Hi John, On 2/17/20 1:16 PM, John Cox wrote: > Hi > > I have built a H265 V4L2 request decoder and I based it on the staged > sunxi cedrus decoder. As it stands it appears to me that in the request > environment one request comes in which is processed and then is acked > with v4l2_m2m_buf_done_and_job_finish which returns the output & capture > (if not held) buffers and then the next request can start. Our decode > process has two passes and so is most efficient if two frames are being > processed at the same time. Is it possible in the stateless request > world to separate the return of the output & capture buffers and/or to > allow multiple requests to be active at the same time? If so is there > any example code I can look at? If I understand it correctly, you want to start two buffers in flight at the same time: one doing phase 1, and the other in phase 2. And when both phases finish processing you return the buffer in phase 2, move the buffer in phase 1 to phase 2, and dequeue a new buffer to start processing in phase 1. Right? This means that there are two jobs running, and I don't think the framework likes that. On the other hand, I think it should be possible to add support for this in v4l2-mem2mem.c, although I am not entirely sure what the right approach would be. One idea would be to model a pipeline as part of a job: so you can have multiple jobs running, but each would run at a different phase of the pipeline. Erm, for the record, I have no plans to implement this, but patches are welcome! :-) Regards, Hans
