Merge commit '242fc639' into release/2.4

* commit '242fc639':
  mtv: improve header check and avoid division by zero

Conflicts:
	libavformat/mtv.c

See: 8b9b6332Merged-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/mtv.c

@@ -112,7 +112,7 @@ static int mtv_read_header(AVFormatContext *s)
     mtv->audio_identifier  = avio_rl24(pb);
     mtv->audio_br          = avio_rl16(pb);
     mtv->img_colorfmt      = avio_rl24(pb);
-    mtv->img_bpp           = avio_r8(pb)>>3;
+    mtv->img_bpp           = avio_r8(pb);
     mtv->img_width         = avio_rl16(pb);
     mtv->img_height        = avio_rl16(pb);
     mtv->img_segment_size  = avio_rl16(pb);
@@ -128,17 +128,17 @@ static int mtv_read_header(AVFormatContext *s)
 
     /* Calculate width and height if missing from header */
 
-    if(!mtv->img_width && mtv->img_height)
-        mtv->img_width=mtv->img_segment_size / (mtv->img_bpp)
+    if (!mtv->img_width && mtv->img_height > 0 && mtv->img_bpp >= 8)
+        mtv->img_width=mtv->img_segment_size / (mtv->img_bpp>>3)
                         / mtv->img_height;
 
-    if(!mtv->img_height && mtv->img_width)
-        mtv->img_height=mtv->img_segment_size / (mtv->img_bpp)
+    if (!mtv->img_height && mtv->img_width > 0 && mtv->img_bpp >= 8)
+        mtv->img_height=mtv->img_segment_size / (mtv->img_bpp>>3)
                         / mtv->img_width;
 
     if(!mtv->img_height || !mtv->img_width || !mtv->img_segment_size){
         av_log(s, AV_LOG_ERROR, "width or height or segment_size is invalid and I cannot calculate them from other information\n");
-        return AVERROR(EINVAL);
+        return AVERROR_INVALIDDATA;
     }
 
     avio_skip(pb, 4);