[FFmpeg-devel] [PATCH] libavformat/flvdec: add HEVC demuxing support

[Steven Liu]

在 2021年7月26日星期一，Gyan Doshi <ffmpeg at gyani.pro> 写道：

>
>
> On 2021-07-26 19:49, Steven Liu wrote:
>
>> 在 2021年7月26日星期一，Gyan Doshi <ffmpeg at gyani.pro> 写道：
>>
>>
>>> On 2021-07-26 16:39, Steven Liu wrote:
>>>
>>> 2021年7月26日 下午6:57，Gyan Doshi <ffmpeg at gyani.pro> 写道：
>>>>
>>>>> Are you referring to the choice of FLV_CODECID values?
>>>>>
>>>>> Not only, you can find whole history on:
>>>>
>>>> https://lists.ffmpeg.org/pipermail/ffmpeg-devel/
>>>> https://trac.ffmpeg.org/ticket/6389
>>>> https://trac.ffmpeg.org/ticket/3581
>>>>
>>>> try play this sample in ticket
>>> The objections mainly center on compliance with Adobe's spec which is a
>>> concern when muxing.
>>>
>>> no not only muxing, it’s format spec, and no documentation said which
>>>
>> codec id is hevc. 10?11?12?13?14?15? How do you make sure which one is
>> hevc
>> from users flv? This is very unreasonable.
>>
>
> By making it a user option: ffmpeg -f flv -hevc_id 12 -i rtmp://...

i do not think this can play all flv from other muxing, just private
demuxing, so why add it in ffmpeg? It is your private format, it can not
play all flv with hevc.

>
>
> This patch is only concerned with demuxing, so we are only talking about
>>> files generated by others.
>>>
>>> The only technical issue is the assignment of FLV_CODECID which can be
>>> mitigated by letting the user specify it at runtime. So muxers which use
>>> different values can be accommodated.
>>>
>>> About other codecs, HW enc/dec for HEVC are widely available, not so for
>>> VVC, AV1, VP? ..etc, so the slippery slope is not a concern in the near
>>> or
>>> mid-term.
>>>
>>   opus? HEVC is just one codec today, what about tomorrow? This is why so
>> many people objection about this kind of patchset.
>>
>
> The slippery slope is theoretical. It will only come up when *other* FLV
> producers start muxing new codecs and *other* consumers start accepting
> such files.
> Without that co-ordination and certain amount of market buy-in, this is
> not a concern.

 Of course, We are using now, ok?

>
> Regards,
> Gyan
>
>
>
>> Regards,
>>> Gyan
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