[FFmpeg-cvslog] r13899 - in trunk/libavformat: isom.c mov.c

[Baptiste Coudurier]

Hi,

Michael Niedermayer wrote:
> On Mon, Jun 23, 2008 at 10:53:07AM +0200, Benoit Fouet wrote:
>> Benoit Fouet wrote:
>>> Baptiste Coudurier wrote:
>>>   
>>>> Hi,
>>>>
>>>> bcoudurier wrote:
>>>>
>>>>     
>>>>> [...]
>>>>>
>>>>>  static const MOVParseTableEntry mov_default_parse_table[] = {
>>>>> +{ MKTAG('a','v','s','s'), mov_read_extradata },
>>>>>  { MKTAG('c','o','6','4'), mov_read_stco },
>>>>>  { MKTAG('c','t','t','s'), mov_read_ctts }, /* composition time to sample */
>>>>>  { MKTAG('d','i','n','f'), mov_read_default },
>>>>>
>>>>>       
>>>> Btw this is really annoying to have to add specific atom parsing to
>>>> retrieve extradata, applications cannot decode file with lavf, even if
>>>> demuxer currently ouput correctly all samples.
>>>>
>>>> A generic way for exporting this is needed. Atm Im thinking of putting
>>>> everything after 'stsd' generic fields in extradata. What do you guys
>>>> think ?
>>>>
>>>>
>>>>     
>>> well, that will need some rework in decoders, but would save a lot of
>>> work in the demuxer
>>>
>>>   
>> well, on second thought... this will also break compatibility with other
>> containers
> 
> yes
> 
> 
>> , no ? and also break decoders people would have written using
>> lavf...
> 
> yes
> 
> it would also break stream copy
> 

Of course there are some things to change, to allow this, but definitely
this is the goal to achieve, I mean there is no use to be so correct and
generic when exporting samples, but not exporting extradata in a generic
way.

One solution Benoit suggested is to have a default case, and export
everything after stsd when atoms are not recognized, but this will
produce a different behaviour based on codecs and Im not sure this is
good for the API.

-- 
Baptiste COUDURIER                              GnuPG Key Id: 0x5C1ABAAA
Smartjog USA Inc.                                http://www.smartjog.com
Key fingerprint                 8D77134D20CC9220201FC5DB0AC9325C5C1ABAAA