avcodec/shorten: properly handle bitshift > 31

Signed-off-by: Paul B Mahol <onemda@gmail.com>
This commit is contained in:
Paul B Mahol 2016-04-11 13:06:10 +02:00
parent 15fa01786c
commit b62ed56e25

View File

@ -164,9 +164,13 @@ static void fix_bitshift(ShortenContext *s, int32_t *buffer)
{
int i;
if (s->bitshift != 0)
if (s->bitshift == 32) {
for (i = 0; i < s->blocksize; i++)
buffer[i] = 0;
} else if (s->bitshift != 0) {
for (i = 0; i < s->blocksize; i++)
buffer[i] <<= s->bitshift;
}
}
static int init_offset(ShortenContext *s)
@ -602,7 +606,7 @@ static int shorten_decode_frame(AVCodecContext *avctx, void *data,
break;
case FN_BITSHIFT: {
unsigned bitshift = get_ur_golomb_shorten(&s->gb, BITSHIFTSIZE);
if (bitshift > 31) {
if (bitshift > 32) {
av_log(avctx, AV_LOG_ERROR, "bitshift %d is invalid\n",
bitshift);
return AVERROR_INVALIDDATA;
@ -680,7 +684,7 @@ static int shorten_decode_frame(AVCodecContext *avctx, void *data,
if (s->version < 2)
s->offset[channel][s->nmean - 1] = sum / s->blocksize;
else
s->offset[channel][s->nmean - 1] = (sum / s->blocksize) << s->bitshift;
s->offset[channel][s->nmean - 1] = s->bitshift == 32 ? 0 : (sum / s->blocksize) << s->bitshift;
}
/* copy wrap samples for use with next block */