[FFmpeg-devel] HEVC decoder for Raspberry Pi

[John Cox]

Hi

>Hi
>
>On Tue, Nov 13, 2018 at 03:52:18PM +0000, John Cox wrote:
>> Hi
>> 
>> I have been developing a hevc decoder for Raspberry Pi for some time
>> now. As active development has now pretty much ceased and the code is
>> believed stable it seems a good time to try presenting it to the group.
>> 
>> You can find the current code on branch test/4.1.0/rpi_main in repo
>> https://github.com/jc-kynesim/rpi-ffmpeg.git. It is based off tag n4.1
>> so if you diff it against n4.1 you should get a patch.
>> 
>> This code has been in use by the Raspberry Pi version of Kodi for over
>> two years now.
>> 
>> If you think it would be a good idea to add this to the main ffmpeg
>> distribution then I am willing to put reasonable effort into beating it
>> into an appropriate shape.
>> 
>> If not then it contains a reasonable number of ARM asm functions and
>> other code that you might like to take/adapt for the current decoder.
>> 
>> You will find the config scripts I have been using and a few notes in
>> the pi-util directory if you wish to try building it for yourself.
>> 
>> Just in case it isn't obvious: this will only run on a Pi.  Slightly
>> less obviously you need a Pi2 or better as the Pi0 & Pi1 don't have neon
>> and are just too slow anyway.
>
>others may have other oppinions, but i think optimized code in FFmpeg
>for Pi would be a good idea.
>How to integrate this best though i do not know. And i cant know as
>i have just quickly scrolled over the changes not really looked in detail

Well if you want help with understanding what I've done feel free to
email me and I'll do my best to explain.

>But its certainly better to have hw optimizations in main git and
>not have a seperate repository that needs to be maintained seperatly
>for each platform ... and that the user has to find also ... and then
>3rd party apps could have even more issues here  if they wanted to use
>optimized libs ...

As I said I'm happy to put in reasonable amounts of work to make this
happen. If we do want to go ahead then may I suggest that the most
efficient way of proceeding would be that I take advice from one
experienced person who understands the current hevc code (Michael?) by
email until the work is mostly done and then return to the list for
final polish?

Regards

JC