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ffv1dec: Require a valid keyframe for decoding non keyframes.

Before this the context could become inconsistent, this lead to a null ptr
dereference.

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Michael Niedermayer 2012-04-22 13:56:07 +02:00
parent 23a6e4749f
commit abec6549ae

View File

@ -193,6 +193,7 @@ typedef struct FFV1Context{
int gob_count;
int packed_at_lsb;
int ec;
int key_frame_ok;
int quant_table_count;
@ -1945,11 +1946,17 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPac
p->pict_type= AV_PICTURE_TYPE_I; //FIXME I vs. P
if(get_rac(c, &keystate)){
p->key_frame= 1;
f->key_frame_ok = 0;
if(read_header(f) < 0)
return -1;
if(init_slices_state(f) < 0)
return -1;
f->key_frame_ok = 1;
}else{
if (!f->key_frame_ok) {
av_log(avctx, AV_LOG_ERROR, "Cant decode non keyframe without valid keyframe\n");
return AVERROR_INVALIDDATA;
}
p->key_frame= 0;
}
if(f->ac>1){