[FFmpeg-soc] [Patch]Mxf muxer 0.0.1

[Baptiste Coudurier]

Hi,

Michael Niedermayer wrote:
> On Fri, Aug 15, 2008 at 01:03:52AM +0800, zhentan feng wrote:
>> Hi
>>
>> 2008/8/14 Michael Niedermayer <michaelni at gmx.at>
>>
>>> On Thu, Aug 14, 2008 at 11:41:01AM +0800, zhentan feng wrote:
> [...]
>
>>>>>> +};
>>>>> duplicate
>>>>>
>>>> I tried to extract this code ,however, we muxing by CodecID type to get
>>> UL,
>>>> but one CodecID have different ULs, such as CODEC_ID_PCM_S16LE.
>>>>
>>>> so when checking each item in mxf_essence_container_uls for streams to
>>> build
>>>> essence container references, we can not decide which ul to use only by
>>>> CodecID type.
>>>> But we actually know which type we should mux, so just write what will be
>>>> muxed type in the table.
>>> no reason not the share the tables, either CODEC_ID_PCM_S16LE must be
>>> special
>>> handled or the UL used for muxing can be the first CODEC_ID_PCM_S16LE in
>>> the
>>> table.
>>>
>> hmm, to get the ul when muxing, i think it is not enough only by CodecID
>> type.
>> Is it necessary to add some flag in the table( or get information from some
>> api in FFmpeg) to distinguish one CodecID type having different uls?
> 
> Either
> A. MXF supports generic 16bit PCM, in which case it has one (or more)
>    identifers for it and any of them can be used at will
> or
> B. MXF does not support generic 16bit PCM but supports just 16bit PCM with
>    a finite set of fixed samplerates/ channels in which case a different
>    identifer might need to be choosen for each sample rate or channel count.
>    in that case a simple
>    if(codec_id == CODEC_ID_PCM_S16LE && sample_rate==123) write(aaaa); can
>    be used.
> 

It depends on the mapping used, here to wrap WAV/AES3 essence there is a
spec, I already told zhentan to follow the spec.

For now we are using WAV/AES3 specs, so put this value at the top if you
want it to be picked.

The other codecs uls are for D-10 mapping, where the UL differs and some
specific code is done in demuxer to demux this, until a bitstream filter
or decoder is written.

[...]

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