Kyungmin Park wrote: > > On Fri, Dec 10, 2010 at 11:32 AM, Kukjin Kim <kgene.kim@xxxxxxxxxxx> wrote: > > 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... > > No need to cc all, only machine specific only. > and I hope minimal modification at machine specific and move to media > if possible. > Should be reviewed proper maintainer even though it is small changes. Really, I don't want to argue to you about my maintaining ship... And I have a wondering about your sign. Did you really check this patch before Kamil's submitting? Unfortunately, I don't think so... 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
