diff options
| -rw-r--r-- | libavcodec/ac3enc.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/libavcodec/ac3enc.c b/libavcodec/ac3enc.c index cc5232b8a1..2bfb44ecce 100644 --- a/libavcodec/ac3enc.c +++ b/libavcodec/ac3enc.c @@ -1028,10 +1028,18 @@ static int bit_alloc(AC3EncodeContext *s, mant_cnt[1] = mant_cnt[2] = 2; mant_cnt[4] = 1; for (ch = 0; ch < s->channels; ch++) { + /* Currently the only bit allocation parameters which vary across + blocks within a frame are the exponent values. We can take + advantage of that by reusing the bit allocation pointers + whenever we reuse exponents. */ + if (block->exp_strategy[ch] == EXP_REUSE) { + memcpy(block->bap[ch], s->blocks[blk-1].bap[ch], AC3_MAX_COEFS); + } else { ff_ac3_bit_alloc_calc_bap(block->mask[ch], block->psd[ch], 0, s->nb_coefs[ch], snr_offset, s->bit_alloc.floor, ff_ac3_bap_tab, block->bap[ch]); + } mantissa_bits += compute_mantissa_size(mant_cnt, block->bap[ch], s->nb_coefs[ch]); } mantissa_bits += compute_mantissa_size_final(mant_cnt); |