[FFmpeg-devel] add HEVC codec into flv format

[Hendrik Leppkes]

On Sat, Jun 7, 2014 at 2:00 AM, compn <tempn at twmi.rr.com> wrote:
> On Fri, 6 Jun 2014 13:03:50 -0400
> "Ronald S. Bultje" <rsbultje at gmail.com> wrote:
>
>> On Fri, Jun 6, 2014 at 12:45 PM, compn <tempn at twmi.rr.com> wrote:
>> > On Wed, 4 Jun 2014 21:56:21 +0800
>> > Steven Liu <lingjiujianke at gmail.com> wrote:
>> >
>> > > +    FLV_CODECID_HEVC    = 10,
>> >
>> > ffmpeg has always supported broken or non-official hacks.
>>
>> You're confusing mplayer and ffmpeg here.
>
> DIVX isnt in the AVI / wav spec,
> http://wiki.multimedia.cx/index.php?title=AVI
> http://www.rfc-base.org/txt/rfc-2361.txt
>
> neither are the other 400+ codecs we've painstakingly compiled
> http://wiki.multimedia.cx/index.php?title=Category_talk:Video_FourCCs
> or the unregistered twoccs we've found:
> http://wiki.multimedia.cx/index.php?title=TwoCC
>
> so we (ffmpeg) either supports DIV3, DIVX, XVID and FMP4 along with all
> other 'non official' codec fourccs , or we dont.
>
> i dont see any difference between 3rd party codecs in flv or avi or mov.
> same thing happened with ogg and mkv. you cant block people from adding
> codecs (vorbis in avi), you can only try to mitigate the disaster
> (vorbis in avi) and decode existing samples.
>

There is a big difference between accepting unmistakable FourCCs with
32-bit of actual data to identify them, it being unlikely that those
FourCCs ever get re-used by something else for something entirely
different, and just using the next enumerated number in the flv spec
which is the obvious choice for re-use by Adobe when they extend the
spec to include a new format.

AVI/RIFF with its FourCC is designed to accept arbitrary data, as is
MKV - they all carry a proper field to identify the codec by its
FourCC.
FLV is not designed like this. It has to rely on a fixed definition of
the codecs, or everything falls apart.

- Hendrik