[FFmpeg-devel] PacketVideo PVPlayer lockup

Baptiste Coudurier baptiste.coudurier
Tue Oct 16 18:43:58 CEST 2007


Hi,

M?ns Rullg?rd wrote:
> Larry Reisler wrote:
> 
>> We have noted that certain versions of the PacketVideo PVPlayer on the Symbian
>> handset lock up when they receive a .3gp file generated by ffmpeg (in fact,
>> they lock up the whole phone).
> 
> That's not really our problem, is it?  You should file a bug report to
> whoever wrote that app.

Indeed PVPlayer crash is none of our business.

>> After doing a comparison with other encoders (which generated playable files),
>> it became clear that the major difference was that the other encoders either
>> generated a udta block with data, or didn?t generate it at all.  It seems like
>> the problem is that ffmpeg will generate a ?udta? tag even if there is not data
>> in the block.  It seems like PacketVideo doesn?t like this.
> 
> What do the specs say about this block?  Is a zero-sized udta block legal?
> If not, we should of course fix FFmpeg so as not to create such files.
> That said, the player is still broken if it crashes on invalid data.
> 

3GP specs defines it, and it is allowed to be empty, it has size of 8
actually, quoting TS 26.244:

"Within the user-data box, there may reside sub-boxes that contain asset
meta-data, taken from the list of boxes in table 8.1 through 8.10 below
(zero or more sub-boxes of each kind, zero or one for each language or
role of location information). Each of the sub-boxes conforms to the
definition of a "full box" as specified in [7] (hence the 'Version' and
'Flags' fields)."

I disabled writing of "udta" though, because what we could write in any
way is not conforming to specs.

So files should should play in PVPlayer now.

-- 
Baptiste COUDURIER                              GnuPG Key Id: 0x5C1ABAAA
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