[FFmpeg-devel] [PATCH] stricter dnxhd test

[Reimar Döffinger]

On Mon, Sep 14, 2009 at 02:00:10PM -0700, Baptiste Coudurier wrote:
> On 09/14/2009 01:54 PM, Reimar D?ffinger wrote:
> > I believe this to be correct in so far as our decoder should fail for
> > any formats this rejects.
> > Unfortunately I was not able to find any samples for raw DNxHD (I thought
> > there were some in the samples archive, but I didn't find any), so it is
> > untested...
> 
> We have a dnxhd encoder :)

Not really a good substitute for real-world data, not to mention that I
just haven't had the motivation to figure out how to use it (it's yet
another format where you have to get everything right, size, frame rate,
..., isn't it?). I checked if "make test" is so kind to leave a file
behind, but it seems it is not hooked up to regression tests? Why?

> > Index: libavformat/raw.c
> > ===================================================================
> > --- libavformat/raw.c   (revision 19844)
> > +++ libavformat/raw.c   (working copy)
> > @@ -558,10 +558,17 @@
> >   static int dnxhd_probe(AVProbeData *p)
> >   {
> >       static const uint8_t header[] = {0x00,0x00,0x02,0x80,0x01};
> > -    if (!memcmp(p->buf, header, 5))
> > -        return AVPROBE_SCORE_MAX;
> > -    else
> > +    int w, h, compression_id;
> > +    if (memcmp(p->buf, header, 5))
> >           return 0;
> > +    h = AV_RB16(p->buf + 0x18);
> > +    w = AV_RB16(p->buf + 0x1a);
> > +    if (!w || !h)
> > +        return 0;
> > +    compression_id = AV_RB32(p->buf + 0x28);
> > +    if (compression_id<  1237 || compression_id>  1253)
> > +        return 0;
> > +    return AVPROBE_SCORE_MAX;
> 
> Missing p->buf_size check ? AVPROBE_PADDING_SIZE is 32.

Yes, it's too late already, I remembered to do it when I started coding
the checks, by the time I finished I had forgotten :-)

Index: libavformat/raw.c
===================================================================
--- libavformat/raw.c   (revision 19844)
+++ libavformat/raw.c   (working copy)
@@ -558,10 +558,19 @@
 static int dnxhd_probe(AVProbeData *p)
 {
     static const uint8_t header[] = {0x00,0x00,0x02,0x80,0x01};
-    if (!memcmp(p->buf, header, 5))
-        return AVPROBE_SCORE_MAX;
-    else
+    int w, h, compression_id;
+    if (p->buf_size < 0x2c)
         return 0;
+    if (memcmp(p->buf, header, 5))
+        return 0;
+    h = AV_RB16(p->buf + 0x18);
+    w = AV_RB16(p->buf + 0x1a);
+    if (!w || !h)
+        return 0;
+    compression_id = AV_RB32(p->buf + 0x28);
+    if (compression_id < 1237 || compression_id > 1253)
+        return 0;
+    return AVPROBE_SCORE_MAX;
 }
 #endif