diff options
author | Paul B Mahol <onemda@gmail.com> | 2019-04-10 13:10:09 +0300 |
---|---|---|
committer | Paul B Mahol <onemda@gmail.com> | 2019-04-11 12:58:34 +0300 |
commit | d0f24df648f46e4c9a385e12a057fbade21427db (patch) | |
tree | f1caceb1d36beac9e486d92f928d87adc8ecee77 /libavcodec/adpcm.c | |
parent | 7be8f7ac8143f4ae144c4951ddc5d42d466a9e23 (diff) |
avcodec: add ADPCM AGM decoder
Diffstat (limited to 'libavcodec/adpcm.c')
-rw-r--r-- | libavcodec/adpcm.c | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/libavcodec/adpcm.c b/libavcodec/adpcm.c index aa9c7c5c4f..ede0130bf1 100644 --- a/libavcodec/adpcm.c +++ b/libavcodec/adpcm.c @@ -177,6 +177,50 @@ static av_cold int adpcm_decode_init(AVCodecContext * avctx) return 0; } +static inline int16_t adpcm_agm_expand_nibble(ADPCMChannelStatus *c, int8_t nibble) +{ + int delta, pred, step, add; + + pred = c->predictor; + delta = nibble & 7; + step = c->step; + add = (delta * 2 + 1) * step; + if (add < 0) + add = add + 7; + + if ((nibble & 8) == 0) + pred = av_clip(pred + (add >> 3), -32767, 32767); + else + pred = av_clip(pred - (add >> 3), -32767, 32767); + + switch (delta) { + case 7: + step *= 0x99; + break; + case 6: + c->step = av_clip(c->step * 2, 127, 24576); + c->predictor = pred; + return pred; + case 5: + step *= 0x66; + break; + case 4: + step *= 0x4d; + break; + default: + step *= 0x39; + break; + } + + if (step < 0) + step += 0x3f; + + c->step = step >> 6; + c->step = av_clip(c->step, 127, 24576); + c->predictor = pred; + return pred; +} + static inline int16_t adpcm_ima_expand_nibble(ADPCMChannelStatus *c, int8_t nibble, int shift) { int step_index; @@ -549,6 +593,7 @@ static int get_nb_samples(AVCodecContext *avctx, GetByteContext *gb, header_size = 0; switch (avctx->codec->id) { case AV_CODEC_ID_ADPCM_4XM: + case AV_CODEC_ID_ADPCM_AGM: case AV_CODEC_ID_ADPCM_IMA_DAT4: case AV_CODEC_ID_ADPCM_IMA_ISS: header_size = 4 * ch; break; case AV_CODEC_ID_ADPCM_IMA_AMV: header_size = 8; break; @@ -863,6 +908,18 @@ static int adpcm_decode_frame(AVCodecContext *avctx, void *data, } } break; + case AV_CODEC_ID_ADPCM_AGM: + for (i = 0; i < avctx->channels; i++) + c->status[i].predictor = sign_extend(bytestream2_get_le16u(&gb), 16); + for (i = 0; i < avctx->channels; i++) + c->status[i].step = sign_extend(bytestream2_get_le16u(&gb), 16); + + for (n = 0; n < nb_samples >> (1 - st); n++) { + int v = bytestream2_get_byteu(&gb); + *samples++ = adpcm_agm_expand_nibble(&c->status[0], v & 0xF); + *samples++ = adpcm_agm_expand_nibble(&c->status[st], v >> 4 ); + } + break; case AV_CODEC_ID_ADPCM_MS: { int block_predictor; @@ -1729,6 +1786,7 @@ AVCodec ff_ ## name_ ## _decoder = { \ /* Note: Do not forget to add new entries to the Makefile as well. */ ADPCM_DECODER(AV_CODEC_ID_ADPCM_4XM, sample_fmts_s16p, adpcm_4xm, "ADPCM 4X Movie"); ADPCM_DECODER(AV_CODEC_ID_ADPCM_AFC, sample_fmts_s16p, adpcm_afc, "ADPCM Nintendo Gamecube AFC"); +ADPCM_DECODER(AV_CODEC_ID_ADPCM_AGM, sample_fmts_s16, adpcm_agm, "ADPCM AmuseGraphics Movie"); ADPCM_DECODER(AV_CODEC_ID_ADPCM_AICA, sample_fmts_s16p, adpcm_aica, "ADPCM Yamaha AICA"); ADPCM_DECODER(AV_CODEC_ID_ADPCM_CT, sample_fmts_s16, adpcm_ct, "ADPCM Creative Technology"); ADPCM_DECODER(AV_CODEC_ID_ADPCM_DTK, sample_fmts_s16p, adpcm_dtk, "ADPCM Nintendo Gamecube DTK"); |