On Fri, Dec 10, 2010 at 12:40 PM, Kukjin Kim <kgene.kim@xxxxxxxxxxx> wrote: > 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... Each preference is different and you and me are different unfortunately. > > And I have a wondering about your sign. > Did you really check this patch before Kamil's submitting? > Unfortunately, I don't think so... I don't care minor issues I'm more focus on the logic. What's the matter mfc or mfc5 and so on? some time later these names are changed if new mfc are introduced. Currently we're use the mfc version 5. Do you have any rules on samsung soc variable, module naming? I think it depends on each case by case. Thank you, Kyungmin Park -- 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
