[FFmpeg-cvslog] r19275 - trunk/libavformat/id3v2.c

[Michael Niedermayer]

On Mon, Jun 29, 2009 at 05:03:26PM +0530, Jai Menon wrote:
> On Mon, Jun 29, 2009 at 2:32 PM, Jai Menon<jmenon86 at gmail.com> wrote:
> > On Fri, Jun 26, 2009 at 12:56 AM, michael<subversion at mplayerhq.hu> wrote:
> >> Author: michael
> >> Date: Thu Jun 25 21:26:39 2009
> >> New Revision: 19275
> >>
> >> Log:
> >> Fix id3v2.3/4 tag size parsing.
> >> Fixes issue1106
> >>
> >> Modified:
> >> ? trunk/libavformat/id3v2.c
> >>
> >> Modified: trunk/libavformat/id3v2.c
> >> ==============================================================================
> >> --- trunk/libavformat/id3v2.c ? Thu Jun 25 21:10:27 2009 ? ? ? ?(r19274)
> >> +++ trunk/libavformat/id3v2.c ? Thu Jun 25 21:26:39 2009 ? ? ? ?(r19275)
> >> @@ -155,7 +155,7 @@ void ff_id3v2_parse(AVFormatContext *s,
> >> ? ? while (len >= taghdrlen) {
> >> ? ? ? ? if (isv34) {
> >> ? ? ? ? ? ? tag ?= get_be32(s->pb);
> >> - ? ? ? ? ? ?tlen = get_size(s->pb, 4);
> >> + ? ? ? ? ? ?tlen = get_be32(s->pb);
> >
> > About this, the spec at [1] seems to suggest that :
> >
> > "The ID3v2 tag size is stored as a 32 bit synchsafe integer (section
> > ? 6.2), making a total of 28 effective bits (representing up to 256MB)"
> 
> Sorry, wrong citation, here is the correct one :
> 
>    The frame ID is followed by a size descriptor containing the size of
>    the data in the final frame, after encryption, compression and
>    unsynchronisation. The size is excluding the frame header ('total
>    frame size' - 10 bytes) and stored as a 32 bit synchsafe integer.
> 
> If we go by this, then apic frame size in those samples (issue 1106
> and 1202) is invalid and maybe should be dealt as a special case. I'm
> not quite sure, thought you might have insights on this.

iam not quite sure either but i did understand the i3v2.2/3 specs as not
doing synchsafing on these fields. I missed that id3v2.4 does as you quote

lets see if this now works or if some files turn up that still fail ...

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Many things microsoft did are stupid, but not doing something just because
microsoft did it is even more stupid. If everything ms did were stupid they
would be bankrupt already.
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