Commit 08101e62 authored by Paul B Mahol's avatar Paul B Mahol

adpcm: improve smjpeg decoding

Previous version had significant artifacts.
Signed-off-by: 's avatarPaul B Mahol <onemda@gmail.com>
parent a373f352
......@@ -1136,16 +1136,26 @@ static int adpcm_decode_frame(AVCodecContext *avctx, void *data,
}
break;
case AV_CODEC_ID_ADPCM_IMA_AMV:
case AV_CODEC_ID_ADPCM_IMA_SMJPEG:
if (avctx->codec->id == AV_CODEC_ID_ADPCM_IMA_AMV) {
c->status[0].predictor = sign_extend(bytestream2_get_le16u(&gb), 16);
c->status[0].step_index = bytestream2_get_le16u(&gb);
bytestream2_skipu(&gb, 4);
} else {
if (c->status[0].step_index > 88u) {
av_log(avctx, AV_LOG_ERROR, "ERROR: step_index = %i\n",
c->status[0].step_index);
return AVERROR_INVALIDDATA;
}
for (n = nb_samples >> (1 - st); n > 0; n--) {
int v = bytestream2_get_byteu(&gb);
*samples++ = adpcm_ima_expand_nibble(&c->status[0], v >> 4, 3);
*samples++ = adpcm_ima_expand_nibble(&c->status[0], v & 0xf, 3);
}
break;
case AV_CODEC_ID_ADPCM_IMA_SMJPEG:
c->status[0].predictor = sign_extend(bytestream2_get_be16u(&gb), 16);
c->status[0].step_index = bytestream2_get_byteu(&gb);
bytestream2_skipu(&gb, 1);
}
if (c->status[0].step_index > 88u) {
av_log(avctx, AV_LOG_ERROR, "ERROR: step_index = %i\n",
c->status[0].step_index);
......@@ -1153,18 +1163,10 @@ static int adpcm_decode_frame(AVCodecContext *avctx, void *data,
}
for (n = nb_samples >> (1 - st); n > 0; n--) {
int hi, lo, v = bytestream2_get_byteu(&gb);
if (avctx->codec->id == AV_CODEC_ID_ADPCM_IMA_AMV) {
hi = v & 0x0F;
lo = v >> 4;
} else {
lo = v & 0x0F;
hi = v >> 4;
}
int v = bytestream2_get_byteu(&gb);
*samples++ = adpcm_ima_expand_nibble(&c->status[0], lo, 3);
*samples++ = adpcm_ima_expand_nibble(&c->status[0], hi, 3);
*samples++ = adpcm_ima_qt_expand_nibble(&c->status[0], v >> 4, 3);
*samples++ = adpcm_ima_qt_expand_nibble(&c->status[0], v & 0xf, 3);
}
break;
case AV_CODEC_ID_ADPCM_CT:
......
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