[Ffmpeg-devel] [PATCH] mov dnxhd muxing

[Baptiste Coudurier]

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.

Another case, for D-10/IMX I need to use "mx5p" as tag and codec_id is
MPEG2VIDEO, and I need to put 576 as height while bitstream height is
608, I want also my files to be played by avid codecs with "AVmp".
I can also use codec_id MPEG2VIDEO in my files with "mpeg" tag with my
playout server without any problem,

I need a solution, and adding special muxers for those cases are not the
simplest nor the cleanest solution, what would it be ?

[...]

-- 
Baptiste COUDURIER                              GnuPG Key Id: 0x5C1ABAAA
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