diff options
Diffstat (limited to 'libavcodec/mpegvideo_enc.c')
| -rw-r--r-- | libavcodec/mpegvideo_enc.c | 40 |
1 files changed, 38 insertions, 2 deletions
diff --git a/libavcodec/mpegvideo_enc.c b/libavcodec/mpegvideo_enc.c index a2061532ae..6fe34b57f8 100644 --- a/libavcodec/mpegvideo_enc.c +++ b/libavcodec/mpegvideo_enc.c @@ -4196,6 +4196,42 @@ STOP_TIMER("iterative search") return last_non_zero; } +/** + * Permute an 8x8 block according to permuatation. + * @param block the block which will be permuted according to + * the given permutation vector + * @param permutation the permutation vector + * @param last the last non zero coefficient in scantable order, used to + * speed the permutation up + * @param scantable the used scantable, this is only used to speed the + * permutation up, the block is not (inverse) permutated + * to scantable order! + */ +static void block_permute(int16_t *block, uint8_t *permutation, + const uint8_t *scantable, int last) +{ + int i; + int16_t temp[64]; + + if (last <= 0) + return; + //FIXME it is ok but not clean and might fail for some permutations + // if (permutation[1] == 1) + // return; + + for (i = 0; i <= last; i++) { + const int j = scantable[i]; + temp[j] = block[j]; + block[j] = 0; + } + + for (i = 0; i <= last; i++) { + const int j = scantable[i]; + const int perm_j = permutation[j]; + block[perm_j] = temp[j]; + } +} + int ff_dct_quantize_c(MpegEncContext *s, int16_t *block, int n, int qscale, int *overflow) @@ -4271,8 +4307,8 @@ int ff_dct_quantize_c(MpegEncContext *s, /* we need this permutation so that we correct the IDCT, we only permute the !=0 elements */ if (s->idsp.perm_type != FF_IDCT_PERM_NONE) - ff_block_permute(block, s->idsp.idct_permutation, - scantable, last_non_zero); + block_permute(block, s->idsp.idct_permutation, + scantable, last_non_zero); return last_non_zero; } |