Fixes issue624.
Originally committed as revision 15416 to svn://svn.ffmpeg.org/ffmpeg/trunk
static int is_intra_more_likely(MpegEncContext *s){
int is_intra_likely, i, j, undamaged_count, skip_amount, mb_x, mb_y;
- if(s->last_picture_ptr==NULL) return 1; //no previous frame available -> use spatial prediction
+ if(!s->last_picture_ptr || !s->last_picture_ptr->data[0]) return 1; //no previous frame available -> use spatial prediction
undamaged_count=0;
for(i=0; i<s->mb_num; i++){