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author | Justin Ruggles <justin.ruggles@gmail.com> | 2010-12-14 14:50:49 +0000 |
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committer | Justin Ruggles <justin.ruggles@gmail.com> | 2010-12-14 14:50:49 +0000 |
commit | 07965463707c61274c4c8073a789cbd2a09a95ab (patch) | |
tree | c3806d011395674432306e67fa79dc4512f2e938 | |
parent | 22c0b03c8f9c978b3dbf086ee367d449ec111b43 (diff) | |
download | ffmpeg-07965463707c61274c4c8073a789cbd2a09a95ab.tar.gz |
cosmetics: Document AC3EncodeContext fields.
Originally committed as revision 25953 to svn://svn.ffmpeg.org/ffmpeg/trunk
-rw-r--r-- | libavcodec/ac3enc.c | 52 |
1 files changed, 28 insertions, 24 deletions
diff --git a/libavcodec/ac3enc.c b/libavcodec/ac3enc.c index 6c0dcb8170..84f6e224a7 100644 --- a/libavcodec/ac3enc.c +++ b/libavcodec/ac3enc.c @@ -34,41 +34,45 @@ #include "audioconvert.h" typedef struct AC3EncodeContext { - PutBitContext pb; + PutBitContext pb; ///< bitstream writer context - int bitstream_id; - int bitstream_mode; + int bitstream_id; ///< bitstream id (bsid) + int bitstream_mode; ///< bitstream mode (bsmod) - int bit_rate; - int sample_rate; + int bit_rate; ///< target bit rate, in bits-per-second + int sample_rate; ///< sampling frequency, in Hz - int frame_size_min; /* minimum frame size in case rounding is necessary */ - int frame_size; /* current frame size in words */ - int frame_size_code; - int bits_written; - int samples_written; + int frame_size_min; ///< minimum frame size in case rounding is necessary + int frame_size; ///< current frame size in words + int frame_size_code; ///< frame size code (frmsizecod) + int bits_written; ///< bit count (used to avg. bitrate) + int samples_written; ///< sample count (used to avg. bitrate) - int fbw_channels; - int channels; - int lfe_on; - int lfe_channel; - int channel_mode; - const uint8_t *channel_map; + int fbw_channels; ///< number of full-bandwidth channels (nfchans) + int channels; ///< total number of channels (nchans) + int lfe_on; ///< indicates if there is an LFE channel (lfeon) + int lfe_channel; ///< channel index of the LFE channel + int channel_mode; ///< channel mode (acmod) + const uint8_t *channel_map; ///< channel map used to reorder channels - int bandwidth_code[AC3_MAX_CHANNELS]; + int bandwidth_code[AC3_MAX_CHANNELS]; ///< bandwidth code (0 to 60) (chbwcod) int nb_coefs[AC3_MAX_CHANNELS]; /* bitrate allocation control */ - int slow_gain_code, slow_decay_code, fast_decay_code, db_per_bit_code, floor_code; - AC3BitAllocParameters bit_alloc; - int coarse_snr_offset; - int fast_gain_code[AC3_MAX_CHANNELS]; - int fine_snr_offset[AC3_MAX_CHANNELS]; + int slow_gain_code; ///< slow gain code (sgaincod) + int slow_decay_code; ///< slow decay code (sdcycod) + int fast_decay_code; ///< fast decay code (fdcycod) + int db_per_bit_code; ///< dB/bit code (dbpbcod) + int floor_code; ///< floor code (floorcod) + AC3BitAllocParameters bit_alloc; ///< bit allocation parameters + int coarse_snr_offset; ///< coarse SNR offsets (csnroffst) + int fast_gain_code[AC3_MAX_CHANNELS]; ///< fast gain codes (signal-to-mask ratio) (fgaincod) + int fine_snr_offset[AC3_MAX_CHANNELS]; ///< fine SNR offsets (fsnroffst) /* mantissa encoding */ - int mant1_cnt, mant2_cnt, mant4_cnt; + int mant1_cnt, mant2_cnt, mant4_cnt; ///< mantissa counts for bap=1,2,4 - int16_t last_samples[AC3_MAX_CHANNELS][AC3_BLOCK_SIZE]; + int16_t last_samples[AC3_MAX_CHANNELS][AC3_BLOCK_SIZE]; ///< last 256 samples from previous frame } AC3EncodeContext; static int16_t costab[64]; |