RepoMirrors
/
ffmpeg
mirror of https://git.ffmpeg.org/ffmpeg.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

avcodec/vc1: fix decoding of old WMV3 format 

The position of the second MV predicitor candidate is slightly different
for the old WMV3 format indicated by RES_RTM_FLAG. This patch fixes
decoding of niceday.wmv on the samples server.

Fixes: #6641

Signed-off-by: Jerome Borsboom <jerome.borsboom@carpalis.nl>
This commit is contained in:
Jerome Borsboom 2019-01-12 16:14:00 +01:00 committed by Carl Eugen Hoyos
parent 96740ec69f
commit b640227832
2 changed files with 4 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
libavcodec/vc1.c
View File

@ -379,11 +379,6 @@ int ff_vc1_decode_sequence_header(AVCodecContext *avctx, VC1Context *v, GetBitCo
} else {
v->res_rtm_flag = get_bits1(gb); //reserved
}
if (!v->res_rtm_flag) {
av_log(avctx, AV_LOG_ERROR,
"Old WMV3 version detected, some frames may be decoded incorrectly\n");
//return -1;
}
//TODO: figure out what they mean (always 0x402F)
if (!v->res_fasttx)
skip_bits(gb, 16);

5
libavcodec/vc1_pred.c
View File

@ -275,7 +275,10 @@ void ff_vc1_pred_mv(VC1Context *v, int n, int dmv_x, int dmv_y,
//in 4-MV mode different blocks have different B predictor position
switch (n) {
case 0:
off = (s->mb_x > 0) ? -1 : 1;
if (v->res_rtm_flag)
off = s->mb_x ? -1 : 1;
else
off = s->mb_x ? -1 : 2 * s->mb_width - wrap - 1;
break;
case 1:
off = (s->mb_x == (s->mb_width - 1)) ? -1 : 1;