As was discussed here (among other places): https://lkml.org/lkml/2018/10/19/440 using capture queue buffer indices to refer to reference frames is not a good idea. A better idea is to use 'cookies' (a better name is welcome!) where the application can assign a u64 cookie to an output buffer, which is then copied to the capture buffer(s) derived from the output buffer. A u64 is chosen since this allows userspace to also use pointers to internal structures as 'cookie'. The first two patches add core cookie support, the next two patches add cookie support to vim2m and vicodec, and the final patch (compile tested only!) adds support to the cedrus driver. I also removed the 'pad' fields from the mpeg2 control structs (it should never been added in the first place) and aligned the structs to a u32 boundary (u64 for the cookie values). The cedrus code now also copies the timestamps (didn't happen before) but the sequence counter is still not set, that's something that should still be added. Note: if no buffer is found for a certain cookie, then the dma address is just set to 0. That happened before as well with invalid buffer indices. This should be checked in the driver! Also missing in this series are documentation updates, which is why it is marked RFC. I would very much appreciate it if someone can test the cedrus driver with these changes. If it works, then I can prepare a real patch series for 4.20. It would be really good if the API is as stable as we can make it before 4.20 is released. Regards, Hans Hans Verkuil (5): videodev2.h: add cookie support vb2: add cookie support vim2m: add cookie support vicodec: add cookie support cedrus: add cookie support .../media/common/videobuf2/videobuf2-v4l2.c | 41 ++++++++++++++++--- drivers/media/platform/vicodec/vicodec-core.c | 3 ++ drivers/media/platform/vim2m.c | 3 ++ drivers/media/v4l2-core/v4l2-ctrls.c | 9 ---- drivers/staging/media/sunxi/cedrus/cedrus.h | 8 ++-- .../staging/media/sunxi/cedrus/cedrus_dec.c | 10 +++++ .../staging/media/sunxi/cedrus/cedrus_mpeg2.c | 23 +++++------ include/media/videobuf2-v4l2.h | 18 ++++++++ include/uapi/linux/v4l2-controls.h | 14 +++---- include/uapi/linux/videodev2.h | 36 +++++++++++++++- 10 files changed, 126 insertions(+), 39 deletions(-) -- 2.19.1
