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=-6.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,URIBL_BLOCKED autolearn=ham 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 BB520C3A59E for ; Fri, 16 Aug 2019 12:29:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9AD5C20644 for ; Fri, 16 Aug 2019 12:29:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727246AbfHPM30 (ORCPT ); Fri, 16 Aug 2019 08:29:26 -0400 Received: from bhuna.collabora.co.uk ([46.235.227.227]:47932 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727087AbfHPM30 (ORCPT ); Fri, 16 Aug 2019 08:29:26 -0400 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: ezequiel) with ESMTPSA id 3C8FC26127B Message-ID: <3c7d72f3ae3a4235cd818a051ee0265ac123bdc1.camel@collabora.com> Subject: Re: [PATCH v6 03/11] media: uapi: h264: Add the concept of decoding mode From: Ezequiel Garcia To: Hans Verkuil , linux-media@vger.kernel.org Cc: kernel@collabora.com, Nicolas Dufresne , Tomasz Figa , linux-rockchip@lists.infradead.org, Heiko Stuebner , Jonas Karlman , Philipp Zabel , Boris Brezillon , Paul Kocialkowski , Alexandre Courbot , fbuergisser@chromium.org, linux-kernel@vger.kernel.org Date: Fri, 16 Aug 2019 09:29:13 -0300 In-Reply-To: <38911c55-3ca7-4fd8-d10e-34f48a5a2851@xs4all.nl> References: <20190814195931.6587-1-ezequiel@collabora.com> <20190814195931.6587-4-ezequiel@collabora.com> <38911c55-3ca7-4fd8-d10e-34f48a5a2851@xs4all.nl> Organization: Collabora Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.30.5-1.1 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2019-08-16 at 09:34 +0200, Hans Verkuil wrote: > On 8/14/19 9:59 PM, Ezequiel Garcia wrote: > > From: Boris Brezillon > > > > Some stateless decoders don't support per-slice decoding granularity > > (or at least not in a way that would make them efficient or easy to use). > > > > Expose a menu to control the supported decoding modes. Drivers are > > allowed to support only one decoding but they can support both too. > > The commit message doesn't say anything about the start_byte_offset > addition and the num_slices documentation improvement. It probably > should. > Yes, of course. > See more comments below: > > > Signed-off-by: Boris Brezillon > > Reviewed-by: Paul Kocialkowski > > Tested-by: Philipp Zabel > > --- > > Changes in v6: > > * Fix spec, specifiying the decode-mode pixelformat modifier > > needs to be set once, as suggested by Hans. > > * Rename, as suggested by Paul. > > Changes in v5: > > * Improve specification as suggested by Hans. > > Changes in v4: > > * Typos/rewording fixes > > Changes in v3: > > * s/per-{slice,frame} decoding/{slice,frame}-based decoding/ > > * Add Paul's R-b > > Changes in v2: > > * Allow decoding multiple slices in per-slice decoding mode > > * Minor doc improvement/fixes > > --- > > .../media/uapi/v4l/ext-ctrls-codec.rst | 47 ++++++++++++++++++- > > .../media/uapi/v4l/pixfmt-compressed.rst | 6 ++- > > drivers/media/v4l2-core/v4l2-ctrls.c | 9 ++++ > > include/media/h264-ctrls.h | 10 ++++ > > 4 files changed, 69 insertions(+), 3 deletions(-) > > > > diff --git a/Documentation/media/uapi/v4l/ext-ctrls-codec.rst b/Documentation/media/uapi/v4l/ext-ctrls-codec.rst > > index c5f39dd50043..623b34f61b32 100644 > > --- a/Documentation/media/uapi/v4l/ext-ctrls-codec.rst > > +++ b/Documentation/media/uapi/v4l/ext-ctrls-codec.rst > > @@ -1747,6 +1747,11 @@ enum v4l2_mpeg_video_h264_hierarchical_coding_type - > > * - __u32 > > - ``size`` > > - > > + * - __u32 > > + - ``start_byte_offset`` > > + Offset (in bytes) from the beginning of the OUTPUT buffer to the start > > + of the slice. If the slice starts with a start code, then this is the > > + offset to such start code. > > This should mention that it should be set to 0 for SLICE_BASED decoding mode. > Right. > > * - __u32 > > - ``header_bit_size`` > > - > > @@ -1930,7 +1935,10 @@ enum v4l2_mpeg_video_h264_hierarchical_coding_type - > > - > > * - __u16 > > - ``num_slices`` > > - - Number of slices needed to decode the current frame > > + - Number of slices needed to decode the current frame/field. When > > + operating in slice-based decoding mode (see > > + :c:type:`v4l2_mpeg_video_h264_decode_mode`), this field > > + should always be set to one. > > * - __u16 > > - ``nal_ref_idc`` > > - NAL reference ID value coming from the NAL Unit header > > @@ -2021,6 +2029,43 @@ enum v4l2_mpeg_video_h264_hierarchical_coding_type - > > - 0x00000004 > > - The DPB entry is a long term reference frame > > > > +``V4L2_CID_MPEG_VIDEO_H264_DECODE_MODE (enum)`` > > + Specifies the decoding mode to use. Currently exposes slice-based and > > + frame-based decoding but new modes might be added later on. > > + This control is used as a modifier for V4L2_PIX_FMT_H264_SLICE > > + pixel format. Applications that support V4L2_PIX_FMT_H264_SLICE > > + are required to set this control in order to specify the decoding mode > > + that is expected for the buffer. > > + Drivers may expose a single or multiple decoding modes, depending > > + on what they can support. > > + > > + .. note:: > > + > > + This menu control is not yet part of the public kernel API and > > + it is expected to change. > > + > > +.. c:type:: v4l2_mpeg_video_h264_decode_mode > > + > > +.. cssclass:: longtable > > + > > +.. flat-table:: > > + :header-rows: 0 > > + :stub-columns: 0 > > + :widths: 1 1 2 > > + > > + * - ``V4L2_MPEG_VIDEO_H264_DECODE_MODE_SLICE_BASED`` > > + - 0 > > + - Decoding is done at the slice granularity. > > + v4l2_ctrl_h264_decode_params->num_slices should be set to 1. > > And start_byte_offset should be set to 0. > OK. > > + The OUTPUT buffer must contain a single slice. > > + * - ``V4L2_MPEG_VIDEO_H264_DECODE_MODE_FRAME_BASED`` > > + - 1 > > + - Decoding is done at the frame granularity. > > + v4l2_ctrl_h264_decode_params->num_slices should be set to the number of > > + slices forming a frame. > > And start_byte_offset should be filled in accordingly for each slice. > OK. Thanks, Ezequiel