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=-0.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY autolearn=no 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 AC6C5C3A5A0 for ; Mon, 19 Aug 2019 14:39:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8BF5E206C1 for ; Mon, 19 Aug 2019 14:39:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726842AbfHSOjE (ORCPT ); Mon, 19 Aug 2019 10:39:04 -0400 Received: from bhuna.collabora.co.uk ([46.235.227.227]:53788 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726261AbfHSOjE (ORCPT ); Mon, 19 Aug 2019 10:39:04 -0400 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: ezequiel) with ESMTPSA id 92748283C05 Message-ID: Subject: Re: [PATCH v7 02/11] media: uapi: h264: Rename pixel format From: Ezequiel Garcia To: Paul Kocialkowski 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: Mon, 19 Aug 2019 11:38:51 -0300 In-Reply-To: <20190819124110.GB32182@aptenodytes> References: <20190816160132.7352-1-ezequiel@collabora.com> <20190816160132.7352-3-ezequiel@collabora.com> <20190819124110.GB32182@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 Mon, 2019-08-19 at 14:41 +0200, Paul Kocialkowski wrote: > Hi, > > On Fri 16 Aug 19, 13:01, Ezequiel Garcia wrote: > > The V4L2_PIX_FMT_H264_SLICE_RAW name was originally suggested > > because the pixel format would represent H264 slices without any > > start code. > > > > However, as we will now introduce a start code menu control, > > give the pixel format a more meaningful name, while it's > > still early enough to do so. > > I definitely agree that SLICE_RAW is not the suffix we are looking for, but I'm > not sure that _SLICE is self-describing given that we can operate either > per-frame or per-slice, and _SLICE sort of implies the latter. This is not entirely so, per-frame or per-slice mode refer to the granularity of the stateless API, the pixel format is still composed of H264 NALU slices. As per the documentation, the decode_mode and the start_code are modifiers of the pixel format. As long as this is properly speced, the V4L2_PIX_FMT_H264_SLICE looks pretty OK to me. > Also, VP8 uses > _FRAME to clearly indicate that it operates per-frame. > This is because VP8 doesn't have any concept of slices, the encoded unit is a video frame. > In addition, the _SLICE suffix is used by MPEG-2 in the stable API. Since we > certainly want MPEG-2 to allow per-slice and per-frame decoding as well as > H.264 and that the _SLICE format is specified to be the broken "concatenated > slices" that cedrus expects, we probably want to use another suffix. This way, > we could deprecated MPEG2_SLICE and introduce a new format for MPEG-2 that would > have consistent naming with the other mpeg formats. > > One suggestion I had was to call it H264_PARSED (and apply this to MPEG-2 and > HEVC when similar controls to H.264 are set in place for them). I think Hans had > another suggestion for the name but I don't recall what it was at this point. > > Either way, if this has to be some debate, we could perhaps take it off your > series and stay with SLICE_RAW for now, as long as we do rename it before making > the API stable. > > What do you think? > With the new pixel format modifiers (decode_mode and start_code), the _RAW suffix now has no meaning. Now, we could name it _PARSED or _SLICE. As long as this is properly documented (as it is now), that'd be fine. Now, to be completely honest, this discussion sounds like bikeshedding to me. Thanks, Eze