mirror of https://git.ffmpeg.org/ffmpeg.git
utilize multi-stage AC-3 bit allocation. speeds up encoding by 25-30%
Originally committed as revision 8477 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
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447caf7941
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bbd16dea67
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@ -431,10 +431,39 @@ static int compute_mantissa_size(AC3EncodeContext *s, uint8_t *m, int nb_coefs)
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}
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}
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static void bit_alloc_masking(AC3EncodeContext *s,
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uint8_t encoded_exp[NB_BLOCKS][AC3_MAX_CHANNELS][N/2],
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uint8_t exp_strategy[NB_BLOCKS][AC3_MAX_CHANNELS],
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int16_t psd[NB_BLOCKS][AC3_MAX_CHANNELS][N/2],
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int16_t mask[NB_BLOCKS][AC3_MAX_CHANNELS][50])
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{
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int blk, ch;
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int16_t bndpsd[NB_BLOCKS][AC3_MAX_CHANNELS][50];
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for(blk=0; blk<NB_BLOCKS; blk++) {
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for(ch=0;ch<s->nb_all_channels;ch++) {
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if(exp_strategy[blk][ch] == EXP_REUSE) {
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memcpy(psd[blk][ch], psd[blk-1][ch], (N/2)*sizeof(int16_t));
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memcpy(mask[blk][ch], mask[blk-1][ch], 50*sizeof(int16_t));
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} else {
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ff_ac3_bit_alloc_calc_psd(encoded_exp[blk][ch], 0,
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s->nb_coefs[ch],
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psd[blk][ch], bndpsd[blk][ch]);
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ff_ac3_bit_alloc_calc_mask(&s->bit_alloc, bndpsd[blk][ch],
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0, s->nb_coefs[ch],
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ff_fgaintab[s->fgaincod[ch]],
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ch == s->lfe_channel,
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2, 0, NULL, NULL, NULL,
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mask[blk][ch]);
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}
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}
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}
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}
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static int bit_alloc(AC3EncodeContext *s,
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static int bit_alloc(AC3EncodeContext *s,
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int16_t mask[NB_BLOCKS][AC3_MAX_CHANNELS][50],
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int16_t psd[NB_BLOCKS][AC3_MAX_CHANNELS][N/2],
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uint8_t bap[NB_BLOCKS][AC3_MAX_CHANNELS][N/2],
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uint8_t bap[NB_BLOCKS][AC3_MAX_CHANNELS][N/2],
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uint8_t encoded_exp[NB_BLOCKS][AC3_MAX_CHANNELS][N/2],
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uint8_t exp_strategy[NB_BLOCKS][AC3_MAX_CHANNELS],
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int frame_bits, int csnroffst, int fsnroffst)
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int frame_bits, int csnroffst, int fsnroffst)
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{
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{
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int i, ch;
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int i, ch;
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@ -445,14 +474,11 @@ static int bit_alloc(AC3EncodeContext *s,
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s->mant2_cnt = 0;
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s->mant2_cnt = 0;
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s->mant4_cnt = 0;
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s->mant4_cnt = 0;
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for(ch=0;ch<s->nb_all_channels;ch++) {
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for(ch=0;ch<s->nb_all_channels;ch++) {
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ac3_parametric_bit_allocation(&s->bit_alloc,
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ff_ac3_bit_alloc_calc_bap(mask[i][ch], psd[i][ch],
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bap[i][ch], (int8_t *)encoded_exp[i][ch],
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0, s->nb_coefs[ch],
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0, s->nb_coefs[ch],
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(((csnroffst-15) << 4) +
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(((csnroffst-15) << 4) +
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fsnroffst) << 2,
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fsnroffst) << 2,
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ff_fgaintab[s->fgaincod[ch]],
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s->bit_alloc.floor, bap[i][ch]);
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ch == s->lfe_channel,
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2, 0, NULL, NULL, NULL);
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frame_bits += compute_mantissa_size(s, bap[i][ch],
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frame_bits += compute_mantissa_size(s, bap[i][ch],
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s->nb_coefs[ch]);
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s->nb_coefs[ch]);
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}
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}
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@ -476,6 +502,8 @@ static int compute_bit_allocation(AC3EncodeContext *s,
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int i, ch;
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int i, ch;
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int csnroffst, fsnroffst;
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int csnroffst, fsnroffst;
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uint8_t bap1[NB_BLOCKS][AC3_MAX_CHANNELS][N/2];
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uint8_t bap1[NB_BLOCKS][AC3_MAX_CHANNELS][N/2];
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int16_t psd[NB_BLOCKS][AC3_MAX_CHANNELS][N/2];
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int16_t mask[NB_BLOCKS][AC3_MAX_CHANNELS][50];
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static int frame_bits_inc[8] = { 0, 0, 2, 2, 2, 4, 2, 4 };
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static int frame_bits_inc[8] = { 0, 0, 2, 2, 2, 4, 2, 4 };
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/* init default parameters */
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/* init default parameters */
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@ -533,38 +561,41 @@ static int compute_bit_allocation(AC3EncodeContext *s,
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/* CRC */
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/* CRC */
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frame_bits += 16;
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frame_bits += 16;
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/* calculate psd and masking curve before doing bit allocation */
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bit_alloc_masking(s, encoded_exp, exp_strategy, psd, mask);
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/* now the big work begins : do the bit allocation. Modify the snr
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/* now the big work begins : do the bit allocation. Modify the snr
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offset until we can pack everything in the requested frame size */
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offset until we can pack everything in the requested frame size */
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csnroffst = s->csnroffst;
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csnroffst = s->csnroffst;
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while (csnroffst >= 0 &&
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while (csnroffst >= 0 &&
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bit_alloc(s, bap, encoded_exp, exp_strategy, frame_bits, csnroffst, 0) < 0)
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bit_alloc(s, mask, psd, bap, frame_bits, csnroffst, 0) < 0)
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csnroffst -= SNR_INC1;
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csnroffst -= SNR_INC1;
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if (csnroffst < 0) {
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if (csnroffst < 0) {
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av_log(NULL, AV_LOG_ERROR, "Bit allocation failed, try increasing the bitrate, -ab 384 for example!\n");
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av_log(NULL, AV_LOG_ERROR, "Bit allocation failed, try increasing the bitrate, -ab 384 for example!\n");
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return -1;
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return -1;
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}
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}
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while ((csnroffst + SNR_INC1) <= 63 &&
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while ((csnroffst + SNR_INC1) <= 63 &&
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bit_alloc(s, bap1, encoded_exp, exp_strategy, frame_bits,
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bit_alloc(s, mask, psd, bap1, frame_bits,
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csnroffst + SNR_INC1, 0) >= 0) {
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csnroffst + SNR_INC1, 0) >= 0) {
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csnroffst += SNR_INC1;
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csnroffst += SNR_INC1;
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memcpy(bap, bap1, sizeof(bap1));
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memcpy(bap, bap1, sizeof(bap1));
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}
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}
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while ((csnroffst + 1) <= 63 &&
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while ((csnroffst + 1) <= 63 &&
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bit_alloc(s, bap1, encoded_exp, exp_strategy, frame_bits, csnroffst + 1, 0) >= 0) {
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bit_alloc(s, mask, psd, bap1, frame_bits, csnroffst + 1, 0) >= 0) {
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csnroffst++;
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csnroffst++;
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memcpy(bap, bap1, sizeof(bap1));
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memcpy(bap, bap1, sizeof(bap1));
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}
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}
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fsnroffst = 0;
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fsnroffst = 0;
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while ((fsnroffst + SNR_INC1) <= 15 &&
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while ((fsnroffst + SNR_INC1) <= 15 &&
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bit_alloc(s, bap1, encoded_exp, exp_strategy, frame_bits,
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bit_alloc(s, mask, psd, bap1, frame_bits,
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csnroffst, fsnroffst + SNR_INC1) >= 0) {
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csnroffst, fsnroffst + SNR_INC1) >= 0) {
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fsnroffst += SNR_INC1;
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fsnroffst += SNR_INC1;
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memcpy(bap, bap1, sizeof(bap1));
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memcpy(bap, bap1, sizeof(bap1));
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}
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}
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while ((fsnroffst + 1) <= 15 &&
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while ((fsnroffst + 1) <= 15 &&
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bit_alloc(s, bap1, encoded_exp, exp_strategy, frame_bits,
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bit_alloc(s, mask, psd, bap1, frame_bits,
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csnroffst, fsnroffst + 1) >= 0) {
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csnroffst, fsnroffst + 1) >= 0) {
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fsnroffst++;
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fsnroffst++;
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memcpy(bap, bap1, sizeof(bap1));
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memcpy(bap, bap1, sizeof(bap1));
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