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author | Justin Ruggles <justin.ruggles@gmail.com> | 2007-12-09 03:23:04 +0000 |
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committer | Justin Ruggles <justin.ruggles@gmail.com> | 2007-12-09 03:23:04 +0000 |
commit | 5ce21342589a93e1713e4e2169f1327be5bf38e5 (patch) | |
tree | 350cf3107bae5c6c08d4659b7152e94e00350956 /libavcodec/ac3.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/ac3.c')
-rw-r--r-- | libavcodec/ac3.c | 112 |
1 files changed, 56 insertions, 56 deletions
diff --git a/libavcodec/ac3.c b/libavcodec/ac3.c index cc436c7e1a..cc80277bc6 100644 --- a/libavcodec/ac3.c +++ b/libavcodec/ac3.c @@ -28,8 +28,8 @@ #include "ac3.h" #include "bitstream.h" -static uint8_t bndtab[51]; -static uint8_t masktab[253]; +static uint8_t band_start_tab[51]; +static uint8_t bin_to_band_tab[253]; static inline int calc_lowcomp1(int a, int b0, int b1, int c) { @@ -53,7 +53,7 @@ static inline int calc_lowcomp(int a, int b0, int b1, int bin) } void ff_ac3_bit_alloc_calc_psd(int8_t *exp, int start, int end, int16_t *psd, - int16_t *bndpsd) + int16_t *band_psd) { int bin, i, j, k, end1, v; @@ -64,26 +64,26 @@ void ff_ac3_bit_alloc_calc_psd(int8_t *exp, int start, int end, int16_t *psd, /* PSD integration */ j=start; - k=masktab[start]; + k=bin_to_band_tab[start]; do { v=psd[j]; j++; - end1 = FFMIN(bndtab[k+1], end); + end1 = FFMIN(band_start_tab[k+1], end); for(i=j;i<end1;i++) { /* logadd */ int adr = FFMIN(FFABS(v - psd[j]) >> 1, 255); v = FFMAX(v, psd[j]) + ff_ac3_log_add_tab[adr]; j++; } - bndpsd[k]=v; + band_psd[k]=v; k++; - } while (end > bndtab[k]); + } while (end > band_start_tab[k]); } -void ff_ac3_bit_alloc_calc_mask(AC3BitAllocParameters *s, int16_t *bndpsd, - int start, int end, int fgain, int is_lfe, - int deltbae, int deltnseg, uint8_t *deltoffst, - uint8_t *deltlen, uint8_t *deltba, +void ff_ac3_bit_alloc_calc_mask(AC3BitAllocParameters *s, int16_t *band_psd, + int start, int end, int fast_gain, int is_lfe, + int dba_mode, int dba_nsegs, uint8_t *dba_offsets, + uint8_t *dba_lengths, uint8_t *dba_values, int16_t *mask) { int16_t excite[50]; /* excitation */ @@ -92,24 +92,24 @@ void ff_ac3_bit_alloc_calc_mask(AC3BitAllocParameters *s, int16_t *bndpsd, int lowcomp, fastleak, slowleak; /* excitation function */ - bndstrt = masktab[start]; - bndend = masktab[end-1] + 1; + bndstrt = bin_to_band_tab[start]; + bndend = bin_to_band_tab[end-1] + 1; if (bndstrt == 0) { lowcomp = 0; - lowcomp = calc_lowcomp1(lowcomp, bndpsd[0], bndpsd[1], 384); - excite[0] = bndpsd[0] - fgain - lowcomp; - lowcomp = calc_lowcomp1(lowcomp, bndpsd[1], bndpsd[2], 384); - excite[1] = bndpsd[1] - fgain - lowcomp; + lowcomp = calc_lowcomp1(lowcomp, band_psd[0], band_psd[1], 384); + excite[0] = band_psd[0] - fast_gain - lowcomp; + lowcomp = calc_lowcomp1(lowcomp, band_psd[1], band_psd[2], 384); + excite[1] = band_psd[1] - fast_gain - lowcomp; begin = 7; for (bin = 2; bin < 7; bin++) { if (!(is_lfe && bin == 6)) - lowcomp = calc_lowcomp1(lowcomp, bndpsd[bin], bndpsd[bin+1], 384); - fastleak = bndpsd[bin] - fgain; - slowleak = bndpsd[bin] - s->sgain; + lowcomp = calc_lowcomp1(lowcomp, band_psd[bin], band_psd[bin+1], 384); + fastleak = band_psd[bin] - fast_gain; + slowleak = band_psd[bin] - s->slow_gain; excite[bin] = fastleak - lowcomp; if (!(is_lfe && bin == 6)) { - if (bndpsd[bin] <= bndpsd[bin+1]) { + if (band_psd[bin] <= band_psd[bin+1]) { begin = bin + 1; break; } @@ -121,10 +121,10 @@ void ff_ac3_bit_alloc_calc_mask(AC3BitAllocParameters *s, int16_t *bndpsd, for (bin = begin; bin < end1; bin++) { if (!(is_lfe && bin == 6)) - lowcomp = calc_lowcomp(lowcomp, bndpsd[bin], bndpsd[bin+1], bin); + lowcomp = calc_lowcomp(lowcomp, band_psd[bin], band_psd[bin+1], bin); - fastleak = FFMAX(fastleak - s->fdecay, bndpsd[bin] - fgain); - slowleak = FFMAX(slowleak - s->sdecay, bndpsd[bin] - s->sgain); + fastleak = FFMAX(fastleak - s->fast_decay, band_psd[bin] - fast_gain); + slowleak = FFMAX(slowleak - s->slow_decay, band_psd[bin] - s->slow_gain); excite[bin] = FFMAX(fastleak - lowcomp, slowleak); } begin = 22; @@ -132,39 +132,39 @@ void ff_ac3_bit_alloc_calc_mask(AC3BitAllocParameters *s, int16_t *bndpsd, /* coupling channel */ begin = bndstrt; - fastleak = (s->cplfleak << 8) + 768; - slowleak = (s->cplsleak << 8) + 768; + fastleak = (s->cpl_fast_leak << 8) + 768; + slowleak = (s->cpl_slow_leak << 8) + 768; } for (bin = begin; bin < bndend; bin++) { - fastleak = FFMAX(fastleak - s->fdecay, bndpsd[bin] - fgain); - slowleak = FFMAX(slowleak - s->sdecay, bndpsd[bin] - s->sgain); + fastleak = FFMAX(fastleak - s->fast_decay, band_psd[bin] - fast_gain); + slowleak = FFMAX(slowleak - s->slow_decay, band_psd[bin] - s->slow_gain); excite[bin] = FFMAX(fastleak, slowleak); } /* compute masking curve */ for (bin = bndstrt; bin < bndend; bin++) { - tmp = s->dbknee - bndpsd[bin]; + tmp = s->db_per_bit - band_psd[bin]; if (tmp > 0) { excite[bin] += tmp >> 2; } - mask[bin] = FFMAX(ff_ac3_hearing_threshold_tab[bin >> s->halfratecod][s->fscod], excite[bin]); + mask[bin] = FFMAX(ff_ac3_hearing_threshold_tab[bin >> s->sr_shift][s->sr_code], excite[bin]); } /* delta bit allocation */ - if (deltbae == DBA_REUSE || deltbae == DBA_NEW) { + if (dba_mode == DBA_REUSE || dba_mode == DBA_NEW) { int band, seg, delta; band = 0; - for (seg = 0; seg < deltnseg; seg++) { - band += deltoffst[seg]; - if (deltba[seg] >= 4) { - delta = (deltba[seg] - 3) << 7; + for (seg = 0; seg < dba_nsegs; seg++) { + band += dba_offsets[seg]; + if (dba_values[seg] >= 4) { + delta = (dba_values[seg] - 3) << 7; } else { - delta = (deltba[seg] - 4) << 7; + delta = (dba_values[seg] - 4) << 7; } - for (k = 0; k < deltlen[seg]; k++) { + for (k = 0; k < dba_lengths[seg]; k++) { mask[band] += delta; band++; } @@ -173,49 +173,49 @@ void ff_ac3_bit_alloc_calc_mask(AC3BitAllocParameters *s, int16_t *bndpsd, } void ff_ac3_bit_alloc_calc_bap(int16_t *mask, int16_t *psd, int start, int end, - int snroffset, int floor, uint8_t *bap) + int snr_offset, int floor, uint8_t *bap) { int i, j, k, end1, v, address; - /* special case, if snroffset is -960, set all bap's to zero */ - if(snroffset == -960) { + /* special case, if snr offset is -960, set all bap's to zero */ + if(snr_offset == -960) { memset(bap, 0, 256); return; } i = start; - j = masktab[start]; + j = bin_to_band_tab[start]; do { - v = (FFMAX(mask[j] - snroffset - floor, 0) & 0x1FE0) + floor; - end1 = FFMIN(bndtab[j] + ff_ac3_critical_band_size_tab[j], end); + v = (FFMAX(mask[j] - snr_offset - floor, 0) & 0x1FE0) + floor; + end1 = FFMIN(band_start_tab[j] + ff_ac3_critical_band_size_tab[j], end); for (k = i; k < end1; k++) { address = av_clip((psd[i] - v) >> 5, 0, 63); bap[i] = ff_ac3_bap_tab[address]; i++; } - } while (end > bndtab[j++]); + } while (end > band_start_tab[j++]); } /* AC3 bit allocation. The algorithm is the one described in the AC3 spec. */ void ac3_parametric_bit_allocation(AC3BitAllocParameters *s, uint8_t *bap, int8_t *exp, int start, int end, - int snroffset, int fgain, int is_lfe, - int deltbae,int deltnseg, - uint8_t *deltoffst, uint8_t *deltlen, - uint8_t *deltba) + int snr_offset, int fast_gain, int is_lfe, + int dba_mode, int dba_nsegs, + uint8_t *dba_offsets, uint8_t *dba_lengths, + uint8_t *dba_values) { int16_t psd[256]; /* scaled exponents */ - int16_t bndpsd[50]; /* interpolated exponents */ + int16_t band_psd[50]; /* interpolated exponents */ int16_t mask[50]; /* masking value */ - ff_ac3_bit_alloc_calc_psd(exp, start, end, psd, bndpsd); + ff_ac3_bit_alloc_calc_psd(exp, start, end, psd, band_psd); - ff_ac3_bit_alloc_calc_mask(s, bndpsd, start, end, fgain, is_lfe, - deltbae, deltnseg, deltoffst, deltlen, deltba, + ff_ac3_bit_alloc_calc_mask(s, band_psd, start, end, fast_gain, is_lfe, + dba_mode, dba_nsegs, dba_offsets, dba_lengths, dba_values, mask); - ff_ac3_bit_alloc_calc_bap(mask, psd, start, end, snroffset, s->floor, bap); + ff_ac3_bit_alloc_calc_bap(mask, psd, start, end, snr_offset, s->floor, bap); } /** @@ -230,10 +230,10 @@ void ac3_common_init(void) k = 0; l = 0; for(i=0;i<50;i++) { - bndtab[i] = l; + band_start_tab[i] = l; v = ff_ac3_critical_band_size_tab[i]; - for(j=0;j<v;j++) masktab[k++]=i; + for(j=0;j<v;j++) bin_to_band_tab[k++]=i; l += v; } - bndtab[50] = l; + band_start_tab[50] = l; } |