Kamil Debski wrote: > > Hello, > > Last week v3 of this driver has been posted. Since then the driver was > changed > to use the newest videobuf2 version - v6. Two very long functions have been > split to make the code more readible. Minor changes include tidying the > comments and replacing remaining magic numbers with defines. > > I would be grateful for your comments. Original cover letter ant detailed > change > log has been attached below. > > Best regards, > Kamil Debski > > * Changelog: > > ================== > Changes since v3 > ================== > > 1) Update to the v6 videobuf2 API (here thanks go to Marek Szyprowski) > - s5p_mfc_buf_negotiate and s5p_mfc_buf_setup_plane functions > have been merged > - queue initialization has been adapted to the new API > - use of the allocator memops has been changed, now there are single > memops for all the allocator contexts > > 2) Split of the s5p_mfc_try_run and s5p_mfc_handle_frame_int functions > - parts of the s5p_mfc_try_run function have been moved to separate > functions (s5p_mfc_get_new_ctx, s5p_mfc_run_dec_last_frames, > s5p_mfc_run_dec_frame, s5p_mfc_run_get_inst_no, s5p_mfc_run_return_inst > s5p_mfc_run_init_dec,s5p_mfc_run_init_dec_buffers) > - s5p_mfc_handle_frame_int has been split to the following functions: > s5p_mfc_handle_frame_all_extracted, s5p_mfc_handle_frame_new > and s5p_mfc_handle_frame to handle different cases > > 3) Remove remaining magic numbers and tidy up comments > > ================== > Changes since v2 > ================== > > 1) Update to newest videobuf2 API > This is the major change from v2. The videobuf2 API will hopefully have no > more > major API changes. Buffer initialization has been moved from buf_prepare > callback to buf_init to simplify the process. Locking mechanism has been > modified to the requirements of new videobuf2 version. > 2) Code cleanup > Removed more magic contants and replaced them with appropriate defines. > Changed > code to use unlocked_ioctl instead of ioctl in v4l2 file ops. > 3) Allocators > All internal buffer allocations are done using the selected vb2 allocator, > instead of using CMA functions directly. > > ================== > Changes since v1 > ================== > > 1) Cleanup accoridng to Peter Oh suggestions on the mailing list (Thanks). > > * Original cover letter: > > ============== > Introduction > ============== > > The purpose of this RFC is to discuss the driver for a hw video codec > embedded in the new Samusng's SoCs. Multi Format Codec 5.0 is able to > handle video decoding of in a range of formats. > > So far no hardware codec was supported in V4L2 and this would be the > first one. I guess there are more similar device that would benefit from > a V4L2 unified interface. I suggest a separate control class for codec > devices - V4L2_CTRL_CLASS_CODEC. > > Internally the driver uses videobuf2 framework and CMA memory allocator. > I am aware that those have not yet been merged, but I wanted to start > discussion about the driver earlier so it could be merged sooner. The > driver posted here is the initial version, so I suppose it will require > more work. > > ================== > Device interface > ================== > > The driver principle is based on the idea of memory-to-memory devices: > it provides a single video node and each opened file handle gets its own > private context with separate buffer queues. Each context consist of 2 > buffer queues: OUTPUT (for source buffers, i.e. encoded video frames) > and CAPTURE (for destination buffers, i.e. decoded raw video frames). > The process of decoding video data from stream is a bit more complicated > than typical memory-to-memory processing, that's why the m2m framework > is not directly used (it is too limited for this case). The main reason > for this is the fact that the CAPTURE buffers can be dequeued in a > different order than they queued. The hw block decides which buffer has > been completely processed. This is due to the structure of most > compressed video streams - use of B frames causes that decoding and > display order may be different. > > ============================== > Decoding initialization path > ============================== > > First the OUTPUT queue is initialized. With S_FMT the application > chooses which video format to decode and what size should be the input > buffer. Fourcc values have been defined for different codecs e.g. > V4L2_PIX_FMT_H264 for h264. Then the OUTPUT buffers are requested and > mmaped. The stream header frame is loaded into the first buffer, queued > and streaming is enabled. At this point the hardware is able to start > processing the stream header and afterwards it will have information > about the video dimensions and the size of the buffers with raw video > data. > > The next step is setting up the CAPTURE queue and buffers. The width, > height, buffer size and minimum number of buffers can be read with G_FMT > call. The application can request more output buffer if necessary. After > requesting and mmaping buffers the device is ready to decode video > stream. > > The stream frames (ES frames) are written to the OUTPUT buffers, and > decoded video frames can be read from the CAPTURE buffers. When no more > source frames are present a single buffer with bytesused set to 0 should > be queued. This will inform the driver that processing should be > finished and it can dequeue all video frames that are still left. The > number of such frames is dependent on the stream and its internal > structure (how many frames had to be kept as reference frames for > decoding, etc). > > =============== > Usage summary > =============== > > This is a step by step summary of the video decoding (from user > application point of view, with 2 treads and blocking api): > > 01. S_FMT(OUTPUT, V4L2_PIX_FMT_H264, ...) > 02. REQ_BUFS(OUTPUT, n) > 03. for i=1..n MMAP(OUTPUT, i) > 04. put stream header to buffer #1 > 05. QBUF(OUTPUT, #1) > 06. STREAM_ON(OUTPUT) > 07. G_FMT(CAPTURE) > 08. REQ_BUFS(CAPTURE, m) > 09. for j=1..m MMAP(CAPTURE, j) > 10. for j=1..m QBUF(CAPTURE, #j) > 11. STREAM_ON(CAPTURE) > > display thread: > 12. DQBUF(CAPTURE) -> got decoded video data in buffer #j > 13. display buffer #j > 14. QBUF(CAPTURE, #j) > 15. goto 12 > > parser thread: > 16. put next ES frame to buffer #i > 17. QBUF(OUTPUT, #i) > 18. DQBUF(OUTPUT) -> get next empty buffer #i 19. goto 16 > > ... > > Similar usage sequence can be achieved with single threaded application > and non-blocking api with poll() call. > > Branch with MFC, CMA and videobuf2 will be soon available at > http://git.infradead.org/users/kmpark/linux-2.6- > samsung/shortlog/refs/heads/vb2-mfc-fimc > This tree is based on 2.6.37 rc4. > > Please have a look at the code and the idea of how to introduce codec > devices to V4L2. Comments will be very much appreciated. > > Patch summary: > > Kamil Debski (4): > Changes in include/linux/videodev2.h for MFC > MFC: Add MFC 5.1 driver to plat-s5p, mach-s5pv210 and mach-s5pv210 > MFC: Added MFC 5.1 V4L2 driver > s5pv210: Enable MFC on Goni > > arch/arm/mach-s5pv210/Kconfig | 1 + > arch/arm/mach-s5pv210/clock.c | 6 + > arch/arm/mach-s5pv210/include/mach/map.h | 4 + > arch/arm/mach-s5pv210/mach-goni.c | 1 + > arch/arm/plat-s5p/Kconfig | 5 + > arch/arm/plat-s5p/Makefile | 1 + > arch/arm/plat-s5p/dev-mfc5.c | 37 + > arch/arm/plat-samsung/include/plat/devs.h | 2 + > drivers/media/video/Kconfig | 8 + > drivers/media/video/Makefile | 1 + > drivers/media/video/s5p-mfc/Makefile | 3 + > drivers/media/video/s5p-mfc/regs-mfc5.h | 335 ++++ > drivers/media/video/s5p-mfc/s5p_mfc.c | 2031 > +++++++++++++++++++++++ > drivers/media/video/s5p-mfc/s5p_mfc_common.h | 222 +++ > drivers/media/video/s5p-mfc/s5p_mfc_ctrls.h | 173 ++ > drivers/media/video/s5p-mfc/s5p_mfc_debug.h | 47 + > drivers/media/video/s5p-mfc/s5p_mfc_intr.c | 92 + > drivers/media/video/s5p-mfc/s5p_mfc_intr.h | 26 + > drivers/media/video/s5p-mfc/s5p_mfc_memory.h | 43 + > drivers/media/video/s5p-mfc/s5p_mfc_opr.c | 870 ++++++++++ > drivers/media/video/s5p-mfc/s5p_mfc_opr.h | 131 ++ > include/linux/videodev2.h | 48 + > 25 files changed, 4136 insertions(+), 1 deletions(-) > create mode 100644 arch/arm/plat-s5p/dev-mfc5.c > create mode 100644 drivers/media/video/s5p-mfc/Makefile > create mode 100644 drivers/media/video/s5p-mfc/regs-mfc5.h > create mode 100644 drivers/media/video/s5p-mfc/s5p_mfc.c > create mode 100644 drivers/media/video/s5p-mfc/s5p_mfc_common.h > create mode 100644 drivers/media/video/s5p-mfc/s5p_mfc_ctrls.h > create mode 100644 drivers/media/video/s5p-mfc/s5p_mfc_debug.h > create mode 100644 drivers/media/video/s5p-mfc/s5p_mfc_intr.c > create mode 100644 drivers/media/video/s5p-mfc/s5p_mfc_intr.h > create mode 100644 drivers/media/video/s5p-mfc/s5p_mfc_memory.h > create mode 100644 drivers/media/video/s5p-mfc/s5p_mfc_opr.c > create mode 100644 drivers/media/video/s5p-mfc/s5p_mfc_opr.h > Hi Kamil, I think, should be added my e-mail in Cc... Thanks. Best regards, Kgene. -- Kukjin Kim <kgene.kim@xxxxxxxxxxx>, Senior Engineer, SW Solution Development Team, Samsung Electronics Co., Ltd. -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
