Hi all, The Hantro G1 VPU post-processor block can be pipelined with the decoder hardware, allowing to perform operations such as color conversion, scaling, rotation, cropping, among others. When the post-processor is enabled, the decoder hardware needs its own set of NV12 buffers (the native decoder format), and the post-processor is the owner of the CAPTURE buffers, allocated for the post-processed format. This way, applications obtain post-processed (scaled, converted, etc) buffers transparently. This feature is implemented by exposing the post-processed pixel formats on ENUM_FMT, ordered as "preferred pixelformat first": v4l2-ctl -d 1 --list-formats ioctl: VIDIOC_ENUM_FMT Type: Video Capture Multiplanar [0]: 'NV12' (Y/CbCr 4:2:0) [1]: 'YUYV' (YUYV 4:2:2) The order of preference in ENUM_FMT can be used as a hint by applications. This series updates the uAPI specification accordingly. When the application sets a pixel format other than NV12, the post-processor is transparently enabled. Patch 1 is a cleanups needed to easier integrate the post-processor. Patch 2 introduces the post-processing support. Patch 3 updates the uAPI specification. This is tested on RK3288 platforms with MPEG-2, VP8 and H264 streams, decoding to YUY2 surfaces. For now, this series is only adding support for NV12-to-YUY2 conversion. Applies to media/master. Future plans ------------ It seems to me that we should start moving this driver to use regmap-based access to registers. However, such move is out of scope and not entirely related to this post-processor enablement. We'll work on that as follow-up patches. Changelog --------- Changes v3: * After discussing with Hans and Tomasz during the media summit in ELCE, we decided to go back on the MC changes. The MC topology is now untouched. This means the series is now similar to v1, except we explicitly use the ENUM_FMT to hint about the post-processed formats. Changes v2: * The decoder->post-processor topology is now exposed explicitly and applications need to configure the pipeline. By default, the decoder is enabled and the post-processor is disabled. * RGB post-processing output has been dropped. We might add this in the future, but for now, it seems it would make the code more complex without a use-case in mind. RGB is much more memory-consuming so less attractive than YUV, and modern GPUs and display controllers support YUV. * The post-processor implementation still supports RK3288 only. However, a generic register infrastructure is introduced to make addition of other variants such as RK3399 really easy. Ezequiel Garcia (3): media: hantro: Cleanup format negotiation helpers media: hantro: Support color conversion via post-processing media: vidioc-enum-fmt.rst: clarify format preference .../media/uapi/v4l/vidioc-enum-fmt.rst | 4 +- drivers/staging/media/hantro/Makefile | 1 + drivers/staging/media/hantro/hantro.h | 64 +++++++- drivers/staging/media/hantro/hantro_drv.c | 8 +- .../staging/media/hantro/hantro_g1_h264_dec.c | 2 +- .../media/hantro/hantro_g1_mpeg2_dec.c | 2 +- drivers/staging/media/hantro/hantro_g1_regs.h | 53 +++++++ .../staging/media/hantro/hantro_g1_vp8_dec.c | 2 +- drivers/staging/media/hantro/hantro_h264.c | 6 +- drivers/staging/media/hantro/hantro_hw.h | 13 ++ .../staging/media/hantro/hantro_postproc.c | 141 ++++++++++++++++++ drivers/staging/media/hantro/hantro_v4l2.c | 105 ++++++++----- drivers/staging/media/hantro/rk3288_vpu_hw.c | 10 ++ 13 files changed, 366 insertions(+), 45 deletions(-) create mode 100644 drivers/staging/media/hantro/hantro_postproc.c -- 2.22.0
