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| author | Mike Melanson <mike@multimedia.cx> | 2003-09-19 04:41:02 +0000 |
|---|---|---|
| committer | Mike Melanson <mike@multimedia.cx> | 2003-09-19 04:41:02 +0000 |
| commit | b10529b4c47b3435faa4be85f344cffcb5d30896 (patch) | |
| tree | d9d5ee9faf38540aadc2fff952d91d5e3afe3329 | |
| parent | 42e96409d3e9008cdb2516ff7ae2dcdd9f5a28d5 (diff) | |
| download | ffmpeg-b10529b4c47b3435faa4be85f344cffcb5d30896.tar.gz | |
fix Interplay DPCM (frames are intracoded, predictors do not carry
forward to next block, initial predictors go to the output)
Originally committed as revision 2294 to svn://svn.ffmpeg.org/ffmpeg/trunk
| -rw-r--r-- | libavcodec/dpcm.c | 30 |
1 files changed, 9 insertions, 21 deletions
diff --git a/libavcodec/dpcm.c b/libavcodec/dpcm.c index 958e46467d..ef4ccf8860 100644 --- a/libavcodec/dpcm.c +++ b/libavcodec/dpcm.c @@ -39,7 +39,6 @@ typedef struct DPCMContext { int channels; short roq_square_array[256]; - int last_delta[2]; } DPCMContext; #define SATURATE_S16(x) if (x < -32768) x = -32768; \ @@ -119,11 +118,9 @@ static int dpcm_decode_frame(AVCodecContext *avctx, { DPCMContext *s = avctx->priv_data; int in, out = 0; - int i; int predictor[2]; int channel_number = 0; short *output_samples = data; - int sequence_number; int shift[2]; unsigned char byte; short diff; @@ -152,21 +149,16 @@ static int dpcm_decode_frame(AVCodecContext *avctx, break; case CODEC_ID_INTERPLAY_DPCM: - in = 0; - sequence_number = LE_16(&buf[in]); - in += 6; /* skip over the stream mask and stream length */ - if (sequence_number == 1) { - predictor[0] = LE_16(&buf[in]); + in = 6; /* skip over the stream mask and stream length */ + predictor[0] = LE_16(&buf[in]); + in += 2; + SE_16BIT(predictor[0]) + output_samples[out++] = predictor[0]; + if (s->channels == 2) { + predictor[1] = LE_16(&buf[in]); in += 2; - SE_16BIT(predictor[0]) - if (s->channels == 2) { - predictor[1] = LE_16(&buf[in]); - SE_16BIT(predictor[1]) - in += 2; - } - } else { - for (i = 0; i < s->channels; i++) - predictor[i] = s->last_delta[i]; + SE_16BIT(predictor[1]) + output_samples[out++] = predictor[1]; } while (in < buf_size) { @@ -178,10 +170,6 @@ static int dpcm_decode_frame(AVCodecContext *avctx, channel_number ^= s->channels - 1; } - /* save predictors for next round */ - for (i = 0; i < s->channels; i++) - s->last_delta[i] = predictor[i]; - break; case CODEC_ID_XAN_DPCM: |