On Wed, Feb 13, 2019 at 6:22 AM Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx> wrote: > > Hey Tomasz, > > On Tue, 2019-02-12 at 21:50 +0900, Tomasz Figa wrote: > > Hi Maxime, > > > > On Mon, Feb 11, 2019 at 11:39 PM Maxime Ripard > > <maxime.ripard@xxxxxxxxxxx> wrote: > > > Hi, > > > > > > Here is a new version of the H264 decoding support in the cedrus > > > driver. > > > > Thanks for working on this. Please see my comments below. > > > > > As you might already know, the cedrus driver relies on the Request > > > API, and is a reverse engineered driver for the video decoding engine > > > found on the Allwinner SoCs. > > > > > > This work has been possible thanks to the work done by the people > > > behind libvdpau-sunxi found here: > > > https://github.com/linux-sunxi/libvdpau-sunxi/ > > > > > > I've tested the various ABI using this gdb script: > > > http://code.bulix.org/jl4se4-505620?raw > > > > > > And this test script: > > > http://code.bulix.org/8zle4s-505623?raw > > > > > > The application compiled is quite trivial: > > > http://code.bulix.org/e34zp8-505624?raw > > > > > > The output is: > > > arm: builds/arm-test-v4l2-h264-structures > > > SHA1: 88cbf7485ba81831fc3b93772b215599b3b38318 > > > x86: builds/x86-test-v4l2-h264-structures > > > SHA1: 88cbf7485ba81831fc3b93772b215599b3b38318 > > > x64: builds/x64-test-v4l2-h264-structures > > > SHA1: 88cbf7485ba81831fc3b93772b215599b3b38318 > > > arm64: builds/arm64-test-v4l2-h264-structures > > > SHA1: 88cbf7485ba81831fc3b93772b215599b3b38318 > > > > > > Let me know if there's any flaw using that test setup, or if you have > > > any comments on the patches. > > > > > > Maxime > > > > > > Changes from v2: > > > - Simplified _cedrus_write_ref_list as suggested by Jernej > > > - Set whether the frame is used as reference using nal_ref_idc > > > - Respect chroma_format_idc > > > - Fixes for the scaling list and prediction tables > > > - Wrote the documentation for the flags > > > - Added a bunch of defines to the driver bit fields > > > - Reworded the controls and data format descriptions as suggested > > > by Hans > > > - Reworked the controls' structure field size to avoid padding > > > - Removed the long term reference flag > > > > This and... > > > > Maxime has dropped this because of Ayaka's mail about long term references > not making much sense in stateless decoders. I haven't seen any argument confirming that thesis, though. I should have kicked in earlier, sorry. > > I noticed that RK3399 TRM has a field to specify long term refs and > so was wondering about this item as well. > > > > - Reintroduced the neighbor info buffer > > > - Removed the ref_pic_list_p0/b0/b1 arrays that are redundant with the > > > one in the DPB > > > > these are used in our Rockchip VDEC driver. > > > > Could you elaborate on the reasons why they got removed? > > > > If I understood correctly, there are two reference picture lists. > P-frames will populate ref_pic_list0 and B-frames will populate both. > > According to this, v4l2_ctrl_h264_slice_param.ref_pic_list0 and .ref_pic_list1 > should be enough and ref_pic_list_p0/b0/b1 are not needed. > > What do you think? The lists in v4l2_ctrl_h264_slice_param are expected to be past the per-slice modification stage (which is quite complicated and better done in userspace), while the ones in v4l2_ctrl_h264_decode_param just in the original order. Rockchip VPU expects them in the original order and does the modification in the hardware. Best regards, Tomasz
