[Ffmpeg-devel] [PATCH] mov dnxhd muxing

Baptiste Coudurier baptiste.coudurier
Fri Mar 23 10:47:26 CET 2007


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.
> 
> 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.

-- 
Baptiste COUDURIER                              GnuPG Key Id: 0x5C1ABAAA
SMARTJOG S.A.                                    http://www.smartjog.com
Key fingerprint                 8D77134D20CC9220201FC5DB0AC9325C5C1ABAAA
Phone: +33 1 49966312




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