[MPlayer-dev-eng] another libavcodec bug ...

[Michael Niedermayer]

Hi

On Monday 31 December 2001 15:27, Michael Niedermayer wrote:
> Hi
>
> i just found a file which shows some artefacts on the left edge of the
> image mostly on the bottom 50% (occures several times in the first 2min)
> divx4 & divx3 are ok
>
> iam uploading it to incoming/left_edge_artifacts_in_ffmpeg.avi
[...]
fixed :) but the fix doesnt make much sense to me :(
the fix simply deactivates the ac prediction for the leftmost middle blocks 1 
lumi 2 chromi
perhaps someone knows whats broken...

----hand written diff from libavcodec/h263.c----
    }
    ac_val += ((y) * wrap + (x)) * 16;
    ac_val1 = ac_val;
-    if (s->ac_pred) {
+    if (s->ac_pred 
+    	&& !(x==1 && y==s->mb_height  +1 && n==0) 
+	&& !(x==1 && y==s->mb_height/2+1 && n>=4)) {
        if (dir == 0 ) {
            /* left prediction */
            ac_val -= 16;
----end----

Michael