[FFmpeg-devel] [RFC] comment mpegvideo_split

[Baptiste Coudurier]

Michael Niedermayer wrote:
> On Thu, Apr 03, 2008 at 03:08:32PM +0200, Baptiste Coudurier wrote:
>> Hi,
>>
>> Michael Niedermayer wrote:
>>> On Wed, Mar 19, 2008 at 04:11:37PM +0100, Baptiste Coudurier wrote:
>>>> Baptiste Coudurier wrote:
>>>>> Michael Niedermayer wrote:
>>>>>> On Tue, Mar 18, 2008 at 01:16:34AM +0100, Baptiste Coudurier wrote:
>>>>>>> Hi,
>>>>>>>
>>>>>>> Currently, mpegvideo split function causes problems with containers
>>>>>>> setting AVFMT_GLOBAL_HEADER, mov and mp4 in particular, because
>>>>>>> MPEG-1/2 in those containers are to be muxed normally.
>>>>>>>
>>>>>>> I don't know any particular usage of the mpegvideo split function, so I
>>>>>>> tend to want to comment it, to finally fix this issue.
>>>>>>>
>>>>>>> Anyone see another better alternative ?
>>>>>> After a few more seconds :)
>>>>>> The muxers could just dump extradata for the case of mpeg1/2 before keyframes,
>>>>>> that should fix it i think. Its of course a little odd to first extract and
>>>>>> then put it back in the muxer.
>>>>>>
>>>>> Would the attached patch be ok ?
>>>>>
>>>> This one is more correct, messy though.
>>>>
>>>> [...]
>>>>  
>>>> +    if (dump_extradata) {
>>>> +        put_buffer(pb, trk->vosData, trk->vosLen);
>>>> +        size -= trk->vosLen;
>>>> +    }
>>>>      put_buffer(pb, pkt->data, size);
>>>>  
>>>>      put_flush_packet(pb);
>>> ok, its not beautifull but i dont know a better solution. Maybe some
>>> auto insertion of a bitstream filter, that could also be usefull to
>>> simplify other cases ...> > Anyway i think its better to commit this, we can always revert it if
>>> someone does find a better solution.
>>>
>> I was thinking about this other solution, and it seems to work, though
>> It acts a bit behind the user's back.
> 
> I wonder if this will work with -vcodec copy from nut.
> 

FYI:
ffmpeg -i <file.m2v> -vcodec copy test.nut does not work as is.

So I guess nut muxing suffers from the same problem when stream copying.

ffmpeg -i <file> -vcodec mpeg2video test.nut,
ffmpeg -i test.nut -vcodec copy test.mov works with the patch.

-- 
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