From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,UNPARSEABLE_RELAY,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 232E2C43381 for ; Tue, 5 Mar 2019 19:54:37 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E80CF205F4 for ; Tue, 5 Mar 2019 19:54:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Ndk+UkHV" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E80CF205F4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=collabora.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Date:To:From:Subject:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=nTD33Z3kQqaunjBCpJ5ebH+GI7nYyTlws//zBK+2i78=; b=Ndk+UkHVT18YRa i/nertJtLaMIuCESIvtnlIiL82/0Kx68MSiKqrtSdsqnyqFcAP0aSD/3KU/huunY7Id/LfiV7tyym 7NgFG+gVxOOw00ZjfkKMJzbtmqlkqR8MLMDPTl5ep9n9nhdlkFMdN7pcAyFGebVo8oKdJCW9tjSbp VwvdQuFuWtAiqtCNgrquHMUAN1w2Z81MRvnFNet8iMeKe87wCPELqab+z7z+595a2vEd0b+i8Q+X3 VscAFUpWoOobgkYA2cILXZruK8rs1xeqhzgUWSA83TWHAxuSziT8/HKfOYbRExmjlAibKns+zD7pL 9fJzo4cnjH+Gk6N8X3Jw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1h1G8w-0004VK-5t; Tue, 05 Mar 2019 19:54:26 +0000 Received: from bhuna.collabora.co.uk ([2a00:1098:0:82:1000:25:2eeb:e3e3]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1h1G8s-0004UX-GA for linux-arm-kernel@lists.infradead.org; Tue, 05 Mar 2019 19:54:24 +0000 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: ezequiel) with ESMTPSA id DB3F327DB33 Message-ID: <657a6931feb85b6117f16d75a3643d7ea87de79a.camel@collabora.com> Subject: Re: [PATCH v4 1/2] media: uapi: Add H264 low-level decoder API compound controls. From: Ezequiel Garcia To: Maxime Ripard , Tomasz Figa Date: Tue, 05 Mar 2019 16:54:06 -0300 In-Reply-To: <20190305111625.or44y4k7or25v44s@flea> References: <9817c9875638ed2484d61e6e128e2551cf3bda4c.1550672228.git-series.maxime.ripard@bootlin.com> <20190305111625.or44y4k7or25v44s@flea> Organization: Collabora User-Agent: Evolution 3.30.5-1 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190305_115422_993488_FD81BAB5 X-CRM114-Status: GOOD ( 26.26 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "list@263.net:IOMMU DRIVERS , Joerg Roedel , " , Thomas Petazzoni , Alexandre Courbot , Jonas Karlman , jenskuske@gmail.com, linux-sunxi@googlegroups.com, Linux Kernel Mailing List , Jernej Skrabec , Paul Kocialkowski , Chen-Yu Tsai , Hans Verkuil , Laurent Pinchart , Sakari Ailus , Guenter Roeck , Nicolas Dufresne , Pawel Osciak , Linux Media Mailing List Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, 2019-03-05 at 12:16 +0100, Maxime Ripard wrote: > On Fri, Feb 22, 2019 at 04:46:17PM +0900, Tomasz Figa wrote: > > Hi Maxime, > > > > On Wed, Feb 20, 2019 at 11:17 PM Maxime Ripard > > wrote: > > > From: Pawel Osciak > > > > > > Stateless video codecs will require both the H264 metadata and slices in > > > order to be able to decode frames. > > > > > > This introduces the definitions for a new pixel format for H264 slices that > > > have been parsed, as well as the structures used to pass the metadata from > > > the userspace to the kernel. > > > > > > Co-Developped-by: Maxime Ripard > > > Signed-off-by: Pawel Osciak > > > Signed-off-by: Guenter Roeck > > > Signed-off-by: Maxime Ripard > > > > Thanks for the patch. Some comments inline. > > > > [snip] > > > +``V4L2_CID_MPEG_VIDEO_H264_SLICE_PARAMS (struct)`` > > > + Specifies the slice parameters (as extracted from the bitstream) > > > + for the associated H264 slice data. This includes the necessary > > > + parameters for configuring a stateless hardware decoding pipeline > > > + for H264. The bitstream parameters are defined according to > > > + :ref:`h264`. Unless there's a specific comment, refer to the > > > + specification for the documentation of these fields, section 7.4.3 > > > + "Slice Header Semantics". > > > > Note that this is expected to be an array, with entries for all the > > slices included in the bitstream buffer. > > > > > + > > > + .. note:: > > > + > > > + This compound control is not yet part of the public kernel API and > > > + it is expected to change. > > > + > > > +.. c:type:: v4l2_ctrl_h264_slice_param > > > + > > > +.. cssclass:: longtable > > > + > > > +.. flat-table:: struct v4l2_ctrl_h264_slice_param > > > + :header-rows: 0 > > > + :stub-columns: 0 > > > + :widths: 1 1 2 > > > + > > > + * - __u32 > > > + - ``size`` > > > + - > > > + * - __u32 > > > + - ``header_bit_size`` > > > + - > > > + * - __u16 > > > + - ``first_mb_in_slice`` > > > + - > > > + * - __u8 > > > + - ``slice_type`` > > > + - > > > + * - __u8 > > > + - ``pic_parameter_set_id`` > > > + - > > > + * - __u8 > > > + - ``colour_plane_id`` > > > + - > > > + * - __u8 > > > + - ``redundant_pic_cnt`` > > > + - > > > + * - __u16 > > > + - ``frame_num`` > > > + - > > > + * - __u16 > > > + - ``idr_pic_id`` > > > + - > > > + * - __u16 > > > + - ``pic_order_cnt_lsb`` > > > + - > > > + * - __s32 > > > + - ``delta_pic_order_cnt_bottom`` > > > + - > > > + * - __s32 > > > + - ``delta_pic_order_cnt0`` > > > + - > > > + * - __s32 > > > + - ``delta_pic_order_cnt1`` > > > + - > > > + * - struct :c:type:`v4l2_h264_pred_weight_table` > > > + - ``pred_weight_table`` > > > + - > > > + * - __u32 > > > + - ``dec_ref_pic_marking_bit_size`` > > > + - > > > + * - __u32 > > > + - ``pic_order_cnt_bit_size`` > > > + - > > > + * - __u8 > > > + - ``cabac_init_idc`` > > > + - > > > + * - __s8 > > > + - ``slice_qp_delta`` > > > + - > > > + * - __s8 > > > + - ``slice_qs_delta`` > > > + - > > > + * - __u8 > > > + - ``disable_deblocking_filter_idc`` > > > + - > > > + * - __s8 > > > + - ``slice_alpha_c0_offset_div2`` > > > + - > > > + * - __s8 > > > + - ``slice_beta_offset_div2`` > > > + - > > > + * - __u8 > > > + - ``num_ref_idx_l0_active_minus1`` > > > + - > > > + * - __u8 > > > + - ``num_ref_idx_l1_active_minus1`` > > > + - > > > + * - __u32 > > > + - ``slice_group_change_cycle`` > > > + - > > > + * - __u8 > > > + - ``ref_pic_list0[32]`` > > > + - > > > + * - __u8 > > > + - ``ref_pic_list1[32]`` > > > + - > > > > Should we explicitly document that these are the lists after applying > > the per-slice modifications, as opposed to the original order from > > v4l2_ctrl_h264_decode_param? > > > > [snip] > > > + * .. _V4L2-PIX-FMT-H264-SLICE: > > > + > > > + - ``V4L2_PIX_FMT_H264_SLICE`` > > > + - 'S264' > > > + - H264 parsed slice data, as extracted from the H264 bitstream. > > > + This format is adapted for stateless video decoders that > > > + implement an H264 pipeline (using the :ref:`codec` and > > > + :ref:`media-request-api`). Metadata associated with the frame > > > + to decode are required to be passed through the > > > + ``V4L2_CID_MPEG_VIDEO_H264_SPS``, > > > + ``V4L2_CID_MPEG_VIDEO_H264_PPS``, > > > + ``V4L2_CID_MPEG_VIDEO_H264_SLICE_PARAMS`` and > > > + ``V4L2_CID_MPEG_VIDEO_H264_DECODE_PARAMS`` controls and > > > + scaling matrices can optionally be specified through the > > > + ``V4L2_CID_MPEG_VIDEO_H264_SCALING_MATRIX`` control. See the > > > + :ref:`associated Codec Control IDs `. > > > + Exactly one output and one capture buffer must be provided for > > > + use with this pixel format. The output buffer must contain the > > > + appropriate number of macroblocks to decode a full > > > + corresponding frame to the matching capture buffer. > > > > What does it mean that a control can be optionally specified? A > > control always has a value, so how do we decide that it was specified > > or not? Should we have another control (or flag) that selects whether > > to use the control? How is it better than just having the control > > initialized with the default scaling matrix and always using it? > > Ok, I'll change it. > > > > diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h > > > index 9a920f071ff9..6443ae53597f 100644 > > > --- a/include/uapi/linux/videodev2.h > > > +++ b/include/uapi/linux/videodev2.h > > > @@ -653,6 +653,7 @@ struct v4l2_pix_format { > > > #define V4L2_PIX_FMT_H264 v4l2_fourcc('H', '2', '6', '4') /* H264 with start codes */ > > > #define V4L2_PIX_FMT_H264_NO_SC v4l2_fourcc('A', 'V', 'C', '1') /* H264 without start codes */ > > > #define V4L2_PIX_FMT_H264_MVC v4l2_fourcc('M', '2', '6', '4') /* H264 MVC */ > > > +#define V4L2_PIX_FMT_H264_SLICE v4l2_fourcc('S', '2', '6', '4') /* H264 parsed slices */ > > > > Are we okay with adding here already, without going through staging first? > > This is what we did for MPEG-2 already (the format is public but the > controls are not), so I'm not sure this is causing any issue. > As pointed out by Nicolas on IRC, the V4L2_PIX_FMT_H264_SLICE_RAW and V4L2_PIX_FMT_H264_SLICE_ANNEX_B should describe pretty well the pixel format. I believe it's acceptable for them to go public. Thanks! Ezequiel _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel