes are not 0 then damaged - * MPEG bitstreams could cause overread and segfault + * This is mainly needed because some optimized bitstream readers read + * 32 or 64 bit at once and could read over the end.<br> + * Note: If the first 23 bits of the additional bytes are not 0, then damaged + * MPEG bitstreams could cause overread and segfault. */ #define FF_INPUT_BUFFER_PADDING_SIZE 8 /** - * minimum encoding buffer size. - * used to avoid some checks during header writing + * minimum encoding buffer size + * Used to avoid some checks during header writing. */ #define FF_MIN_BUFFER_SIZE 16384 @@ -317,7 +317,8 @@ enum Motion_Est_ID { }; enum AVDiscard{ -//we leave some space between them for extensions (drop some keyframes for intra only or drop just some bidir frames) + /* We leave some space between them for extensions (drop some + * keyframes for intra-only or drop just some bidir frames). */ AVDISCARD_NONE =-16, ///< discard nothing AVDISCARD_DEFAULT= 0, ///< discard useless packets like 0 size packets in avi AVDISCARD_NONREF = 8, ///< discard all non reference @@ -329,73 +330,74 @@ enum AVDiscard{ typedef struct RcOverride{ int start_frame; int end_frame; - int qscale; // if this is 0 then quality_factor will be used instead + int qscale; // If this is 0 then quality_factor will be used instead. float quality_factor; } RcOverride; #define FF_MAX_B_FRAMES 16 /* encoding support - these flags can be passed in AVCodecContext.flags before initing - Note: not everything is supported yet. + These flags can be passed in AVCodecContext.flags before initialization. + Note: Not everything is supported yet. */ -#define CODEC_FLAG_QSCALE 0x0002 ///< use fixed qscale -#define CODEC_FLAG_4MV 0x0004 ///< 4 MV per MB allowed / Advanced prediction for H263 -#define CODEC_FLAG_QPEL 0x0010 ///< use qpel MC -#define CODEC_FLAG_GMC 0x0020 ///< use GMC -#define CODEC_FLAG_MV0 0x0040 ///< always try a MB with MV=<0,0> -#define CODEC_FLAG_PART 0x0080 ///< use data partitioning -/* parent program guarantees that the input for b-frame containing streams is not written to - for at least s->max_b_frames+1 frames, if this is not set than the input will be copied */ +#define CODEC_FLAG_QSCALE 0x0002 ///< Use fixed qscale. +#define CODEC_FLAG_4MV 0x0004 ///< 4 MV per MB allowed / advanced prediction for H.263. +#define CODEC_FLAG_QPEL 0x0010 ///< Use qpel MC. +#define CODEC_FLAG_GMC 0x0020 ///< Use GMC. +#define CODEC_FLAG_MV0 0x0040 ///< Always try a MB with MV=<0,0>. +#define CODEC_FLAG_PART 0x0080 ///< Use data partitioning. +/* The parent program guarantees that the input for B-frames containing + * streams is not written to for at least s->max_b_frames+1 frames, if + * this is not set the input will be copied. */ #define CODEC_FLAG_INPUT_PRESERVED 0x0100 -#define CODEC_FLAG_PASS1 0x0200 ///< use internal 2pass ratecontrol in first pass mode -#define CODEC_FLAG_PASS2 0x0400 ///< use internal 2pass ratecontrol in second pass mode -#define CODEC_FLAG_EXTERN_HUFF 0x1000 ///< use external huffman table (for mjpeg) -#define CODEC_FLAG_GRAY 0x2000 ///< only decode/encode grayscale -#define CODEC_FLAG_EMU_EDGE 0x4000///< don't draw edges -#define CODEC_FLAG_PSNR 0x8000 ///< error[?] variables will be set during encoding -#define CODEC_FLAG_TRUNCATED 0x00010000 /** input bitstream might be truncated at a random location instead - of only at frame boundaries */ -#define CODEC_FLAG_NORMALIZE_AQP 0x00020000 ///< normalize adaptive quantization -#define CODEC_FLAG_INTERLACED_DCT 0x00040000 ///< use interlaced dct -#define CODEC_FLAG_LOW_DELAY 0x00080000 ///< force low delay -#define CODEC_FLAG_ALT_SCAN 0x00100000 ///< use alternate scan -#define CODEC_FLAG_TRELLIS_QUANT 0x00200000 ///< use trellis quantization -#define CODEC_FLAG_GLOBAL_HEADER 0x00400000 ///< place global headers in extradata instead of every keyframe -#define CODEC_FLAG_BITEXACT 0x00800000 ///< use only bitexact stuff (except (i)dct) +#define CODEC_FLAG_PASS1 0x0200 ///< Use internal 2pass ratecontrol in first pass mode. +#define CODEC_FLAG_PASS2 0x0400 ///< Use internal 2pass ratecontrol in second pass mode. +#define CODEC_FLAG_EXTERN_HUFF 0x1000 ///< Use external Huffman table (for MJPEG). +#define CODEC_FLAG_GRAY 0x2000 ///< Only decode/encode grayscale. +#define CODEC_FLAG_EMU_EDGE 0x4000///< Don't draw edges. +#define CODEC_FLAG_PSNR 0x8000 ///< error[?] variables will be set during encoding. +#define CODEC_FLAG_TRUNCATED 0x00010000 /** Input bitstream might be truncated at a random location instead + of only at frame boundaries. */ +#define CODEC_FLAG_NORMALIZE_AQP 0x00020000 ///< Normalize adaptive quantization. +#define CODEC_FLAG_INTERLACED_DCT 0x00040000 ///< Use interlaced DCT. +#define CODEC_FLAG_LOW_DELAY 0x00080000 ///< Force low delay. +#define CODEC_FLAG_ALT_SCAN 0x00100000 ///< Use alternate scan. +#define CODEC_FLAG_TRELLIS_QUANT 0x00200000 ///< Use trellis quantization. +#define CODEC_FLAG_GLOBAL_HEADER 0x00400000 ///< Place global headers in extradata instead of every keyframe. +#define CODEC_FLAG_BITEXACT 0x00800000 ///< Use only bitexact stuff (except (I)DCT). /* Fx : Flag for h263+ extra options */ #if LIBAVCODEC_VERSION_INT < ((52<<16)+(0<<8)+0) -#define CODEC_FLAG_H263P_AIC 0x01000000 ///< H263 Advanced intra coding / MPEG4 AC prediction (remove this) +#define CODEC_FLAG_H263P_AIC 0x01000000 ///< H.263 advanced intra coding / MPEG-4 AC prediction (remove this) #endif -#define CODEC_FLAG_AC_PRED 0x01000000 ///< H263 Advanced intra coding / MPEG4 AC prediction -#define CODEC_FLAG_H263P_UMV 0x02000000 ///< Unlimited motion vector -#define CODEC_FLAG_CBP_RD 0x04000000 ///< use rate distortion optimization for cbp -#define CODEC_FLAG_QP_RD 0x08000000 ///< use rate distortion optimization for qp selectioon -#define CODEC_FLAG_H263P_AIV 0x00000008 ///< H263 Alternative inter vlc +#define CODEC_FLAG_AC_PRED 0x01000000 ///< H.263 advanced intra coding / MPEG-4 AC prediction +#define CODEC_FLAG_H263P_UMV 0x02000000 ///< unlimited motion vector +#define CODEC_FLAG_CBP_RD 0x04000000 ///< Use rate distortion optimization for cbp. +#define CODEC_FLAG_QP_RD 0x08000000 ///< Use rate distortion optimization for qp selectioon. +#define CODEC_FLAG_H263P_AIV 0x00000008 ///< H.263 alternative inter VLC #define CODEC_FLAG_OBMC 0x00000001 ///< OBMC #define CODEC_FLAG_LOOP_FILTER 0x00000800 ///< loop filter #define CODEC_FLAG_H263P_SLICE_STRUCT 0x10000000 #define CODEC_FLAG_INTERLACED_ME 0x20000000 ///< interlaced motion estimation -#define CODEC_FLAG_SVCD_SCAN_OFFSET 0x40000000 ///< will reserve space for SVCD scan offset user data +#define CODEC_FLAG_SVCD_SCAN_OFFSET 0x40000000 ///< Will reserve space for SVCD scan offset user data. #define CODEC_FLAG_CLOSED_GOP ((int)0x80000000) -#define CODEC_FLAG2_FAST 0x00000001 ///< allow non spec compliant speedup tricks -#define CODEC_FLAG2_STRICT_GOP 0x00000002 ///< strictly enforce GOP size -#define CODEC_FLAG2_NO_OUTPUT 0x00000004 ///< skip bitstream encoding -#define CODEC_FLAG2_LOCAL_HEADER 0x00000008 ///< place global headers at every keyframe instead of in extradata -#define CODEC_FLAG2_BPYRAMID 0x00000010 ///< H.264 allow b-frames to be used as references -#define CODEC_FLAG2_WPRED 0x00000020 ///< H.264 weighted biprediction for b-frames +#define CODEC_FLAG2_FAST 0x00000001 ///< Allow non spec compliant speedup tricks. +#define CODEC_FLAG2_STRICT_GOP 0x00000002 ///< Strictly enforce GOP size. +#define CODEC_FLAG2_NO_OUTPUT 0x00000004 ///< Skip bitstream encoding. +#define CODEC_FLAG2_LOCAL_HEADER 0x00000008 ///< Place global headers at every keyframe instead of in extradata. +#define CODEC_FLAG2_BPYRAMID 0x00000010 ///< H.264 allow B-frames to be used as references. +#define CODEC_FLAG2_WPRED 0x00000020 ///< H.264 weighted biprediction for B-frames #define CODEC_FLAG2_MIXED_REFS 0x00000040 ///< H.264 one reference per partition, as opposed to one reference per macroblock #define CODEC_FLAG2_8X8DCT 0x00000080 ///< H.264 high profile 8x8 transform #define CODEC_FLAG2_FASTPSKIP 0x00000100 ///< H.264 fast pskip #define CODEC_FLAG2_AUD 0x00000200 ///< H.264 access unit delimiters -#define CODEC_FLAG2_BRDO 0x00000400 ///< b-frame rate-distortion optimization -#define CODEC_FLAG2_INTRA_VLC 0x00000800 ///< use MPEG-2 intra VLC table -#define CODEC_FLAG2_MEMC_ONLY 0x00001000 ///< only do ME/MC (I frames -> ref, P frame -> ME+MC) -#define CODEC_FLAG2_DROP_FRAME_TIMECODE 0x00002000 ///< timecode is in drop frame format -#define CODEC_FLAG2_SKIP_RD 0x00004000 ///< RD optimal MB level residual skiping -#define CODEC_FLAG2_CHUNKS 0x00008000 ///< input bitstream might be truncated at a packet boundaries instead of only at frame boundaries -#define CODEC_FLAG2_NON_LINEAR_QUANT 0x00010000 ///< use MPEG-2 non linear quantizer +#define CODEC_FLAG2_BRDO 0x00000400 ///< B-frame rate-distortion optimization +#define CODEC_FLAG2_INTRA_VLC 0x00000800 ///< Use MPEG-2 intra VLC table. +#define CODEC_FLAG2_MEMC_ONLY 0x00001000 ///< Only do ME/MC (I frames -> ref, P frame -> ME+MC). +#define CODEC_FLAG2_DROP_FRAME_TIMECODE 0x00002000 ///< timecode is in drop frame format. +#define CODEC_FLAG2_SKIP_RD 0x00004000 ///< RD optimal MB level residual skipping +#define CODEC_FLAG2_CHUNKS 0x00008000 ///< Input bitstream might be truncated at a packet boundaries instead of only at frame boundaries. +#define CODEC_FLAG2_NON_LINEAR_QUANT 0x00010000 ///< Use MPEG-2 nonlinear quantizer. /* Unsupported options : * Syntax Arithmetic coding (SAC) @@ -404,21 +406,20 @@ typedef struct RcOverride{ /* /Fx */ /* codec capabilities */ -#define CODEC_CAP_DRAW_HORIZ_BAND 0x0001 ///< decoder can use draw_horiz_band callback +#define CODEC_CAP_DRAW_HORIZ_BAND 0x0001 ///< Decoder can use draw_horiz_band callback. /** * Codec uses get_buffer() for allocating buffers. * direct rendering method 1 */ #define CODEC_CAP_DR1 0x0002 -/* if 'parse_only' field is true, then avcodec_parse_frame() can be - used */ +/* If 'parse_only' field is true, then avcodec_parse_frame() can be used. */ #define CODEC_CAP_PARSE_ONLY 0x0004 #define CODEC_CAP_TRUNCATED 0x0008 -/* codec can export data for HW decoding (XvMC) */ +/* Codec can export data for HW decoding (XvMC). */ #define CODEC_CAP_HWACCEL 0x0010 /** - * codec has a non zero delay and needs to be feeded with NULL at the end to get the delayed data. - * if this is not set, the codec is guaranteed to never be feeded with NULL data + * Codec has a nonzero delay and needs to be fed with NULL at the end to get the delayed data. + * If this is not set, the codec is guaranteed to never be fed with NULL data. */ #define CODEC_CAP_DELAY 0x0020 /** @@ -427,10 +428,10 @@ typedef struct RcOverride{ */ #define CODEC_CAP_SMALL_LAST_FRAME 0x0040 -//the following defines may change, don't expect compatibility if you use them +//The following defines may change, don't expect compatibility if you use them. #define MB_TYPE_INTRA4x4 0x0001 -#define MB_TYPE_INTRA16x16 0x0002 //FIXME h264 specific -#define MB_TYPE_INTRA_PCM 0x0004 //FIXME h264 specific +#define MB_TYPE_INTRA16x16 0x0002 //FIXME H.264-specific +#define MB_TYPE_INTRA_PCM 0x0004 //FIXME H.264-specific #define MB_TYPE_16x16 0x0008 #define MB_TYPE_16x8 0x0010 #define MB_TYPE_8x16 0x0020 @@ -453,28 +454,29 @@ typedef struct RcOverride{ /** * Pan Scan area. - * this specifies the area which should be displayed. Note there may be multiple such areas for one frame + * This specifies the area which should be displayed. + * Note there may be multiple such areas for one frame. */ typedef struct AVPanScan{ /** - * id. - * - encoding: set by user. - * - decoding: set by lavc + * id + * - encoding: Set by user. + * - decoding: Set by libavcodec. */ int id; /** * width and height in 1/16 pel - * - encoding: set by user. - * - decoding: set by lavc + * - encoding: Set by user. + * - decoding: Set by libavcodec. */ int width; int height; /** - * position of the top left corner in 1/16 pel for up to 3 fields/frames. - * - encoding: set by user. - * - decoding: set by lavc + * position of the top left corner in 1/16 pel for up to 3 fields/frames + * - encoding: Set by user. + * - decoding: Set by libavcodec. */ int16_t position[3][2]; }AVPanScan; @@ -482,99 +484,99 @@ typedef struct AVPanScan{ #define FF_COMMON_FRAME \ /**\ * pointer to the picture planes.\ - * this might be different from the first allocated byte\ + * This might be different from the first allocated byte\ * - encoding: \ * - decoding: \ */\ uint8_t *data[4];\ int linesize[4];\ /**\ - * pointer to the first allocated byte of the picture. can be used in get_buffer/release_buffer\ - * this isn't used by lavc unless the default get/release_buffer() is used\ + * pointer to the first allocated byte of the picture. Can be used in get_buffer/release_buffer.\ + * This isn't used by libavcodec unless the default get/release_buffer() is used.\ * - encoding: \ * - decoding: \ */\ uint8_t *base[4];\ /**\ * 1 -> keyframe, 0-> not\ - * - encoding: set by lavc\ - * - decoding: set by lavc\ + * - encoding: Set by libavcodec.\ + * - decoding: Set by libavcodec.\ */\ int key_frame;\ \ /**\ - * picture type of the frame, see ?_TYPE below.\ - * - encoding: set by lavc for coded_picture (and set by user for input)\ - * - decoding: set by lavc\ + * Picture type of the frame, see ?_TYPE below.\ + * - encoding: Set by libavcodec. for coded_picture (and set by user for input).\ + * - decoding: Set by libavcodec.\ */\ int pict_type;\ \ /**\ * presentation timestamp in time_base units (time when frame should be shown to user)\ - * if AV_NOPTS_VALUE then frame_rate = 1/time_base will be assumed\ - * - encoding: MUST be set by user\ - * - decoding: set by lavc\ + * If AV_NOPTS_VALUE then frame_rate = 1/time_base will be assumed.\ + * - encoding: MUST be set by user.\ + * - decoding: Set by libavcodec.\ */\ int64_t pts;\ \ /**\ - * picture number in bitstream order.\ + * picture number in bitstream order\ * - encoding: set by\ - * - decoding: set by lavc\ + * - decoding: Set by libavcodec.\ */\ int coded_picture_number;\ /**\ - * picture number in display order.\ + * picture number in display order\ * - encoding: set by\ - * - decoding: set by lavc\ + * - decoding: Set by libavcodec.\ */\ int display_picture_number;\ \ /**\ * quality (between 1 (good) and FF_LAMBDA_MAX (bad)) \ - * - encoding: set by lavc for coded_picture (and set by user for input)\ - * - decoding: set by lavc\ + * - encoding: Set by libavcodec. for coded_picture (and set by user for input).\ + * - decoding: Set by libavcodec.\ */\ int quality; \ \ /**\ * buffer age (1->was last buffer and dint change, 2->..., ...).\ - * set to INT_MAX if the buffer has not been used yet \ + * Set to INT_MAX if the buffer has not been used yet.\ * - encoding: unused\ - * - decoding: MUST be set by get_buffer()\ + * - decoding: MUST be set by get_buffer().\ */\ int age;\ \ /**\ * is this picture used as reference\ * - encoding: unused\ - * - decoding: set by lavc (before get_buffer() call))\ + * - decoding: Set by libavcodec. (before get_buffer() call)).\ */\ int reference;\ \ /**\ * QP table\ * - encoding: unused\ - * - decoding: set by lavc\ + * - decoding: Set by libavcodec.\ */\ int8_t *qscale_table;\ /**\ * QP store stride\ * - encoding: unused\ - * - decoding: set by lavc\ + * - decoding: Set by libavcodec.\ */\ int qstride;\ \ /**\ - * mbskip_table[mb]>=1 if MB didnt change\ + * mbskip_table[mb]>=1 if MB didn't change\ * stride= mb_width = (width+15)>>4\ * - encoding: unused\ - * - decoding: set by lavc\ + * - decoding: Set by libavcodec.\ */\ uint8_t *mbskip_table;\ \ /**\ - * Motion vector table.\ + * motion vector table\ * @code\ * example:\ * int mv_sample_log2= 4 - motion_subsample_log2;\ @@ -582,16 +584,16 @@ typedef struct AVPanScan{ * int mv_stride= (mb_width << mv_sample_log2) + 1;\ * motion_val[direction][x + y*mv_stride][0->mv_x, 1->mv_y];\ * @endcode\ - * - encoding: set by user\ - * - decoding: set by lavc\ + * - encoding: Set by user.\ + * - decoding: Set by libavcodec.\ */\ int16_t (*motion_val[2])[2];\ \ /**\ - * Macroblock type table\ + * macroblock type table\ * mb_type_base + mb_width + 2\ - * - encoding: set by user\ - * - decoding: set by lavc\ + * - encoding: Set by user.\ + * - decoding: Set by libavcodec.\ */\ uint32_t *mb_type;\ \ @@ -599,37 +601,37 @@ typedef struct AVPanScan{ * log2 of the size of the block which a single vector in motion_val represents: \ * (4->16x16, 3->8x8, 2-> 4x4, 1-> 2x2)\ * - encoding: unused\ - * - decoding: set by lavc\ + * - decoding: Set by libavcodec.\ */\ uint8_t motion_subsample_log2;\ \ /**\ * for some private data of the user\ * - encoding: unused\ - * - decoding: set by user\ + * - decoding: Set by user.\ */\ void *opaque;\ \ /**\ * error\ - * - encoding: set by lavc if flags&CODEC_FLAG_PSNR\ + * - encoding: Set by libavcodec. if flags&CODEC_FLAG_PSNR.\ * - decoding: unused\ */\ uint64_t error[4];\ \ /**\ - * type of the buffer (to keep track of who has to dealloc data[*])\ - * - encoding: set by the one who allocs it\ - * - decoding: set by the one who allocs it\ - * Note: user allocated (direct rendering) & internal buffers can not coexist currently\ + * type of the buffer (to keep track of who has to deallocate data[*])\ + * - encoding: Set by the one who allocates it.\ + * - decoding: Set by the one who allocates it.\ + * Note: User allocated (direct rendering) & internal buffers cannot coexist currently.\ */\ int type;\ \ /**\ - * when decoding, this signal how much the picture must be delayed.\ + * When decoding, this signals how much the picture must be delayed.\ * extra_delay = repeat_pict / (2*fps)\ * - encoding: unused\ - * - decoding: set by lavc\ + * - decoding: Set by libavcodec.\ */\ int repeat_pict;\ \ @@ -640,50 +642,50 @@ typedef struct AVPanScan{ \ /**\ * The content of the picture is interlaced.\ - * - encoding: set by user\ - * - decoding: set by lavc (default 0)\ + * - encoding: Set by user.\ + * - decoding: Set by libavcodec. (default 0)\ */\ int interlaced_frame;\ \ /**\ - * if the content is interlaced, is top field displayed first.\ - * - encoding: set by user\ - * - decoding: set by lavc\ + * If the content is interlaced, is top field displayed first.\ + * - encoding: Set by user.\ + * - decoding: Set by libavcodec.\ */\ int top_field_first;\ \ /**\ * Pan scan.\ - * - encoding: set by user\ - * - decoding: set by lavc\ + * - encoding: Set by user.\ + * - decoding: Set by libavcodec.\ */\ AVPanScan *pan_scan;\ \ /**\ - * tell user application that palette has changed from previous frame.\ + * Tell user application that palette has changed from previous frame.\ * - encoding: ??? (no palette-enabled encoder yet)\ - * - decoding: set by lavc (default 0)\ + * - decoding: Set by libavcodec. (default 0).\ */\ int palette_has_changed;\ \ /**\ - * Codec suggestion on buffer type if != 0\ + * codec suggestion on buffer type if != 0\ * - encoding: unused\ - * - decoding: set by lavc (before get_buffer() call))\ + * - decoding: Set by libavcodec. (before get_buffer() call)).\ */\ int buffer_hints;\ \ /**\ - * DCT coeffitients\ + * DCT coefficients\ * - encoding: unused\ - * - decoding: set by lavc\ + * - decoding: Set by libavcodec.\ */\ short *dct_coeff;\ \ /**\ - * Motion referece frame index\ - * - encoding: set by user\ - * - decoding: set by lavc\ + * motion referece frame index\ + * - encoding: Set by user.\ + * - decoding: Set by libavcodec.\ */\ int8_t *ref_index[2]; @@ -692,9 +694,9 @@ typedef struct AVPanScan{ #define FF_QSCALE_TYPE_H264 2 #define FF_BUFFER_TYPE_INTERNAL 1 -#define FF_BUFFER_TYPE_USER 2 ///< Direct rendering buffers (image is (de)allocated by user) -#define FF_BUFFER_TYPE_SHARED 4 ///< buffer from somewhere else, don't dealloc image (data/base), all other tables are not shared -#define FF_BUFFER_TYPE_COPY 8 ///< just a (modified) copy of some other buffer, don't dealloc anything +#define FF_BUFFER_TYPE_USER 2 ///< direct rendering buffers (image is (de)allocated by user) +#define FF_BUFFER_TYPE_SHARED 4 ///< Buffer from somewhere else; don't deallocate image (data/base), all other tables are not shared. +#define FF_BUFFER_TYPE_COPY 8 ///< Just a (modified) copy of some other buffer, don't deallocate anything. #define FF_I_TYPE 1 // Intra @@ -704,10 +706,10 @@ typedef struct AVPanScan{ #define FF_SI_TYPE 5 #define FF_SP_TYPE 6 -#define FF_BUFFER_HINTS_VALID 0x01 // Buffer hints value is meaningful (if 0 ignore) -#define FF_BUFFER_HINTS_READABLE 0x02 // Codec will read from buffer -#define FF_BUFFER_HINTS_PRESERVE 0x04 // User must not alter buffer content -#define FF_BUFFER_HINTS_REUSABLE 0x08 // Codec will reuse the buffer (update) +#define FF_BUFFER_HINTS_VALID 0x01 // Buffer hints value is meaningful (if 0 ignore). +#define FF_BUFFER_HINTS_READABLE 0x02 // Codec will read from buffer. +#define FF_BUFFER_HINTS_PRESERVE 0x04 // User must not alter buffer content. +#define FF_BUFFER_HINTS_REUSABLE 0x08 // Codec will reuse the buffer (update). /** * Audio Video Frame. @@ -719,48 +721,48 @@ typedef struct AVFrame { #define DEFAULT_FRAME_RATE_BASE 1001000 /** - * main external api structure. + * main external API structure */ typedef struct AVCodecContext { /** - * Info on struct for av_log + * information on struct for av_log * - set by avcodec_alloc_context */ AVClass *av_class; /** - * the average bitrate. - * - encoding: set by user. unused for constant quantizer encoding - * - decoding: set by lavc. 0 or some bitrate if this info is available in the stream + * the average bitrate + * - encoding: Set by user; unused for constant quantizer encoding. + * - decoding: Set by libavcodec. 0 or some bitrate if this info is available in the stream. */ int bit_rate; /** * number of bits the bitstream is allowed to diverge from the reference. * the reference can be CBR (for CBR pass1) or VBR (for pass2) - * - encoding: set by user. unused for constant quantizer encoding + * - encoding: Set by user; unused for constant quantizer encoding. * - decoding: unused */ int bit_rate_tolerance; /** * CODEC_FLAG_*. - * - encoding: set by user. - * - decoding: set by user. + * - encoding: Set by user. + * - decoding: Set by user. */ int flags; /** - * some codecs needs additionnal format info. It is stored here - * if any muxer uses this then ALL demuxers/parsers AND encoders for the specific codec MUST set it correctly - * too otherwise stream copy breaks - * in general use of this field by muxers is not recommanded - * - encoding: set by lavc. - * - decoding: set by lavc. (FIXME is this ok?) + * Some codecs need additional format info. It is stored here. + * If any muxer uses this then ALL demuxers/parsers AND encoders for the + * specific codec MUST set it correctly otherwise stream copy breaks. + * In general use of this field by muxers is not recommanded. + * - encoding: Set by libavcodec. + * - decoding: Set by libavcodec. (FIXME: Is this OK?) */ int sub_id; /** - * motion estimation algorithm used for video coding. + * Motion estimation algorithm used for video coding. * 1 (zero), 2 (full), 3 (log), 4 (phods), 5 (epzs), 6 (x1), 7 (hex), * 8 (umh), 9 (iter) [7, 8 are x264 specific, 9 is snow specific] * - encoding: MUST be set by user. @@ -769,26 +771,26 @@ typedef struct AVCodecContext { int me_method; /** - * some codecs need / can use extra-data like huffman tables. - * mjpeg: huffman tables + * some codecs need / can use extradata like Huffman tables. + * mjpeg: Huffman tables * rv10: additional flags * mpeg4: global headers (they can be in the bitstream or here) - * the allocated memory should be FF_INPUT_BUFFER_PADDING_SIZE bytes larger - * then extradata_size to avoid prolems if its read with the bitstream reader - * the bytewise contents of extradata must not depend on the architecture or cpu endianness - * - encoding: set/allocated/freed by lavc. - * - decoding: set/allocated/freed by user. + * The allocated memory should be FF_INPUT_BUFFER_PADDING_SIZE bytes larger + * than extradata_size to avoid prolems if it is read with the bitstream reader. + * The bytewise contents of extradata must not depend on the architecture or CPU endianness. + * - encoding: Set/allocated/freed by libavcodec. + * - decoding: Set/allocated/freed by user. */ uint8_t *extradata; int extradata_size; /** - * this is the fundamental unit of time (in seconds) in terms - * of which frame timestamps are represented. for fixed-fps content, + * This is the fundamental unit of time (in seconds) in terms + * of which frame timestamps are represented. For fixed-fps content, * timebase should be 1/framerate and timestamp increments should be * identically 1. - * - encoding: MUST be set by user - * - decoding: set by lavc. + * - encoding: MUST be set by user. + * - decoding: Set by libavcodec. */ AVRational time_base; @@ -796,43 +798,43 @@ typedef struct AVCodecContext { /** * picture width / height. * - encoding: MUST be set by user. - * - decoding: set by lavc. - * Note, for compatibility its possible to set this instead of - * coded_width/height before decoding + * - decoding: Set by libavcodec. + * Note: For compatibility it is possible to set this instead of + * coded_width/height before decoding. */ int width, height; #define FF_ASPECT_EXTENDED 15 /** - * the number of pictures in a group of pitures, or 0 for intra_only. - * - encoding: set by user. + * the number of pictures in a group of pictures, or 0 for intra_only + * - encoding: Set by user. * - decoding: unused */ int gop_size; /** - * pixel format, see PIX_FMT_xxx. - * - encoding: set by user. - * - decoding: set by lavc. + * Pixel format, see PIX_FMT_xxx. + * - encoding: Set by user. + * - decoding: Set by libavcodec. */ enum PixelFormat pix_fmt; /** - * Frame rate emulation. If not zero lower layer (i.e. format handler) + * Frame rate emulation. If not zero, the lower layer (i.e. format handler) * has to read frames at native frame rate. - * - encoding: set by user. - * - decoding: unused. + * - encoding: Set by user. + * - decoding: unused */ int rate_emu; /** - * if non NULL, 'draw_horiz_band' is called by the libavcodec - * decoder to draw an horizontal band. It improve cache usage. Not + * If non NULL, 'draw_horiz_band' is called by the libavcodec + * decoder to draw a horizontal band. It improves cache usage. Not * all codecs can do that. You must check the codec capabilities - * before + * beforehand. * - encoding: unused - * - decoding: set by user. + * - decoding: Set by user. * @param height the height of the slice * @param y the y position of the slice * @param type 1->top field, 2->bottom field, 3->frame @@ -843,28 +845,28 @@ typedef struct AVCodecContext { int y, int type, int height); /* audio only */ - int sample_rate; ///< samples per sec + int sample_rate; ///< samples per second int channels; /** - * audio sample format. - * - encoding: set by user. - * - decoding: set by lavc. + * audio sample format + * - encoding: Set by user. + * - decoding: Set by libavcodec. */ - enum SampleFormat sample_fmt; ///< sample format, currenly unused + enum SampleFormat sample_fmt; ///< sample format, currently unused - /* the following data should not be initialized */ + /* The following data should not be initialized. */ /** - * samples per packet. initialized when calling 'init' + * Samples per packet, initialized when calling 'init'. */ int frame_size; int frame_number; ///< audio or video frame number - int real_pict_num; ///< returns the real picture number of previous encoded frame + int real_pict_num; ///< Returns the real picture number of previous encoded frame. /** - * number of frames the decoded output will be delayed relative to + * Number of frames the decoded output will be delayed relative to * the encoded input. - * - encoding: set by lavc. + * - encoding: Set by libavcodec. * - decoding: unused */ int delay; @@ -874,37 +876,37 @@ typedef struct AVCodecContext { float qblur; ///< amount of qscale smoothing over time (0.0-1.0) /** - * minimum quantizer. - * - encoding: set by user. + * minimum quantizer + * - encoding: Set by user. * - decoding: unused */ int qmin; /** - * maximum quantizer. - * - encoding: set by user. + * maximum quantizer + * - encoding: Set by user. * - decoding: unused */ int qmax; /** - * maximum quantizer difference between frames. - * - encoding: set by user. + * maximum quantizer difference between frames + * - encoding: Set by user. * - decoding: unused */ int max_qdiff; /** - * maximum number of b frames between non b frames. - * note: the output will be delayed by max_b_frames+1 relative to the input - * - encoding: set by user. + * maximum number of B-frames between non-B-frames + * Note: The output will be delayed by max_b_frames+1 relative to the input. + * - encoding: Set by user. * - decoding: unused */ int max_b_frames; /** - * qscale factor between ip and b frames. - * - encoding: set by user. + * qscale factor between IP and B-frames + * - encoding: Set by user. * - decoding: unused */ float b_quant_factor; @@ -916,9 +918,9 @@ typedef struct AVCodecContext { int b_frame_strategy; /** - * hurry up amount. + * hurry up amount * - encoding: unused - * - decoding: set by user. 1-> skip b frames, 2-> skip idct/dequant too, 5-> skip everything except header + * - decoding: Set by user. 1-> Skip B-frames, 2-> Skip IDCT/dequant too, 5-> Skip everything except header * @deprecated Deprecated in favor of skip_idct and skip_frame. */ int hurry_up; @@ -933,19 +935,19 @@ typedef struct AVCodecContext { #endif int rtp_payload_size; /* The size of the RTP payload: the coder will */ - /* do it's best to deliver a chunk with size */ + /* do its best to deliver a chunk with size */ /* below rtp_payload_size, the chunk will start */ - /* with a start code on some codecs like H.263 */ + /* with a start code on some codecs like H.263. */ /* This doesn't take account of any particular */ - /* headers inside the transmited RTP payload */ + /* headers inside the transmitted RTP payload. */ - /* The RTP callback: This function is called */ - /* every time the encoder has a packet to send */ - /* Depends on the encoder if the data starts */ - /* with a Start Code (it should) H.263 does. */ - /* mb_nb contains the number of macroblocks */ - /* encoded in the RTP payload */ + /* The RTP callback: This function is called */ + /* every time the encoder has a packet to send. */ + /* It depends on the encoder if the data starts */ + /* with a Start Code (it should). H.263 does. */ + /* mb_nb contains the number of macroblocks */ + /* encoded in the RTP payload. */ void (*rtp_callback)(struct AVCodecContext *avctx, void *data, int size, int mb_nb); /* statistics, used for 2-pass encoding */ @@ -959,16 +961,16 @@ typedef struct AVCodecContext { int misc_bits; /** - * number of bits used for the previously encoded frame. - * - encoding: set by lavc + * number of bits used for the previously encoded frame + * - encoding: Set by libavcodec. * - decoding: unused */ int frame_bits; /** - * private data of the user, can be used to carry app specific stuff. - * - encoding: set by user - * - decoding: set by user + * Private data of the user, can be used to carry app specific stuff. + * - encoding: Set by user. + * - decoding: Set by user. */ void *opaque; @@ -978,23 +980,23 @@ typedef struct AVCodecContext { /** * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A'). - * this is used to workaround some encoder bugs - * a demuxer should set this to what is stored in the field used to identify the codec - * if there are mutiple such fields in a container then the demuxer should choose the one - * which maximizes the information about the used codec - * if the codec tag field in a container is larger then 32bit then the demxuer should - * remap the longer id to 32bit with a table or other structure alternatively a new + * This is used to work around some encoder bugs. + * A demuxer should set this to what is stored in the field used to identify the codec. + * If there are multiple such fields in a container then the demuxer should choose the one + * which maximizes the information about the used codec. + * If the codec tag field in a container is larger then 32 bits then the demuxer should + * remap the longer ID to 32 bits with a table or other structure. Alternatively a new * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated - * first - * - encoding: set by user, if not then the default based on codec_id will be used - * - decoding: set by user, will be converted to upper case by lavc during init + * first. + * - encoding: Set by user, if not then the default based on codec_id will be used. + * - decoding: Set by user, will be converted to uppercase by libavcodec during init. */ unsigned int codec_tag; /** - * workaround bugs in encoders which sometimes cannot be detected automatically. - * - encoding: set by user - * - decoding: set by user + * Work around bugs in encoders which sometimes cannot be detected automatically. + * - encoding: Set by user + * - decoding: Set by user */ int workaround_bugs; #define FF_BUG_AUTODETECT 1 ///< autodetection @@ -1003,7 +1005,7 @@ typedef struct AVCodecContext { #define FF_BUG_UMP4 8 #define FF_BUG_NO_PADDING 16 #define FF_BUG_AMV 32 -#define FF_BUG_AC_VLC 0 ///< will be removed, libavcodec can now handle these non compliant files by default +#define FF_BUG_AC_VLC 0 ///< Will be removed, libavcodec can now handle these non-compliant files by default. #define FF_BUG_QPEL_CHROMA 64 #define FF_BUG_STD_QPEL 128 #define FF_BUG_QPEL_CHROMA2 256 @@ -1011,49 +1013,49 @@ typedef struct AVCodecContext { #define FF_BUG_EDGE 1024 #define FF_BUG_HPEL_CHROMA 2048 #define FF_BUG_DC_CLIP 4096 -#define FF_BUG_MS 8192 ///< workaround various bugs in microsofts broken decoders -//#define FF_BUG_FAKE_SCALABILITY 16 //autodetection should work 100% +#define FF_BUG_MS 8192 ///< Work around various bugs in Microsoft's broken decoders. +//#define FF_BUG_FAKE_SCALABILITY 16 //Autodetection should work 100%. /** - * luma single coeff elimination threshold. - * - encoding: set by user + * luma single coefficient elimination threshold + * - encoding: Set by user. * - decoding: unused */ int luma_elim_threshold; /** - * chroma single coeff elimination threshold. - * - encoding: set by user + * chroma single coeff elimination threshold + * - encoding: Set by user. * - decoding: unused */ int chroma_elim_threshold; /** - * strictly follow the std (MPEG4, ...). - * - encoding: set by user + * strictly follow the standard (MPEG4, ...). + * - encoding: Set by user. * - decoding: unused */ int strict_std_compliance; -#define FF_COMPLIANCE_VERY_STRICT 2 ///< strictly conform to a older more strict version of the spec or reference software -#define FF_COMPLIANCE_STRICT 1 ///< strictly conform to all the things in the spec no matter what consequences +#define FF_COMPLIANCE_VERY_STRICT 2 ///< Strictly conform to a older more strict version of the spec or reference software. +#define FF_COMPLIANCE_STRICT 1 ///< Strictly conform to all the things in the spec no matter what consequences. #define FF_COMPLIANCE_NORMAL 0 -#define FF_COMPLIANCE_INOFFICIAL -1 ///< allow inofficial extensions -#define FF_COMPLIANCE_EXPERIMENTAL -2 ///< allow non standarized experimental things +#define FF_COMPLIANCE_INOFFICIAL -1 ///< Allow inofficial extensions. +#define FF_COMPLIANCE_EXPERIMENTAL -2 ///< Allow nonstandardized experimental things. /** - * qscale offset between ip and b frames. - * if > 0 then the last p frame quantizer will be used (q= lastp_q*factor+offset) - * if < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset) - * - encoding: set by user. + * qscale offset between IP and B-frames + * If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset). + * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset). + * - encoding: Set by user. * - decoding: unused */ float b_quant_offset; /** - * error resilience higher values will detect more errors but may missdetect - * some more or less valid parts as errors. + * Error resilience; higher values will detect more errors but may + * misdetect some more or less valid parts as errors. * - encoding: unused - * - decoding: set by user + * - decoding: Set by user. */ int error_resilience; #define FF_ER_CAREFUL 1 @@ -1062,67 +1064,67 @@ typedef struct AVCodecContext { #define FF_ER_VERY_AGGRESSIVE 4 /** - * called at the beginning of each frame to get a buffer for it. - * if pic.reference is set then the frame will be read later by lavc + * Called at the beginning of each frame to get a buffer for it. + * If pic.reference is set then the frame will be read later by libavcodec. * avcodec_align_dimensions() should be used to find the required width and - * height, as they normally need to be rounded up to the next multiple of 16 + * height, as they normally need to be rounded up to the next multiple of 16. * - encoding: unused - * - decoding: set by lavc, user can override + * - decoding: Set by libavcodec., user can override. */ int (*get_buffer)(struct AVCodecContext *c, AVFrame *pic); /** - * called to release buffers which where allocated with get_buffer. - * a released buffer can be reused in get_buffer() - * pic.data[*] must be set to NULL + * Called to release buffers which where allocated with get_buffer. + * A released buffer can be reused in get_buffer(). + * pic.data[*] must be set to NULL. * - encoding: unused - * - decoding: set by lavc, user can override + * - decoding: Set by libavcodec., user can override. */ void (*release_buffer)(struct AVCodecContext *c, AVFrame *pic); /** - * if 1 the stream has a 1 frame delay during decoding. - * - encoding: set by lavc - * - decoding: set by lavc + * If 1 the stream has a 1 frame delay during decoding. + * - encoding: Set by libavcodec. + * - decoding: Set by libavcodec. */ int has_b_frames; /** * number of bytes per packet if constant and known or 0 - * used by some WAV based audio codecs + * Used by some WAV based audio codecs. */ int block_align; - int parse_only; /* - decoding only: if true, only parsing is done + int parse_only; /* - decoding only: If true, only parsing is done (function avcodec_parse_frame()). The frame data is returned. Only MPEG codecs support this now. */ /** - * 0-> h263 quant 1-> mpeg quant. - * - encoding: set by user. + * 0-> h263 quant 1-> mpeg quant + * - encoding: Set by user. * - decoding: unused */ int mpeg_quant; /** - * pass1 encoding statistics output buffer. - * - encoding: set by lavc + * pass1 encoding statistics output buffer + * - encoding: Set by libavcodec. * - decoding: unused */ char *stats_out; /** - * pass2 encoding statistics input buffer. - * concatenated stuff from stats_out of pass1 should be placed here - * - encoding: allocated/set/freed by user + * pass2 encoding statistics input buffer + * Concatenated stuff from stats_out of pass1 should be placed here. + * - encoding: Allocated/set/freed by user. * - decoding: unused */ char *stats_in; /** - * ratecontrol qmin qmax limiting method. - * 0-> clipping, 1-> use a nice continous function to limit qscale wthin qmin/qmax - * - encoding: set by user. + * ratecontrol qmin qmax limiting method + * 0-> clipping, 1-> use a nice continous function to limit qscale wthin qmin/qmax. + * - encoding: Set by user. * - decoding: unused */ float rc_qsquish; @@ -1131,68 +1133,68 @@ typedef struct AVCodecContext { int rc_qmod_freq; /** - * ratecontrol override, see RcOverride. - * - encoding: allocated/set/freed by user. + * ratecontrol override, see RcOverride + * - encoding: Allocated/set/freed by user. * - decoding: unused */ RcOverride *rc_override; int rc_override_count; /** - * rate control equation. - * - encoding: set by user + * rate control equation + * - encoding: Set by user * - decoding: unused */ char *rc_eq; /** - * maximum bitrate. - * - encoding: set by user. + * maximum bitrate + * - encoding: Set by user. * - decoding: unused */ int rc_max_rate; /** - * minimum bitrate. - * - encoding: set by user. + * minimum bitrate + * - encoding: Set by user. * - decoding: unused */ int rc_min_rate; /** - * decoder bitstream buffer size. - * - encoding: set by user. + * decoder bitstream buffer size + * - encoding: Set by user. * - decoding: unused */ int rc_buffer_size; float rc_buffer_aggressivity; /** - * qscale factor between p and i frames. - * if > 0 then the last p frame quantizer will be used (q= lastp_q*factor+offset) - * if < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset) - * - encoding: set by user. + * qscale factor between P and I-frames + * If > 0 then the last p frame quantizer will be used (q= lastp_q*factor+offset). + * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset). + * - encoding: Set by user. * - decoding: unused */ float i_quant_factor; /** - * qscale offset between p and i frames. - * - encoding: set by user. + * qscale offset between P and I-frames + * - encoding: Set by user. * - decoding: unused */ float i_quant_offset; /** - * initial complexity for pass1 ratecontrol. - * - encoding: set by user. + * initial complexity for pass1 ratecontrol + * - encoding: Set by user. * - decoding: unused */ float rc_initial_cplx; /** - * dct algorithm, see FF_DCT_* below. - * - encoding: set by user + * DCT algorithm, see FF_DCT_* below + * - encoding: Set by user. * - decoding: unused */ int dct_algo; @@ -1205,36 +1207,36 @@ typedef struct AVCodecContext { #define FF_DCT_FAAN 6 /** - * luminance masking (0-> disabled). - * - encoding: set by user + * luminance masking (0-> disabled) + * - encoding: Set by user. * - decoding: unused */ float lumi_masking; /** - * temporary complexity masking (0-> disabled). - * - encoding: set by user + * temporary complexity masking (0-> disabled) + * - encoding: Set by user. * - decoding: unused */ float temporal_cplx_masking; /** - * spatial complexity masking (0-> disabled). - * - encoding: set by user + * spatial complexity masking (0-> disabled) + * - encoding: Set by user. * - decoding: unused */ float spatial_cplx_masking; /** - * p block masking (0-> disabled). - * - encoding: set by user + * p block masking (0-> disabled) + * - encoding: Set by user. * - decoding: unused */ float p_masking; /** - * darkness masking (0-> disabled). - * - encoding: set by user + * darkness masking (0-> disabled) + * - encoding: Set by user. * - decoding: unused */ float dark_masking; @@ -1244,9 +1246,9 @@ typedef struct AVCodecContext { int unused; /** - * idct algorithm, see FF_IDCT_* below. - * - encoding: set by user - * - decoding: set by user + * IDCT algorithm, see FF_IDCT_* below. + * - encoding: Set by user. + * - decoding: Set by user. */ int idct_algo; #define FF_IDCT_AUTO 0 @@ -1269,22 +1271,22 @@ typedef struct AVCodecContext { #define FF_IDCT_SIMPLEARMV6 17 /** - * slice count. - * - encoding: set by lavc - * - decoding: set by user (or 0) + * slice count + * - encoding: Set by libavcodec. + * - decoding: Set by user (or 0). */ int slice_count; /** - * slice offsets in the frame in bytes. - * - encoding: set/allocated by lavc - * - decoding: set/allocated by user (or NULL) + * slice offsets in the frame in bytes + * - encoding: Set/allocated by libavcodec. + * - decoding: Set/allocated by user (or NULL). */ int *slice_offset; /** - * error concealment flags. + * error concealment flags * - encoding: unused - * - decoding: set by user + * - decoding: Set by user. */ int error_concealment; #define FF_EC_GUESS_MVS 1 @@ -1294,12 +1296,12 @@ typedef struct AVCodecContext { * dsp_mask could be add used to disable unwanted CPU features * CPU features (i.e. MMX, SSE. ...) * - * with FORCE flag you may instead enable given CPU features - * (Dangerous: usable in case of misdetection, improper usage however will - * result into program crash) + * With the FORCE flag you may instead enable given CPU features. + * (Dangerous: Usable in case of misdetection, improper usage however will + * result into program crash.) */ unsigned dsp_mask; -#define FF_MM_FORCE 0x80000000 /* force usage of selected flags (OR) */ +#define FF_MM_FORCE 0x80000000 /* Force usage of selected flags (OR) */ /* lower 16 bits - CPU features */ #ifdef HAVE_MMX #define FF_MM_MMX 0x0001 /* standard MMX */ @@ -1315,14 +1317,14 @@ typedef struct AVCodecContext { /** * bits per sample/pixel from the demuxer (needed for huffyuv). - * - encoding: set by lavc - * - decoding: set by user + * - encoding: Set by libavcodec. + * - decoding: Set by user. */ int bits_per_sample; /** - * prediction method (needed for huffyuv). - * - encoding: set by user + * prediction method (needed for huffyuv) + * - encoding: Set by user. * - decoding: unused */ int prediction_method; @@ -1331,24 +1333,24 @@ typedef struct AVCodecContext { #define FF_PRED_MEDIAN 2 /** - * sample aspect ratio (0 if unknown). - * numerator and denominator must be relative prime and smaller then 256 for some video standards - * - encoding: set by user. - * - decoding: set by lavc. + * sample aspect ratio (0 if unknown) + * Numerator and denominator must be relatively prime and smaller than 256 for some video standards. + * - encoding: Set by user. + * - decoding: Set by libavcodec. */ AVRational sample_aspect_ratio; /** - * the picture in the bitstream. - * - encoding: set by lavc - * - decoding: set by lavc + * the picture in the bitstream + * - encoding: Set by libavcodec. + * - decoding: Set by libavcodec. */ AVFrame *coded_frame; /** - * debug. - * - encoding: set by user. - * - decoding: set by user. + * debug + * - encoding: Set by user. + * - decoding: Set by user. */ int debug; #define FF_DEBUG_PICT_INFO 1 @@ -1368,9 +1370,9 @@ typedef struct AVCodecContext { #define FF_DEBUG_VIS_MB_TYPE 0x00004000 /** - * debug. - * - encoding: set by user. - * - decoding: set by user. + * debug + * - encoding: Set by user. + * - decoding: Set by user. */ int debug_mv; #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 //visualize forward predicted MVs of P frames @@ -1378,47 +1380,47 @@ typedef struct AVCodecContext { #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames /** - * error. - * - encoding: set by lavc if flags&CODEC_FLAG_PSNR + * error + * - encoding: Set by libavcodec if flags&CODEC_FLAG_PSNR. * - decoding: unused */ uint64_t error[4]; /** - * minimum MB quantizer. + * minimum MB quantizer * - encoding: unused * - decoding: unused */ int mb_qmin; /** - * maximum MB quantizer. + * maximum MB quantizer * - encoding: unused * - decoding: unused */ int mb_qmax; /** - * motion estimation compare function. - * - encoding: set by user. + * motion estimation comparison function + * - encoding: Set by user. * - decoding: unused */ int me_cmp; /** - * subpixel motion estimation compare function. - * - encoding: set by user. + * subpixel motion estimation comparison function + * - encoding: Set by user. * - decoding: unused */ int me_sub_cmp; /** - * macroblock compare function (not supported yet). - * - encoding: set by user. + * macroblock comparison function (not supported yet) + * - encoding: Set by user. * - decoding: unused */ int mb_cmp; /** - * interlaced dct compare function - * - encoding: set by user. + * interlaced DCT comparison function + * - encoding: Set by user. * - decoding: unused */ int ildct_cmp; @@ -1440,65 +1442,65 @@ typedef struct AVCodecContext { #define FF_CMP_CHROMA 256 /** - * ME diamond size & shape. - * - encoding: set by user. + * ME diamond size & shape + * - encoding: Set by user. * - decoding: unused */ int dia_size; /** - * amount of previous MV predictors (2a+1 x 2a+1 square). - * - encoding: set by user. + * amount of previous MV predictors (2a+1 x 2a+1 square) + * - encoding: Set by user. * - decoding: unused */ int last_predictor_count; /** - * pre pass for motion estimation. - * - encoding: set by user. + * prepass for motion estimation + * - encoding: Set by user. * - decoding: unused */ int pre_me; /** - * motion estimation pre pass compare function. - * - encoding: set by user. + * motion estimation prepass comparison function + * - encoding: Set by user. * - decoding: unused */ int me_pre_cmp; /** - * ME pre pass diamond size & shape. - * - encoding: set by user. + * ME prepass diamond size & shape + * - encoding: Set by user. * - decoding: unused */ int pre_dia_size; /** - * subpel ME quality. - * - encoding: set by user. + * subpel ME quality + * - encoding: Set by user. * - decoding: unused */ int me_subpel_quality; /** - * callback to negotiate the pixelFormat. + * callback to negotiate the pixelFormat * @param fmt is the list of formats which are supported by the codec, - * its terminated by -1 as 0 is a valid format, the formats are ordered by quality - * the first is allways the native one - * @return the choosen format + * it is terminated by -1 as 0 is a valid format, the formats are ordered by quality. + * The first is always the native one. + * @return the chosen format * - encoding: unused - * - decoding: set by user, if not set then the native format will always be choosen + * - decoding: Set by user, if not set the native format will be chosen. */ enum PixelFormat (*get_format)(struct AVCodecContext *s, const enum PixelFormat * fmt); /** - * DTG active format information (additionnal aspect ratio - * information only used in DVB MPEG2 transport streams). 0 if - * not set. + * DTG active format information (additional aspect ratio + * information only used in DVB MPEG-2 transport streams) + * 0 if not set. * - * - encoding: unused. - * - decoding: set by decoder + * - encoding: unused + * - decoding: Set by decoder. */ int dtg_active_format; #define FF_DTG_AFD_SAME 8 @@ -1510,46 +1512,46 @@ typedef struct AVCodecContext { #define FF_DTG_AFD_SP_4_3 15 /** - * Maximum motion estimation search range in subpel units. - * if 0 then no limit + * maximum motion estimation search range in subpel units + * If 0 then no limit. * - * - encoding: set by user. - * - decoding: unused. + * - encoding: Set by user. + * - decoding: unused */ int me_range; /** - * intra quantizer bias. - * - encoding: set by user. + * intra quantizer bias + * - encoding: Set by user. * - decoding: unused */ int intra_quant_bias; #define FF_DEFAULT_QUANT_BIAS 999999 /** - * inter quantizer bias. - * - encoding: set by user. + * inter quantizer bias + * - encoding: Set by user. * - decoding: unused */ int inter_quant_bias; /** - * color table ID. - * - encoding: unused. - * - decoding: which clrtable should be used for 8bit RGB images - * table have to be stored somewhere FIXME + * color table ID + * - encoding: unused + * - decoding: Which clrtable should be used for 8bit RGB images. + * Tables have to be stored somewhere. FIXME */ int color_table_id; /** - * internal_buffer count. - * Don't touch, used by lavc default_get_buffer() + * internal_buffer count + * Don't touch, used by libavcodec default_get_buffer(). */ int internal_buffer_count; /** - * internal_buffers. - * Don't touch, used by lavc default_get_buffer() + * internal_buffers + * Don't touch, used by libavcodec default_get_buffer(). */ void *internal_buffer; @@ -1560,9 +1562,9 @@ typedef struct AVCodecContext { #define FF_QUALITY_SCALE FF_LAMBDA_SCALE //FIXME maybe remove /** - * global quality for codecs which cannot change it per frame. - * this should be proportional to MPEG1/2/4 qscale. - * - encoding: set by user. + * Global quality for codecs which cannot change it per frame. + * This should be proportional to MPEG-1/2/4 qscale. + * - encoding: Set by user. * - decoding: unused */ int global_quality; @@ -1574,14 +1576,14 @@ typedef struct AVCodecContext { #define FF_CODER_TYPE_DEFLATE 4 /** * coder type - * - encoding: set by user. + * - encoding: Set by user. * - decoding: unused */ int coder_type; /** * context model - * - encoding: set by user. + * - encoding: Set by user. * - decoding: unused */ int context_model; @@ -1589,7 +1591,7 @@ typedef struct AVCodecContext { /** * * - encoding: unused - * - decoding: set by user. + * - decoding: Set by user. */ uint8_t * (*realloc)(struct AVCodecContext *s, uint8_t *buf, int buf_size); #endif @@ -1597,7 +1599,7 @@ typedef struct AVCodecContext { /** * slice flags * - encoding: unused - * - decoding: set by user. + * - decoding: Set by user. */ int slice_flags; #define SLICE_FLAG_CODED_ORDER 0x0001 ///< draw_horiz_band() is called in coded order instead of display @@ -1613,7 +1615,7 @@ typedef struct AVCodecContext { /** * macroblock decision mode - * - encoding: set by user. + * - encoding: Set by user. * - decoding: unused */ int mb_decision; @@ -1623,105 +1625,105 @@ typedef struct AVCodecContext { /** * custom intra quantization matrix - * - encoding: set by user, can be NULL - * - decoding: set by lavc + * - encoding: Set by user, can be NULL. + * - decoding: Set by libavcodec. */ uint16_t *intra_matrix; /** * custom inter quantization matrix - * - encoding: set by user, can be NULL - * - decoding: set by lavc + * - encoding: Set by user, can be NULL. + * - decoding: Set by libavcodec. */ uint16_t *inter_matrix; /** * fourcc from the AVI stream header (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A'). - * this is used to workaround some encoder bugs + * This is used to work around some encoder bugs. * - encoding: unused - * - decoding: set by user, will be converted to upper case by lavc during init + * - decoding: Set by user, will be converted to uppercase by libavcodec during init. */ unsigned int stream_codec_tag; /** - * scene change detection threshold. - * 0 is default, larger means fewer detected scene changes - * - encoding: set by user. + * scene change detection threshold + * 0 is default, larger means fewer detected scene changes. + * - encoding: Set by user. * - decoding: unused */ int scenechange_threshold; /** - * minimum lagrange multipler - * - encoding: set by user. + * minimum Lagrange multipler + * - encoding: Set by user. * - decoding: unused */ int lmin; /** - * maximum lagrange multipler - * - encoding: set by user. + * maximum Lagrange multipler + * - encoding: Set by user. * - decoding: unused */ int lmax; /** - * Palette control structure + * palette control structure * - encoding: ??? (no palette-enabled encoder yet) - * - decoding: set by user. + * - decoding: Set by user. */ struct AVPaletteControl *palctrl; /** * noise reduction strength - * - encoding: set by user. + * - encoding: Set by user. * - decoding: unused */ int noise_reduction; /** - * called at the beginning of a frame to get cr buffer for it. - * buffer type (size, hints) must be the same. lavc won't check it. - * lavc will pass previous buffer in pic, function should return + * Called at the beginning of a frame to get cr buffer for it. + * Buffer type (size, hints) must be the same. libavcodec won't check it. + * libavcodec will pass previous buffer in pic, function should return * same buffer or new buffer with old frame "painted" into it. - * if pic.data[0] == NULL must behave like get_buffer(). + * If pic.data[0] == NULL must behave like get_buffer(). * - encoding: unused - * - decoding: set by lavc, user can override + * - decoding: Set by libavcodec., user can override */ int (*reget_buffer)(struct AVCodecContext *c, AVFrame *pic); /** - * number of bits which should be loaded into the rc buffer before decoding starts - * - encoding: set by user. + * Number of bits which should be loaded into the rc buffer before decoding starts. + * - encoding: Set by user. * - decoding: unused */ int rc_initial_buffer_occupancy; /** * - * - encoding: set by user. + * - encoding: Set by user. * - decoding: unused */ int inter_threshold; /** - * CODEC_FLAG2_*. - * - encoding: set by user. - * - decoding: set by user. + * CODEC_FLAG2_* + * - encoding: Set by user. + * - decoding: Set by user. */ int flags2; /** - * simulates errors in the bitstream to test error concealment. - * - encoding: set by user. - * - decoding: unused. + * Simulates errors in the bitstream to test error concealment. + * - encoding: Set by user. + * - decoding: unused */ int error_rate; /** * MP3 antialias algorithm, see FF_AA_* below. * - encoding: unused - * - decoding: set by user + * - decoding: Set by user. */ int antialias_algo; #define FF_AA_AUTO 0 @@ -1729,166 +1731,167 @@ typedef struct AVCodecContext { #define FF_AA_INT 2 #define FF_AA_FLOAT 3 /** - * Quantizer noise shaping. - * - encoding: set by user + * quantizer noise shaping + * - encoding: Set by user. * - decoding: unused */ int quantizer_noise_shaping; /** - * Thread count. + * thread count * is used to decide how many independent tasks should be passed to execute() - * - encoding: set by user - * - decoding: set by user + * - encoding: Set by user. + * - decoding: Set by user. */ int thread_count; /** - * the codec may call this to execute several independent things. it will return only after - * finishing all tasks, the user may replace this with some multithreaded implementation, the - * default implementation will execute the parts serially + * The codec may call this to execute several independent things. + * It will return only after finishing all tasks. + * The user may replace this with some multithreaded implementation, + * the default implementation will execute the parts serially. * @param count the number of things to execute - * - encoding: set by lavc, user can override - * - decoding: set by lavc, user can override + * - encoding: Set by libavcodec, user can override. + * - decoding: Set by libavcodec, user can override. */ int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void **arg2, int *ret, int count); /** - * Thread opaque. - * can be used by execute() to store some per AVCodecContext stuff. + * thread opaque + * Can be used by execute() to store some per AVCodecContext stuff. * - encoding: set by execute() * - decoding: set by execute() */ void *thread_opaque; /** - * Motion estimation threshold. under which no motion estimation is - * performed, but instead the user specified motion vectors are used + * Motion estimation threshold below which no motion estimation is + * performed, but instead the user specified motion vectors are used. * - * - encoding: set by user + * - encoding: Set by user. * - decoding: unused */ int me_threshold; /** - * Macroblock threshold. under which the user specified macroblock types will be used - * - encoding: set by user + * Macroblock threshold below which the user specified macroblock types will be used. + * - encoding: Set by user. * - decoding: unused */ int mb_threshold; /** - * precision of the intra dc coefficient - 8. - * - encoding: set by user + * precision of the intra DC coefficient - 8 + * - encoding: Set by user. * - decoding: unused */ int intra_dc_precision; /** - * noise vs. sse weight for the nsse comparsion function. - * - encoding: set by user + * noise vs. sse weight for the nsse comparsion function + * - encoding: Set by user. * - decoding: unused */ int nsse_weight; /** - * number of macroblock rows at the top which are skipped. + * Number of macroblock rows at the top which are skipped. * - encoding: unused - * - decoding: set by user + * - decoding: Set by user. */ int skip_top; /** - * number of macroblock rows at the bottom which are skipped. + * Number of macroblock rows at the bottom which are skipped. * - encoding: unused - * - decoding: set by user + * - decoding: Set by user. */ int skip_bottom; /** * profile - * - encoding: set by user - * - decoding: set by lavc + * - encoding: Set by user. + * - decoding: Set by libavcodec. */ int profile; #define FF_PROFILE_UNKNOWN -99 /** * level - * - encoding: set by user - * - decoding: set by lavc + * - encoding: Set by user. + * - decoding: Set by libavcodec. */ int level; #define FF_LEVEL_UNKNOWN -99 /** - * low resolution decoding. 1-> 1/2 size, 2->1/4 size + * low resolution decoding, 1-> 1/2 size, 2->1/4 size * - encoding: unused - * - decoding: set by user + * - decoding: Set by user. */ int lowres; /** - * bitsream width / height. may be different from width/height if lowres - * or other things are used + * Bitstream width / height, may be different from width/height if lowres + * or other things are used. * - encoding: unused - * - decoding: set by user before init if known, codec should override / dynamically change if needed + * - decoding: Set by user before init if known. Codec should override / dynamically change if needed. */ int coded_width, coded_height; /** * frame skip threshold - * - encoding: set by user + * - encoding: Set by user. * - decoding: unused */ int frame_skip_threshold; /** * frame skip factor - * - encoding: set by user + * - encoding: Set by user. * - decoding: unused */ int frame_skip_factor; /** * frame skip exponent - * - encoding: set by user + * - encoding: Set by user. * - decoding: unused */ int frame_skip_exp; /** - * frame skip comparission function - * - encoding: set by user. + * frame skip comparison function + * - encoding: Set by user. * - decoding: unused */ int frame_skip_cmp; /** - * border processing masking. raises the quantizer for mbs on the borders + * Border processing masking, raises the quantizer for mbs on the borders * of the picture. - * - encoding: set by user + * - encoding: Set by user. * - decoding: unused */ float border_masking; /** - * minimum MB lagrange multipler. - * - encoding: set by user. + * minimum MB lagrange multipler + * - encoding: Set by user. * - decoding: unused */ int mb_lmin; /** - * maximum MB lagrange multipler. - * - encoding: set by user. + * maximum MB lagrange multipler + * - encoding: Set by user. * - decoding: unused */ int mb_lmax; /** * - * - encoding: set by user. + * - encoding: Set by user. * - decoding: unused */ int me_penalty_compensation; @@ -1896,90 +1899,90 @@ typedef struct AVCodecContext { /** * * - encoding: unused - * - decoding: set by user. + * - decoding: Set by user. */ enum AVDiscard skip_loop_filter; /** * * - encoding: unused - * - decoding: set by user. + * - decoding: Set by user. */ enum AVDiscard skip_idct; /** * * - encoding: unused - * - decoding: set by user. + * - decoding: Set by user. */ enum AVDiscard skip_frame; /** * - * - encoding: set by user. + * - encoding: Set by user. * - decoding: unused */ int bidir_refine; /** * - * - encoding: set by user. + * - encoding: Set by user. * - decoding: unused */ int brd_scale; /** * constant rate factor - quality-based VBR - values ~correspond to qps - * - encoding: set by user. + * - encoding: Set by user. * - decoding: unused */ float crf; /** * constant quantization parameter rate control method - * - encoding: set by user. + * - encoding: Set by user. * - decoding: unused */ int cqp; /** - * minimum gop size - * - encoding: set by user. + * minimum GOP size + * - encoding: Set by user. * - decoding: unused */ int keyint_min; /** * number of reference frames - * - encoding: set by user. + * - encoding: Set by user. * - decoding: unused */ int refs; /** * chroma qp offset from luma - * - encoding: set by user. + * - encoding: Set by user. * - decoding: unused */ int chromaoffset; /** - * influences how often b-frames are used - * - encoding: set by user. + * Influences how often B-frames are used. + * - encoding: Set by user. * - decoding: unused */ int bframebias; /** * trellis RD quantization - * - encoding: set by user. + * - encoding: Set by user. * - decoding: unused */ int trellis; /** - * reduce fluctuations in qp (before curve compression) - * - encoding: set by user. + * Reduce fluctuations in qp (before curve compression). + * - encoding: Set by user. * - decoding: unused */ float complexityblur; @@ -1987,7 +1990,7 @@ typedef struct AVCodecContext { /** * in-loop deblocking filter alphac0 parameter * alpha is in the range -6...6 - * - encoding: set by user. + * - encoding: Set by user. * - decoding: unused */ int deblockalpha; @@ -1995,14 +1998,14 @@ typedef struct AVCodecContext { /** * in-loop deblocking filter beta parameter * beta is in the range -6...6 - * - encoding: set by user. + * - encoding: Set by user. * - decoding: unused */ int deblockbeta; /** * macroblock subpartition sizes to consider - p8x8, p4x4, b8x8, i8x8, i4x4 - * - encoding: set by user. + * - encoding: Set by user. * - decoding: unused */ int partitions; @@ -2013,97 +2016,97 @@ typedef struct AVCodecContext { #define X264_PART_B8X8 0x100 /* Analyse b16x8, b8x16 and b8x8 */ /** - * direct mv prediction mode - 0 (none), 1 (spatial), 2 (temporal) - * - encoding: set by user. + * direct MV prediction mode - 0 (none), 1 (spatial), 2 (temporal) + * - encoding: Set by user. * - decoding: unused */ int directpred; /** - * audio cutoff bandwidth (0 means "automatic") . Currently used only by FAAC - * - encoding: set by user. + * Audio cutoff bandwidth (0 means "automatic"), currently used only by FAAC. + * - encoding: Set by user. * - decoding: unused */ int cutoff; /** - * multiplied by qscale for each frame and added to scene_change_score - * - encoding: set by user. + * Multiplied by qscale for each frame and added to scene_change_score. + * - encoding: Set by user. * - decoding: unused */ int scenechange_factor; /** * - * note: value depends upon the compare functin used for fullpel ME - * - encoding: set by user. + * Note: Value depends upon the compare function used for fullpel ME. + * - encoding: Set by user. * - decoding: unused */ int mv0_threshold; /** - * adjusts sensitivity of b_frame_strategy 1 - * - encoding: set by user. + * Adjusts sensitivity of b_frame_strategy 1. + * - encoding: Set by user. * - decoding: unused */ int b_sensitivity; /** - * - encoding: set by user. + * - encoding: Set by user. * - decoding: unused */ int compression_level; #define FF_COMPRESSION_DEFAULT -1 /** - * sets whether to use LPC mode - used by FLAC encoder - * - encoding: set by user. - * - decoding: unused. + * Sets whether to use LPC mode - used by FLAC encoder. + * - encoding: Set by user. + * - decoding: unused */ int use_lpc; /** * LPC coefficient precision - used by FLAC encoder - * - encoding: set by user. - * - decoding: unused. + * - encoding: Set by user. + * - decoding: unused */ int lpc_coeff_precision; /** - * - encoding: set by user. - * - decoding: unused. + * - encoding: Set by user. + * - decoding: unused */ int min_prediction_order; /** - * - encoding: set by user. - * - decoding: unused. + * - encoding: Set by user. + * - decoding: unused */ int max_prediction_order; /** * search method for selecting prediction order - * - encoding: set by user. - * - decoding: unused. + * - encoding: Set by user. + * - decoding: unused */ int prediction_order_method; /** - * - encoding: set by user. - * - decoding: unused. + * - encoding: Set by user. + * - decoding: unused */ int min_partition_order; /** - * - encoding: set by user. - * - decoding: unused. + * - encoding: Set by user. + * - decoding: unused */ int max_partition_order; /** * GOP timecode frame start number, in non drop frame format - * - encoding: set by user. - * - decoding: unused. + * - encoding: Set by user. + * - decoding: unused */ int64_t timecode_frame_start; } AVCodecContext; @@ -2141,20 +2144,20 @@ typedef struct AVPicture { * AVPaletteControl * This structure defines a method for communicating palette changes * between and demuxer and a decoder. - * this is totally broken, palette changes should be sent as AVPackets + * This is totally broken, palette changes should be sent as AVPackets. */ #define AVPALETTE_SIZE 1024 #define AVPALETTE_COUNT 256 typedef struct AVPaletteControl { - /* demuxer sets this to 1 to indicate the palette has changed; - * decoder resets to 0 */ + /* Demuxer sets this to 1 to indicate the palette has changed; + * decoder resets to 0. */ int palette_changed; /* 4-byte ARGB palette entries, stored in native byte order; note that * the individual palette components should be on a 8-bit scale; if - * the palette data comes from a IBM VGA native format, the component - * data is probably 6 bits in size and needs to be scaled */ + * the palette data comes from an IBM VGA native format, the component + * data is probably 6 bits in size and needs to be scaled. */ unsigned int palette[AVPALETTE_COUNT]; } AVPaletteControl attribute_deprecated; @@ -2371,7 +2374,7 @@ extern AVCodec xl_decoder; extern AVCodec zlib_decoder; extern AVCodec zmbv_decoder; -/* pcm codecs */ +/* PCM codecs */ #define PCM_CODEC(id, name) \ extern AVCodec name ## _decoder; \ extern AVCodec name ## _encoder @@ -2394,7 +2397,7 @@ PCM_CODEC(CODEC_ID_PCM_U24LE, pcm_u24le); PCM_CODEC(CODEC_ID_PCM_U32BE, pcm_u32be); PCM_CODEC(CODEC_ID_PCM_U32LE, pcm_u32le); -/* adpcm codecs */ +/* ADPCM codecs */ PCM_CODEC(CODEC_ID_ADPCM_4XM, adpcm_4xm); PCM_CODEC(CODEC_ID_ADPCM_ADX, adpcm_adx); @@ -2476,23 +2479,23 @@ attribute_deprecated void img_resample_close(ImgReSampleContext *s); /** * Allocate memory for a picture. Call avpicture_free to free it. * - * @param picture the picture to be filled in. - * @param pix_fmt the format of the picture. - * @param width the width of the picture. - * @param height the height of the picture. - * @return Zero if successful, a negative value if not. + * @param picture the picture to be filled in + * @param pix_fmt the format of the picture + * @param width the width of the picture + * @param height the height of the picture + * @return zero if successful, a negative value if not */ int avpicture_alloc(AVPicture *picture, int pix_fmt, int width, int height); /** * Free a picture previously allocated by avpicture_alloc(). * - * @param picture The AVPicture to be freed. + * @param picture the AVPicture to be freed */ void avpicture_free(AVPicture *picture); /** - * Fill in AVPicture's fields. + * Fill in the AVPicture fields. * The fields of the given AVPicture are filled in by using the 'ptr' address * which points to the image data buffer. Depending on the specified picture * format, one or multiple image data pointers and line sizes will be set. @@ -2500,12 +2503,12 @@ void avpicture_free(AVPicture *picture); * the different picture planes and the line sizes of the different planes * will be stored in the lines_sizes array. * - * @param picture AVPicture who's fields are to be filled in + * @param picture AVPicture whose fields are to be filled in * @param ptr Buffer which will contain or contains the actual image data - * @param pix_fmt The format in which the picture data is stored - * @param width The width of the image in pixels - * @param height The height of the image in pixels - * @return Size of the image data in bytes. + * @param pix_fmt The format in which the picture data is stored. + * @param width the width of the image in pixels + * @param height the height of the image in pixels + * @return size of the image data in bytes */ int avpicture_fill(AVPicture *picture, uint8_t *ptr, int pix_fmt, int width, int height); @@ -2516,9 +2519,9 @@ int avpicture_layout(const AVPicture* src, int pix_fmt, int width, int height, * Calculate the size in bytes that a picture of the given width and height * would occupy if stored in the given picture format. * - * @param pix_fmt The given picture format - * @param width The width of the image - * @param height The height of the image + * @param pix_fmt the given picture format + * @param width the width of the image + * @param height the height of the image * @return Image data size in bytes */ int avpicture_get_size(int pix_fmt, int width, int height); @@ -2544,11 +2547,11 @@ unsigned int avcodec_pix_fmt_to_codec_tag(enum PixelFormat p); * other formats. These losses can involve loss of chroma, but also loss of * resolution, loss of color depth, loss due to the color space conversion, loss * of the alpha bits or loss due to color quantization. - * avcodec_get_fix_fmt_loss() informs you on the various types of losses which - * will occur when converting from one pixel format to another. + * avcodec_get_fix_fmt_loss() informs you about the various types of losses + * which will occur when converting from one pixel format to another. * - * @param[in] dst_pix_fmt Destination pixel format. - * @param[in] src_pix_fmt Source pixel format. + * @param[in] dst_pix_fmt destination pixel format + * @param[in] src_pix_fmt source pixel format * @param[in] has_alpha Whether the source pixel format alpha channel is used. * @return Combination of flags informing you what kind of losses will occur. */ @@ -2561,8 +2564,8 @@ int avcodec_get_pix_fmt_loss(int dst_pix_fmt, int src_pix_fmt, * may occur. For example, when converting from RGB24 to GRAY, the color * information will be lost. Similarly, other losses occur when converting from * some formats to other formats. avcodec_find_best_pix_fmt() searches which of - * the given pixel formats should be used to undergo the least amount of losses. - * The pixel formats from which it choses one, are determined by the + * the given pixel formats should be used to suffer the least amount of loss. + * The pixel formats from which it chooses one, are determined by the * \p pix_fmt_mask parameter. * * @code @@ -2571,8 +2574,8 @@ int avcodec_get_pix_fmt_loss(int dst_pix_fmt, int src_pix_fmt, * dst_pix_fmt = avcodec_find_best_pix_fmt(pix_fmt_mask, src_pix_fmt, alpha, &loss); * @endcode * - * @param[in] pix_fmt_mask Bitmask determining which pixel format to choose from. - * @param[in] src_pix_fmt Source pixel format. + * @param[in] pix_fmt_mask bitmask determining which pixel format to choose from + * @param[in] src_pix_fmt source pixel format * @param[in] has_alpha Whether the source pixel format alpha channel is used. * @param[out] loss_ptr Combination of flags informing you what kind of losses will occur. * @return The best pixel format to convert to or -1 if none was found. @@ -2624,7 +2627,7 @@ void register_avcodec(AVCodec *format); /** * Finds an encoder with a matching codec ID. * - * @param id CodecID of the requested encoder. + * @param id CodecID of the requested encoder * @return An encoder if one was found, NULL otherwise. */ AVCodec *avcodec_find_encoder(enum CodecID id); @@ -2632,7 +2635,7 @@ AVCodec *avcodec_find_encoder(enum CodecID id); /** * Finds an encoder with the specified name. * - * @param name Name of the requested encoder. + * @param name name of the requested encoder * @return An encoder if one was found, NULL otherwise. */ AVCodec *avcodec_find_encoder_by_name(const char *name); @@ -2640,7 +2643,7 @@ AVCodec *avcodec_find_encoder_by_name(const char *name); /** * Finds a decoder with a matching codec ID. * - * @param id CodecID of the requested decoder. + * @param id CodecID of the requested decoder * @return A decoder if one was found, NULL otherwise. */ AVCodec *avcodec_find_decoder(enum CodecID id); @@ -2648,7 +2651,7 @@ AVCodec *avcodec_find_decoder(enum CodecID id); /** * Finds an decoder with the specified name. * - * @param name Name of the requested decoder. + * @param name name of the requested decoder * @return A decoder if one was found, NULL otherwise. */ AVCodec *avcodec_find_decoder_by_name(const char *name); @@ -2724,7 +2727,7 @@ int avcodec_default_execute(AVCodecContext *c, int (*func)(AVCodecContext *c2, v * avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for * retrieving a codec. * - * @warning This function is not thread save! + * @warning This function is not thread safe! * * @code * codec = avcodec_find_decoder(CODEC_ID_H264); @@ -2737,9 +2740,9 @@ int avcodec_default_execute(AVCodecContext *c, int (*func)(AVCodecContext *c2, v * exit(1); * @endcode * - * @param avctx The context which will be setup to use the given codec. + * @param avctx The context which will be set up to use the given codec. * @param codec The codec to use within the context. - * @return Zero on success, a negative value on error. + * @return zero on success, a negative value on error * @see avcodec_alloc_context, avcodec_find_decoder, avcodec_find_encoder */ int avcodec_open(AVCodecContext *avctx, AVCodec *codec); @@ -2753,9 +2756,9 @@ attribute_deprecated int avcodec_decode_audio(AVCodecContext *avctx, int16_t *sa /** * Decodes an audio frame from \p buf into \p samples. - * The avcodec_decode_audio2() function decodes a frame of audio from the input + * The avcodec_decode_audio2() function decodes an audio frame from the input * buffer \p buf of size \p buf_size. To decode it, it makes use of the - * audiocodec which was coupled with \p avctx using avcodec_open(). The + * audio codec which was coupled with \p avctx using avcodec_open(). The * resulting decoded frame is stored in output buffer \p samples. If no frame * could be decompressed, \p frame_size_ptr is zero. Otherwise, it is the * decompressed frame size in \e bytes. @@ -2771,7 +2774,7 @@ attribute_deprecated int avcodec_decode_audio(AVCodecContext *avctx, int16_t *sa * no overreading happens for damaged MPEG streams. * * @note You might have to align the input buffer \p buf and output buffer \p - * samples. The alignment requirements depend on the CPU: on some CPUs it isn't + * samples. The alignment requirements depend on the CPU: On some CPUs it isn't * necessary at all, on others it won't work at all if not aligned and on others * it will work but it will have an impact on performance. In practice, the * bitstream should have 4 byte alignment at minimum and all sample data should @@ -2779,11 +2782,11 @@ attribute_deprecated int avcodec_decode_audio(AVCodecContext *avctx, int16_t *sa * the linesize is not a multiple of 16 then there's no sense in aligning the * start of the buffer to 16. * - * @param avctx The codec context. - * @param[out] samples The output buffer. - * @param[in,out] frame_size_ptr The output buffer size in bytes. - * @param[in] buf The input buffer. - * @param[in] buf_size The input buffer size in bytes. + * @param avctx the codec context + * @param[out] samples the output buffer + * @param[in,out] frame_size_ptr the output buffer size in bytes + * @param[in] buf the input buffer + * @param[in] buf_size the input buffer size in bytes * @return On error a negative value is returned, otherwise the number of bytes * used or zero if no frame could be decompressed. */ @@ -2793,9 +2796,9 @@ int avcodec_decode_audio2(AVCodecContext *avctx, int16_t *samples, /** * Decodes a video frame from \p buf into \p picture. - * The avcodec_decode_video() function decodes a frame of video from the input + * The avcodec_decode_video() function decodes a video frame from the input * buffer \p buf of size \p buf_size. To decode it, it makes use of the - * videocodec which was coupled with \p avctx using avcodec_open(). The + * video codec which was coupled with \p avctx using avcodec_open(). The * resulting decoded frame is stored in \p picture. * * @warning The input buffer must be \c FF_INPUT_BUFFER_PADDING_SIZE larger than @@ -2814,11 +2817,11 @@ int avcodec_decode_audio2(AVCodecContext *avctx, int16_t *samples, * the linesize is not a multiple of 16 then there's no sense in aligning the * start of the buffer to 16. * - * @param avctx The codec context. + * @param avctx the codec context * @param[out] picture The AVFrame in which the decoded video frame will be stored. - * @param[in] buf The input buffer. - * @param[in] buf_size The size of the input buffer in bytes. - * @param[in,out] got_picture_ptr Zero if no frame could be decompressed, otherwise, it is non zero. + * @param[in] buf the input buffer + * @param[in] buf_size the size of the input buffer in bytes + * @param[in,out] got_picture_ptr Zero if no frame could be decompressed, otherwise, it is nonzero. * @return On error a negative value is returned, otherwise the number of bytes * used or zero if no frame could be decompressed. */ @@ -2826,9 +2829,9 @@ int avcodec_decode_video(AVCodecContext *avctx, AVFrame *picture, int *got_picture_ptr, uint8_t *buf, int buf_size); -/* decode a subtitle message. return -1 if error, otherwise return the - *number of bytes used. If no subtitle could be decompressed, - *got_sub_ptr is zero. Otherwise, the subtitle is stored in *sub. */ +/* Decode a subtitle message. Return -1 if error, otherwise return the + * number of bytes used. If no subtitle could be decompressed, + * got_sub_ptr is zero. Otherwise, the subtitle is stored in *sub. */ int avcodec_decode_subtitle(AVCodecContext *avctx, AVSubtitle *sub, int *got_sub_ptr, const uint8_t *buf, int buf_size); @@ -2838,17 +2841,17 @@ int avcodec_parse_frame(AVCodecContext *avctx, uint8_t **pdata, /** * Encodes an audio frame from \p samples into \p buf. - * The avcodec_encode_audio() function encodes a frame of audio from the input - * buffer \p samples. To encode it, it makes use of the audiocodec which was + * The avcodec_encode_audio() function encodes an audio frame from the input + * buffer \p samples. To encode it, it makes use of the audio codec which was * coupled with \p avctx using avcodec_open(). The resulting encoded frame is * stored in output buffer \p buf. * * @note The output buffer should be at least \c FF_MIN_BUFFER_SIZE bytes large. * - * @param avctx The codec context. - * @param[out] buf The output buffer. - * @param[in] buf_size The output buffer size. - * @param[in] samples The input buffer containing the samples. + * @param avctx the codec context + * @param[out] buf the output buffer + * @param[in] buf_size the output buffer size + * @param[in] samples the input buffer containing the samples * @return On error a negative value is returned, on succes zero or the number * of bytes used from the input buffer. */ @@ -2857,16 +2860,16 @@ int avcodec_encode_audio(AVCodecContext *avctx, uint8_t *buf, int buf_size, /** * Encodes a video frame from \p pict into \p buf. - * The avcodec_encode_video() function encodes a frame of video from the input - * \p pict. To encode it, it makes use of the videocodec which was coupled with + * The avcodec_encode_video() function encodes a video frame from the input + * \p pict. To encode it, it makes use of the video codec which was coupled with * \p avctx using avcodec_open(). The resulting encoded bytes representing the * frame are stored in the output buffer \p buf. The input picture should be * stored using a specific format, namely \c avctx.pix_fmt. * - * @param avctx The codec context. - * @param[out] buf The output buffer for the bitstream of encoded frame. - * @param[in] buf_size The size of the outputbuffer in bytes. - * @param[in] pict The input picture to encode. + * @param avctx the codec context + * @param[out] buf the output buffer for the bitstream of encoded frame + * @param[in] buf_size the size of the output buffer in bytes + * @param[in] pict the input picture to encode * @return On error a negative value is returned, on success zero or the number * of bytes used from the input buffer. */ @@ -2891,7 +2894,7 @@ void avcodec_default_free_buffers(AVCodecContext *s); /** * Returns a single letter to describe the given picture type \p pict_type. * - * @param[in] pict_type The picture type. + * @param[in] pict_type the picture type * @return A single character representing the picture type. */ char av_get_pict_type_char(int pict_type); @@ -2899,7 +2902,7 @@ char av_get_pict_type_char(int pict_type); /** * Returns codec bits per sample. * - * @param[in] codec_id The codec. + * @param[in] codec_id the codec * @return Number of bits per sample or zero if unknown for the given codec. */ int av_get_bits_per_sample(enum CodecID codec_id); @@ -2913,8 +2916,8 @@ typedef struct AVCodecParserContext { (incremented by each av_parser_parse()) */ int64_t last_frame_offset; /* offset of the last frame */ /* video info */ - int pict_type; /* XXX: put it back in AVCodecContext */ - int repeat_pict; /* XXX: put it back in AVCodecContext */ + int pict_type; /* XXX: Put it back in AVCodecContext. */ + int repeat_pict; /* XXX: Put it back in AVCodecContext. */ int64_t pts; /* pts of the current frame */ int64_t dts; /* dts of the current frame */ @@ -3028,7 +3031,7 @@ void *av_fast_realloc(void *ptr, unsigned int *size, unsigned int min_size); /* for static data only */ /** - * Frees all static arrays and reset their pointers to 0. + * Frees all static arrays and resets their pointers to 0. * Call this function to release all statically allocated tables. */ attribute_deprecated void av_free_static(void); @@ -3039,7 +3042,7 @@ attribute_deprecated void av_free_static(void); * @warning Do not use for normal allocation. * * @param[in] size The amount of memory you need in bytes. - * @return Block of memory of the requested size. + * @return block of memory of the requested size */ attribute_deprecated void *av_mallocz_static(unsigned int size); @@ -3050,13 +3053,13 @@ void av_picture_copy(AVPicture *dst, const AVPicture *src, int pix_fmt, int width, int height); /** - * Crop image top and left side + * Crop image top and left side. */ int av_picture_crop(AVPicture *dst, const AVPicture *src, int pix_fmt, int top_band, int left_band); /** - * Pad image + * Pad image. */ int av_picture_pad(AVPicture *dst, const AVPicture *src, int height, int width, int pix_fmt, int padtop, int padbottom, int padleft, int padright, int *color); @@ -3076,20 +3079,20 @@ extern unsigned int av_xiphlacing(unsigned char *s, unsigned int v); /* error handling */ #if EINVAL > 0 -#define AVERROR(e) (-(e)) /**< returns a negative error code from a POSIX error code, to return from library functions. */ -#define AVUNERROR(e) (-(e)) /**< returns a POSIX error code from a library function error return value. */ +#define AVERROR(e) (-(e)) /**< Returns a negative error code from a POSIX error code, to return from library functions. */ +#define AVUNERROR(e) (-(e)) /**< Returns a POSIX error code from a library function error return value. */ #else -/* some platforms have E* and errno already negated. */ +/* Some platforms have E* and errno already negated. */ #define AVERROR(e) (e) #define AVUNERROR(e) (e) #endif #define AVERROR_UNKNOWN AVERROR(EINVAL) /**< unknown error */ -#define AVERROR_IO AVERROR(EIO) /**< i/o error */ -#define AVERROR_NUMEXPECTED AVERROR(EDOM) /**< number syntax expected in filename */ +#define AVERROR_IO AVERROR(EIO) /**< I/O error */ +#define AVERROR_NUMEXPECTED AVERROR(EDOM) /**< Number syntax expected in filename. */ #define AVERROR_INVALIDDATA AVERROR(EINVAL) /**< invalid data found */ #define AVERROR_NOMEM AVERROR(ENOMEM) /**< not enough memory */ #define AVERROR_NOFMT AVERROR(EILSEQ) /**< unknown format */ -#define AVERROR_NOTSUPP AVERROR(ENOSYS) /**< operation not supported */ +#define AVERROR_NOTSUPP AVERROR(ENOSYS) /**< Operation not supported. */ #ifdef __cplusplus } |