[Ffmpeg-devel] [PATCH] mov dnxhd muxing

[Baptiste Coudurier]

Michael Niedermayer wrote:
> Hi
> 
> On Fri, Mar 23, 2007 at 10:47:26AM +0100, Baptiste Coudurier wrote:
>> Michael Niedermayer wrote:
>>> Hi
>>>
>>> On Fri, Mar 23, 2007 at 02:54:20AM +0100, Baptiste Coudurier wrote:
>>>> Michael Niedermayer wrote:
>>>>> Hi
>>>>>
>>>>> On Fri, Mar 23, 2007 at 02:05:50AM +0100, Baptiste Coudurier wrote:
>>>>>> Michael Niedermayer wrote:
>>>>>>> Hi
>>>>>>>
>>>>>>> On Fri, Mar 23, 2007 at 01:05:20AM +0100, Baptiste Coudurier wrote:
>>>>>>>> Michael Niedermayer wrote:
>>>>>>>>> Hi
>>>>>>>>>
>>>>>>>>> On Thu, Mar 22, 2007 at 11:04:05PM +0100, Baptiste Coudurier wrote:
>>>>>>>>>> Hi
>>>>>>>>>>
>>>>>>>>>> Michael Niedermayer wrote:
>>>>>>>>>>> Hi
>>>>>>>>>>>
>>>>>>>>>>> On Thu, Mar 22, 2007 at 06:41:00PM +0100, Baptiste Coudurier wrote:
>>>>>>>>>>>> Hi
>>>>>>>>>>>>
>>>>>>>>>>>> Michael Niedermayer wrote:
>>>>>>>>>>>>> Hi
>>>>>>>>>>>>>
>>>>>>>>>>>>> On Thu, Mar 22, 2007 at 01:53:48PM +0100, Baptiste Coudurier wrote:
>>>>>>>>>>>>> [...]
>>>>>>>>>>>>>>>> Also, avid codecs need those specific mov atoms for some codecs ffmpeg
>>>>>>>>>>>>>>>> already supports, what would be the good way to write them ?
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Example: you can mux dv into mov using "AVdv" tag, then avid codecs will
>>>>>>>>>>>>>>>> decode stream perfectly if those atoms are present, though quicktime
>>>>>>>>>>>>>>>> wont decode it by default.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Quicktime has a native decoder for dv25 so use native one, but for dv50,
>>>>>>>>>>>>>>>>   there is no decoder. We can use Final cut one, which use his own
>>>>>>>>>>>>>>>> codec/own tag but only useable when fcp is installed, or Avid ones which
>>>>>>>>>>>>>>>> are freely available.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> So what muxing by default, and how to switch ? codec_tag ("stsd" tag) is
>>>>>>>>>>>>>>>> a solution, but people will have to know which tag to use.
>>>>>>>>>>>>>>> i dont think codec_tag should be (mis)used for this, but rather a new muxer
>>>>>>>>>>>>>>> similar to the one for psp should be added to movenc.c
>>>>>>>>>>>> Can you explain why you think that is "misusing" ? Remember that
>>>>>>>>>>> because the value of codec_tag does not depend on the existence of these
>>>>>>>>>>> specific atoms, a specific codec_tag also doesnt require a specific
>>>>>>>>>>> set of these atoms just try mp4v and psp vs. mp4
>>>>>>>>>> I am talking about existence of these atoms because of the value of
>>>>>>>>>> codec_tag, and that is correct.
>>>>>>>>>>
>>>>>>>>>>>> quicktime pass whole stsd atom to decoders, and those atoms are
>>>>>>>>>>>> contained IN stsd atom, so you cannot decorelate them.
>>>>>>>>>>> well you dont pass the whole atoms and you didnt propose to pass them
>>>>>>>>>>> so thats unrelated ...
>>>>>>>>>> existence of these specific atoms depends on codec_tag.
>>>>>>>>> huh? movenc.c does not contain code which writes them depending on codec_tag
>>>>>>>> huh, that's what Im willing to do and fighting for, you are against it,
>>>>>>>> Im proposing another solution, you are against it, you propose another
>>>>>>>> muxer, Im against it, I think we are having a fair discussion here.
>>>>>>>> I want to write those atoms if tag is AVdn or AVdv or ....
>>>>>>> why not write them if codec_id==DVVIDEO ?
>>>>>> I asked that in the first mail :(
>>>>> you asked about using codec_tag not codec_id theres a difference
>>>>> codec_tag is wrong codec_id is fine
>>>>> but its not clear yet to me if a test based on codec_id is possible
>>>>> its not clear from what you write 
>>>> Damn, that is not possible. So since my opinion does have any weigth, I
>>>> would like you to give me a solution to be able to create two files with
>>>> DVVIDEO as codec_id, pix_fmt as PIX_FMT_422P and 720x576 res, one will
>>>> be correctly played by avid codecs and one by Final cut pro. For avid
>>>> they must have "AVdv" tag and avid specific atoms, for Final Cut they
>>>> must have "dv5p" tag.
> 
> have you tried "dv5p" tag with avid specific atoms? does fcp play that?

Those atoms are unneeded with "dv5p", it would be stupid to write them.

>>> how does fcp & avid play dv from a camera? if theres no common format both
>>> support?
>> Quicktime has no dv50 native codec, while it has dv25.
>>
>> Now I need to ingest my mpeg2 422 into avid and fcp so I transcode to
>> dv50 in mov with ffmpeg, and that does not work with avid atm, avid file
>> is missing mandatory atoms to be decoded, I want to add that feature.
> 
> i dont belive that there is no other codec and container which can be
> used to import video from ffmpeg into avid, if there where none, avid
> would be unuseable ...
> 
> 
> heres a list if solutions in order of preferance (more prefered first)
> * dont support muxing DV in MOV

Not an option, it works perfectly.

> * dont support AVID specific hacks for DV in MOV

Not an option, I don't see any good reason to not support muxing files
for AVID systems.

> * support AVID specific hacks in MOV through a dummy muxer like for psp

That is an ugly hack.

According to new policy, can you please supply me a full svn dump ?
Thanks.

-- 
Baptiste COUDURIER                              GnuPG Key Id: 0x5C1ABAAA
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