[FFmpeg-devel] [PATCH v1] avformat/rtmpproto: support fourCcList property in enhanced rtmp

[Marton Balint]

On Wed, 23 Aug 2023, Martin Storsjö wrote:

> On Wed, 23 Aug 2023, Jean-Baptiste Kempf wrote:
>
>>  Hello,
>>
>>  On Mon, 21 Aug 2023, at 03:35, Steven Liu wrote:
>>>  Jean-Baptiste Kempf <jb at videolan.org> 于2023年8月20日周日 16:29写道：
>>>>
>>>>  Hello,
>>>  Hi
>>>>
>>>>  On Sun, 20 Aug 2023, at 06:10, Steven Liu wrote:
>>>> >  As the enhanced rtmp Extending NetConnection connect Command section
>>>> >  said, the rtmp should add a property named fourCcLive, but there 
>>>> >  should
>>>> >  only one codec can be set for the video stream in rtmp+flv, so user 
>>>> >  can
>>>> >  use the option rtmp_enhanced_flags to set the enhanced rtmp with av1,
>>>> >  hevc or vp9.
>>>>
>>>>  Technically, the protocol allows any type of FourCC, no?
>>>  The protocol should allows any type of FourCC, i saw there have three
>>>  codecs in the example["av01", "vp09", "hvc1"].
>>
>>  My question is then why have 0,1,2,3 and not a fourcc then? Or does this
>>  question make no sense on the protocol level?
>
> Put another way, why map a string to a number and back to a string - why not 
> just keep it a string throughout?

Agreed. Plus it is actually list, so you eventually you might want to 
support multiple fourcc-s by splitting the fourcc list. And the 
type is a strict array, so simply putting a string wihtout array length 
seems suspicious anyway.

Regards,
Marton