On Tue, Jan 14, 2025 at 10:16 AM Nicolas Dufresne <nicolas.dufresne@xxxxxxxxxxxxx> wrote: > > Hi everyone, > > despite Andrzej having left the community, we are not giving up on the encoder > work. In 2025, we aim at working more seriously on the V4L2 spec, as just > writing driver won't cut it. Each class of codecs needs a general workflow spec > similar to what we have already for stateful encoder/decoder and stateless > decoder. > > - https://www.kernel.org/doc/html/latest/userspace-api/media/v4l/dev-decoder.html > - https://www.kernel.org/doc/html/latest/userspace-api/media/v4l/dev-encoder.html > - https://www.kernel.org/doc/html/latest/userspace-api/media/v4l/dev-stateless-decoder.html > > It is on top of this, that for each codec we have to add controls (mostly > compound) specifics and details that suites stateless accelerators. > > From a community stand point, the most important focus is to write and agree on > spec and controls. Once we have that, vendors will be able to slowly move away > from their custom solution, and compete on actual hardware rather then > integration. > > It is also time to start looking toward the future, since Hantro H1 is very > limited and ancient encoder. On same brand, if someone could work on VC8000E > shipped on IMX8M Plus, or Rockchip codecs, that will certainly help progress. We > can also get inspiration from many other stateless encoding APIs now, notably > VA, DXVA and Vulkan Video. I have an 8MP and I looked at the VC800E a little, and I attempted to port what was done before to the 8MM. If that's a sufficient place to start, I can give it a try, but if the userpace isn't finalized, I am not sure how to test it. > > Of course, folks likes to know when this will happen, stateless decoders took 5 > years from start to the first codec being merged, hopefully we don't beat that > record. I personally aim for producing work during the summer, and mostly focus > on the spec. Its obvious for me that testing on H1 with a GStreamer > implementation is the most productive, though I have strong interest in having > an ecosystem of drivers. A second userspace implementation, perhaps ffmpeg ?, > could also be useful. > > If you'd like to take a bite, this is a good thread to discuss forward. Until > the summer, I planned to reach to Paul, who made this great presentation [1] at > FOSDEM last year and start moving the RFC into using these ideas. One of the > biggest discussion is rate control, it is clear to me that modern HW integrated > RC offloading, though some HW specific knobs or even firmware offloading, and > this is what Paul has been putting some thought into. I'll take a look at the presentation. I will admit that I am not an expert on the video formats or how the encoding works, but I'm willing to try. > > If decoders have progressed so much in quality in the last few years, it is > mostly before we have better ways to test them. It is also needed to start > thinking how do we want to test our encoders. The stateful scene is not all > green, with a very organic groth and difficult to unify set of encoders. And we > have no metric of how good or bad they are either. adam > > regards, > Nicolas > > Le lundi 13 janvier 2025 à 18:08 -0300, Daniel Almeida a écrit : > > +cc Nicolas > > > > > > Hey Adam, > > > > > > > > > > Daniel, > > > > > > Do you know if anyone will be picking up the H1 encoder? > > > > > > adam > > > > > > > > — Daniel > > > > > > > > > > > I think my colleague Nicolas is the best person to answer this. > > > > — Daniel >
