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=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 4FE5DC32753 for ; Wed, 14 Aug 2019 14:12:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2FEE9206C1 for ; Wed, 14 Aug 2019 14:12:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727111AbfHNOM2 (ORCPT ); Wed, 14 Aug 2019 10:12:28 -0400 Received: from bhuna.collabora.co.uk ([46.235.227.227]:55000 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725828AbfHNOM2 (ORCPT ); Wed, 14 Aug 2019 10:12:28 -0400 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: ezequiel) with ESMTPSA id 78E88286289 Message-ID: Subject: Re: [PATCH v5 04/11] media: uapi: h264: Add the concept of start code From: Ezequiel Garcia To: Paul Kocialkowski , Hans Verkuil Cc: linux-media@vger.kernel.org, kernel@collabora.com, Nicolas Dufresne , Tomasz Figa , linux-rockchip@lists.infradead.org, Heiko Stuebner , Jonas Karlman , Philipp Zabel , Boris Brezillon , Alexandre Courbot , fbuergisser@chromium.org, linux-kernel@vger.kernel.org Date: Wed, 14 Aug 2019 11:12:16 -0300 In-Reply-To: <20190814114928.GB4687@aptenodytes> References: <20190812193522.10911-1-ezequiel@collabora.com> <20190812193522.10911-5-ezequiel@collabora.com> <20190814114928.GB4687@aptenodytes> 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-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org On Wed, 2019-08-14 at 13:49 +0200, Paul Kocialkowski wrote: > Hi, > > On Wed 14 Aug 19, 10:11, Hans Verkuil wrote: > > On 8/12/19 9:35 PM, Ezequiel Garcia wrote: > > > Stateless decoders have different expectations about the > > > start code that is prepended on H264 slices. Add a > > > menu control to express the supported start code types > > > (including no start code). > > > > > > Drivers are allowed to support only one start code type, > > > but they can support both too. > > > > > > Note that this is independent of the H264 decoding mode, > > > which specifies the granularity of the decoding operations. > > > Either in frame-based or slice-based mode, this new control > > > will allow to define the start code expected on H264 slices. > > > > > > Signed-off-by: Ezequiel Garcia > > > Tested-by: Philipp Zabel > > > --- > > > Changes in v5: > > > * Improve specification as suggested by Hans. > > > Changes in v4: > > > * New patch. > > > --- > > > .../media/uapi/v4l/ext-ctrls-codec.rst | 33 +++++++++++++++++++ > > > .../media/uapi/v4l/pixfmt-compressed.rst | 3 +- > > > drivers/media/v4l2-core/v4l2-ctrls.c | 9 +++++ > > > include/media/h264-ctrls.h | 6 ++++ > > > 4 files changed, 50 insertions(+), 1 deletion(-) > > > > > > > > > > > > diff --git a/include/media/h264-ctrls.h b/include/media/h264-ctrls.h > > > index e6c510877f67..31555c99f64a 100644 > > > --- a/include/media/h264-ctrls.h > > > +++ b/include/media/h264-ctrls.h > > > @@ -27,6 +27,7 @@ > > > #define V4L2_CID_MPEG_VIDEO_H264_SLICE_PARAMS (V4L2_CID_MPEG_BASE+1003) > > > #define V4L2_CID_MPEG_VIDEO_H264_DECODE_PARAMS (V4L2_CID_MPEG_BASE+1004) > > > #define V4L2_CID_MPEG_VIDEO_H264_DECODING_MODE (V4L2_CID_MPEG_BASE+1005) > > > +#define V4L2_CID_MPEG_VIDEO_H264_STARTCODE (V4L2_CID_MPEG_BASE+1006) > > > > I almost forgot: can you change this to _START_CODE? Since it is two words? > > Agreed, I like it better this way too. > The reason to have STARTCODE instead of START_CODE was to have some consistency with other controls (namely, V4L2_CID_MPEG_VIDEO_HEVC_WITHOUT_STARTCODE). Consistency is really important in a API, but at the same time, I agree START_CODE looks better. > > Thanks! > > > > Hans > > > > > > > > /* enum v4l2_ctrl_type type values */ > > > #define V4L2_CTRL_TYPE_H264_SPS 0x0110 > > > @@ -41,6 +42,11 @@ enum v4l2_mpeg_video_h264_decoding_mode { > > > V4L2_MPEG_VIDEO_H264_FRAME_BASED_DECODING, > > > }; > > > > > > +enum v4l2_mpeg_video_h264_start_code { > > > + V4L2_MPEG_VIDEO_H264_NO_STARTCODE, > > > + V4L2_MPEG_VIDEO_H264_ANNEX_B_STARTCODE, > > Could we apply the same START_CODE renaming here too? > > I was also thinking that it would be slightly more readable put like this, > with START_CODE as a prefix since it's common to both options and the name of > the enum: > > - V4L2_MPEG_VIDEO_H264_START_CODE_NONE > - V4L2_MPEG_VIDEO_H264_START_CODE_ANNEX_B > Yes, that looks much better. Thanks, Ezequiel