Buildbot compatibility

[deltabeard]

An issue was raised in libretro/libretro-super#691 with regards to getting libretro-mpv added to the buildbot.

[andres-asm]

If we work on the builtin core instead of the standalone one, it can be arranged.
I have been testing it, other than no audio it's a lot better than the ffmpeg core

Are you still willing to improve the core? I ask because I haven't seen you around in a while.

[deltabeard]

Hi, it’s been a while.

I stopped working on libretro-mpv because of the audio issues that I was getting with the core. The plan was to add an audio callback driver to mpv which would pass audio samples to the libretro frontend. This would allow the libretro frontend to control the audio settings, such as audio driver and pause/play. My work in progress commit may be found here: mpv-player/mpv#5566. The issue with this however, is that the audio begins to stutter when using this audio callback. I was not sure how to resolve this issue, so I lost motivation and decided to work on other projects.

Without using the audio callback driver, the audio plays fine but the libretro frontend is not able to pause the audio. So the audio callback is required.

One advantage to using libretro-mpv is that it can use hardware accelerated decoding if it available on the running platform. However, playing videos in mpv using software rendering works well. So I wonder if there is a bug in the current libretro-ffmpeg core that is slowing video playback down rather than the lack of hardware acceleration support? It may be worth looking at https://github.com/katajakasa/SDL_kitchensink for a reference implementation for a ffmpeg core. If the performance of SDL_kitchensink is comparable to mpv, it may be worth looking at that implementation rather than using libmpv as some sort of middleman for playing video.

So there are my thoughts currently. I don’t think I’ll be working on libretro-mpv for the foreseeable future because of that audio issue. But it would be great if someone else could have a go at resolving that issue.

Kind Regards,
Mahyar

[ofry]

This PR could add audio callback:

mpv-player/mpv#5566

Could anyone fix code style issues in this PR?

[deltabeard]

This PR could add audio callback:

mpv-player/mpv#5566

Could anyone fix code style issues in this PR?

Note my previous comment here which states:

The issue with this however, is that the audio begins to stutter when using this audio callback.

So some fixing and testing is also required to fix this audio stuttering, not just aesthetic changes.