Hi >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? Yes - that is exactly correct. >This means that there are two jobs running, and I don't think the >framework likes that. Looking at the code I got that impression quite strongly. >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. As I'm new to this area I have even less idea :-) >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. Comments? Does this seem like the way to go? If so I could have a first hack at it (though beware my unfamiliarity with this code - I'm still getting used to the usage of "output" & "capture"). >Erm, for the record, I have no plans to implement this, but patches are >welcome! :-) Bother :-) >Regards, > > Hans Regards John Cox
