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authorMike Melanson <mike@multimedia.cx>2003-09-19 04:41:02 +0000
committerMike Melanson <mike@multimedia.cx>2003-09-19 04:41:02 +0000
commitb10529b4c47b3435faa4be85f344cffcb5d30896 (patch)
treed9d5ee9faf38540aadc2fff952d91d5e3afe3329 /libavcodec/dpcm.c
parent42e96409d3e9008cdb2516ff7ae2dcdd9f5a28d5 (diff)
downloadffmpeg-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
Diffstat (limited to 'libavcodec/dpcm.c')
-rw-r--r--libavcodec/dpcm.c30
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: