diff options
Diffstat (limited to 'libavcodec')
| -rw-r--r-- | libavcodec/aac.h | 3 | ||||
| -rw-r--r-- | libavcodec/aacenc.c | 17 |
2 files changed, 17 insertions, 3 deletions
diff --git a/libavcodec/aac.h b/libavcodec/aac.h index b25b40c9c6..2701386376 100644 --- a/libavcodec/aac.h +++ b/libavcodec/aac.h @@ -141,6 +141,9 @@ typedef struct PredictorState { #define SCALE_MAX_DIFF 60 ///< maximum scalefactor difference allowed by standard #define SCALE_DIFF_ZERO 60 ///< codebook index corresponding to zero scalefactor indices difference +#define NOISE_PRE 256 ///< preamble for NOISE_BT, put in bitstream with the first noise band +#define NOISE_PRE_BITS 9 ///< length of preamble + /** * Long Term Prediction */ diff --git a/libavcodec/aacenc.c b/libavcodec/aacenc.c index 7015a2789c..5288afb4a2 100644 --- a/libavcodec/aacenc.c +++ b/libavcodec/aacenc.c @@ -388,15 +388,26 @@ static void encode_band_info(AACEncContext *s, SingleChannelElement *sce) static void encode_scale_factors(AVCodecContext *avctx, AACEncContext *s, SingleChannelElement *sce) { - int off = sce->sf_idx[0], diff; + int diff, off_sf = sce->sf_idx[0], off_pns = sce->sf_idx[0]; + int noise_flag = 1; int i, w; for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) { for (i = 0; i < sce->ics.max_sfb; i++) { if (!sce->zeroes[w*16 + i]) { - diff = sce->sf_idx[w*16 + i] - off + SCALE_DIFF_ZERO; + if (sce->band_type[w*16 + i] == NOISE_BT) { + diff = sce->sf_idx[w*16 + i] - off_pns; + off_pns = sce->sf_idx[w*16 + i]; + if (noise_flag-- > 0) { + put_bits(&s->pb, NOISE_PRE_BITS, diff + NOISE_PRE); + continue; + } + } else { + diff = sce->sf_idx[w*16 + i] - off_sf; + off_sf = sce->sf_idx[w*16 + i]; + } + diff += SCALE_DIFF_ZERO; av_assert0(diff >= 0 && diff <= 120); - off = sce->sf_idx[w*16 + i]; put_bits(&s->pb, ff_aac_scalefactor_bits[diff], ff_aac_scalefactor_code[diff]); } } |