diff options
author | Justin Ruggles <justin.ruggles@gmail.com> | 2007-12-09 03:23:04 +0000 |
---|---|---|
committer | Justin Ruggles <justin.ruggles@gmail.com> | 2007-12-09 03:23:04 +0000 |
commit | 5ce21342589a93e1713e4e2169f1327be5bf38e5 (patch) | |
tree | 350cf3107bae5c6c08d4659b7152e94e00350956 /libavcodec/ac3enc.c | |
parent | 66ecf18e3864aa908319e7cb5fd73f308cb4302c (diff) | |
download | ffmpeg-5ce21342589a93e1713e4e2169f1327be5bf38e5.tar.gz |
cosmetics: rename ac3 bit allocation variables
Originally committed as revision 11194 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavcodec/ac3enc.c')
-rw-r--r-- | libavcodec/ac3enc.c | 128 |
1 files changed, 64 insertions, 64 deletions
diff --git a/libavcodec/ac3enc.c b/libavcodec/ac3enc.c index d594905e68..07fc12c45c 100644 --- a/libavcodec/ac3enc.c +++ b/libavcodec/ac3enc.c @@ -42,9 +42,9 @@ typedef struct AC3EncodeContext { unsigned int frame_size; /* current frame size in words */ unsigned int bits_written; unsigned int samples_written; - int halfratecod; + int sr_shift; unsigned int frmsizecod; - unsigned int fscod; /* frequency */ + unsigned int sr_code; /* frequency */ unsigned int acmod; int lfe; unsigned int bsmod; @@ -53,11 +53,11 @@ typedef struct AC3EncodeContext { int nb_coefs[AC3_MAX_CHANNELS]; /* bitrate allocation control */ - int sgaincod, sdecaycod, fdecaycod, dbkneecod, floorcod; + int slow_gain_code, slow_decay_code, fast_decay_code, db_per_bit_code, floor_code; AC3BitAllocParameters bit_alloc; - int csnroffst; - int fgaincod[AC3_MAX_CHANNELS]; - int fsnroffst[AC3_MAX_CHANNELS]; + int coarse_snr_offset; + int fast_gain_code[AC3_MAX_CHANNELS]; + int fine_snr_offset[AC3_MAX_CHANNELS]; /* mantissa encoding */ int mant1_cnt, mant2_cnt, mant4_cnt; } AC3EncodeContext; @@ -438,7 +438,7 @@ static void bit_alloc_masking(AC3EncodeContext *s, int16_t mask[NB_BLOCKS][AC3_MAX_CHANNELS][50]) { int blk, ch; - int16_t bndpsd[NB_BLOCKS][AC3_MAX_CHANNELS][50]; + int16_t band_psd[NB_BLOCKS][AC3_MAX_CHANNELS][50]; for(blk=0; blk<NB_BLOCKS; blk++) { for(ch=0;ch<s->nb_all_channels;ch++) { @@ -448,10 +448,10 @@ static void bit_alloc_masking(AC3EncodeContext *s, } else { ff_ac3_bit_alloc_calc_psd(encoded_exp[blk][ch], 0, s->nb_coefs[ch], - psd[blk][ch], bndpsd[blk][ch]); - ff_ac3_bit_alloc_calc_mask(&s->bit_alloc, bndpsd[blk][ch], + psd[blk][ch], band_psd[blk][ch]); + ff_ac3_bit_alloc_calc_mask(&s->bit_alloc, band_psd[blk][ch], 0, s->nb_coefs[ch], - ff_ac3_fast_gain_tab[s->fgaincod[ch]], + ff_ac3_fast_gain_tab[s->fast_gain_code[ch]], ch == s->lfe_channel, DBA_NONE, 0, NULL, NULL, NULL, mask[blk][ch]); @@ -464,12 +464,12 @@ static int bit_alloc(AC3EncodeContext *s, int16_t mask[NB_BLOCKS][AC3_MAX_CHANNELS][50], int16_t psd[NB_BLOCKS][AC3_MAX_CHANNELS][N/2], uint8_t bap[NB_BLOCKS][AC3_MAX_CHANNELS][N/2], - int frame_bits, int csnroffst, int fsnroffst) + int frame_bits, int coarse_snr_offset, int fine_snr_offset) { int i, ch; - int snroffset; + int snr_offset; - snroffset = (((csnroffst - 15) << 4) + fsnroffst) << 2; + snr_offset = (((coarse_snr_offset - 15) << 4) + fine_snr_offset) << 2; /* compute size */ for(i=0;i<NB_BLOCKS;i++) { @@ -478,7 +478,7 @@ static int bit_alloc(AC3EncodeContext *s, s->mant4_cnt = 0; for(ch=0;ch<s->nb_all_channels;ch++) { ff_ac3_bit_alloc_calc_bap(mask[i][ch], psd[i][ch], 0, - s->nb_coefs[ch], snroffset, + s->nb_coefs[ch], snr_offset, s->bit_alloc.floor, bap[i][ch]); frame_bits += compute_mantissa_size(s, bap[i][ch], s->nb_coefs[ch]); @@ -486,7 +486,7 @@ static int bit_alloc(AC3EncodeContext *s, } #if 0 printf("csnr=%d fsnr=%d frame_bits=%d diff=%d\n", - csnroffst, fsnroffst, frame_bits, + coarse_snr_offset, fine_snr_offset, frame_bits, 16 * s->frame_size - ((frame_bits + 7) & ~7)); #endif return 16 * s->frame_size - frame_bits; @@ -501,29 +501,29 @@ static int compute_bit_allocation(AC3EncodeContext *s, int frame_bits) { int i, ch; - int csnroffst, fsnroffst; + int coarse_snr_offset, fine_snr_offset; uint8_t bap1[NB_BLOCKS][AC3_MAX_CHANNELS][N/2]; int16_t psd[NB_BLOCKS][AC3_MAX_CHANNELS][N/2]; int16_t mask[NB_BLOCKS][AC3_MAX_CHANNELS][50]; static int frame_bits_inc[8] = { 0, 0, 2, 2, 2, 4, 2, 4 }; /* init default parameters */ - s->sdecaycod = 2; - s->fdecaycod = 1; - s->sgaincod = 1; - s->dbkneecod = 2; - s->floorcod = 4; + s->slow_decay_code = 2; + s->fast_decay_code = 1; + s->slow_gain_code = 1; + s->db_per_bit_code = 2; + s->floor_code = 4; for(ch=0;ch<s->nb_all_channels;ch++) - s->fgaincod[ch] = 4; + s->fast_gain_code[ch] = 4; /* compute real values */ - s->bit_alloc.fscod = s->fscod; - s->bit_alloc.halfratecod = s->halfratecod; - s->bit_alloc.sdecay = ff_ac3_slow_decay_tab[s->sdecaycod] >> s->halfratecod; - s->bit_alloc.fdecay = ff_ac3_fast_decay_tab[s->fdecaycod] >> s->halfratecod; - s->bit_alloc.sgain = ff_ac3_slow_gain_tab[s->sgaincod]; - s->bit_alloc.dbknee = ff_ac3_db_per_bit_tab[s->dbkneecod]; - s->bit_alloc.floor = ff_ac3_floor_tab[s->floorcod]; + s->bit_alloc.sr_code = s->sr_code; + s->bit_alloc.sr_shift = s->sr_shift; + s->bit_alloc.slow_decay = ff_ac3_slow_decay_tab[s->slow_decay_code] >> s->sr_shift; + s->bit_alloc.fast_decay = ff_ac3_fast_decay_tab[s->fast_decay_code] >> s->sr_shift; + s->bit_alloc.slow_gain = ff_ac3_slow_gain_tab[s->slow_gain_code]; + s->bit_alloc.db_per_bit = ff_ac3_db_per_bit_tab[s->db_per_bit_code]; + s->bit_alloc.floor = ff_ac3_floor_tab[s->floor_code]; /* header size */ frame_bits += 65; @@ -568,43 +568,43 @@ static int compute_bit_allocation(AC3EncodeContext *s, /* now the big work begins : do the bit allocation. Modify the snr offset until we can pack everything in the requested frame size */ - csnroffst = s->csnroffst; - while (csnroffst >= 0 && - bit_alloc(s, mask, psd, bap, frame_bits, csnroffst, 0) < 0) - csnroffst -= SNR_INC1; - if (csnroffst < 0) { + coarse_snr_offset = s->coarse_snr_offset; + while (coarse_snr_offset >= 0 && + bit_alloc(s, mask, psd, bap, frame_bits, coarse_snr_offset, 0) < 0) + coarse_snr_offset -= SNR_INC1; + if (coarse_snr_offset < 0) { av_log(NULL, AV_LOG_ERROR, "Bit allocation failed, try increasing the bitrate, -ab 384k for example!\n"); return -1; } - while ((csnroffst + SNR_INC1) <= 63 && + while ((coarse_snr_offset + SNR_INC1) <= 63 && bit_alloc(s, mask, psd, bap1, frame_bits, - csnroffst + SNR_INC1, 0) >= 0) { - csnroffst += SNR_INC1; + coarse_snr_offset + SNR_INC1, 0) >= 0) { + coarse_snr_offset += SNR_INC1; memcpy(bap, bap1, sizeof(bap1)); } - while ((csnroffst + 1) <= 63 && - bit_alloc(s, mask, psd, bap1, frame_bits, csnroffst + 1, 0) >= 0) { - csnroffst++; + while ((coarse_snr_offset + 1) <= 63 && + bit_alloc(s, mask, psd, bap1, frame_bits, coarse_snr_offset + 1, 0) >= 0) { + coarse_snr_offset++; memcpy(bap, bap1, sizeof(bap1)); } - fsnroffst = 0; - while ((fsnroffst + SNR_INC1) <= 15 && + fine_snr_offset = 0; + while ((fine_snr_offset + SNR_INC1) <= 15 && bit_alloc(s, mask, psd, bap1, frame_bits, - csnroffst, fsnroffst + SNR_INC1) >= 0) { - fsnroffst += SNR_INC1; + coarse_snr_offset, fine_snr_offset + SNR_INC1) >= 0) { + fine_snr_offset += SNR_INC1; memcpy(bap, bap1, sizeof(bap1)); } - while ((fsnroffst + 1) <= 15 && + while ((fine_snr_offset + 1) <= 15 && bit_alloc(s, mask, psd, bap1, frame_bits, - csnroffst, fsnroffst + 1) >= 0) { - fsnroffst++; + coarse_snr_offset, fine_snr_offset + 1) >= 0) { + fine_snr_offset++; memcpy(bap, bap1, sizeof(bap1)); } - s->csnroffst = csnroffst; + s->coarse_snr_offset = coarse_snr_offset; for(ch=0;ch<s->nb_all_channels;ch++) - s->fsnroffst[ch] = fsnroffst; + s->fine_snr_offset[ch] = fine_snr_offset; #if defined(DEBUG_BITALLOC) { int j; @@ -663,22 +663,22 @@ static int AC3_encode_init(AVCodecContext *avctx) return -1; found: s->sample_rate = freq; - s->halfratecod = i; - s->fscod = j; - s->bsid = 8 + s->halfratecod; + s->sr_shift = i; + s->sr_code = j; + s->bsid = 8 + s->sr_shift; s->bsmod = 0; /* complete main audio service */ /* bitrate & frame size */ bitrate /= 1000; for(i=0;i<19;i++) { - if ((ff_ac3_bitrate_tab[i] >> s->halfratecod) == bitrate) + if ((ff_ac3_bitrate_tab[i] >> s->sr_shift) == bitrate) break; } if (i == 19) return -1; s->bit_rate = bitrate; s->frmsizecod = i << 1; - s->frame_size_min = ff_ac3_frame_size_tab[s->frmsizecod][s->fscod]; + s->frame_size_min = ff_ac3_frame_size_tab[s->frmsizecod][s->sr_code]; s->bits_written = 0; s->samples_written = 0; s->frame_size = s->frame_size_min; @@ -695,7 +695,7 @@ static int AC3_encode_init(AVCodecContext *avctx) s->nb_coefs[s->lfe_channel] = 7; /* fixed */ } /* initial snr offset */ - s->csnroffst = 40; + s->coarse_snr_offset = 40; /* mdct init */ fft_init(MDCT_NBITS - 2); @@ -718,7 +718,7 @@ static void output_frame_header(AC3EncodeContext *s, unsigned char *frame) put_bits(&s->pb, 16, 0x0b77); /* frame header */ put_bits(&s->pb, 16, 0); /* crc1: will be filled later */ - put_bits(&s->pb, 2, s->fscod); + put_bits(&s->pb, 2, s->sr_code); put_bits(&s->pb, 6, s->frmsizecod + (s->frame_size - s->frame_size_min)); put_bits(&s->pb, 5, s->bsid); put_bits(&s->pb, 3, s->bsmod); @@ -900,20 +900,20 @@ static void output_audio_block(AC3EncodeContext *s, baie = (block_num == 0); put_bits(&s->pb, 1, baie); if (baie) { - put_bits(&s->pb, 2, s->sdecaycod); - put_bits(&s->pb, 2, s->fdecaycod); - put_bits(&s->pb, 2, s->sgaincod); - put_bits(&s->pb, 2, s->dbkneecod); - put_bits(&s->pb, 3, s->floorcod); + put_bits(&s->pb, 2, s->slow_decay_code); + put_bits(&s->pb, 2, s->fast_decay_code); + put_bits(&s->pb, 2, s->slow_gain_code); + put_bits(&s->pb, 2, s->db_per_bit_code); + put_bits(&s->pb, 3, s->floor_code); } /* snr offset */ put_bits(&s->pb, 1, baie); /* always present with bai */ if (baie) { - put_bits(&s->pb, 6, s->csnroffst); + put_bits(&s->pb, 6, s->coarse_snr_offset); for(ch=0;ch<s->nb_all_channels;ch++) { - put_bits(&s->pb, 4, s->fsnroffst[ch]); - put_bits(&s->pb, 3, s->fgaincod[ch]); + put_bits(&s->pb, 4, s->fine_snr_offset[ch]); + put_bits(&s->pb, 3, s->fast_gain_code[ch]); } } |