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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,UNPARSEABLE_RELAY 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 BA01FC282C4 for ; Tue, 12 Feb 2019 21:18:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 830182081B for ; Tue, 12 Feb 2019 21:18:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732413AbfBLVSH (ORCPT ); Tue, 12 Feb 2019 16:18:07 -0500 Received: from bhuna.collabora.co.uk ([46.235.227.227]:43658 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727932AbfBLVSG (ORCPT ); Tue, 12 Feb 2019 16:18:06 -0500 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: ezequiel) with ESMTPSA id 20B0327FB65 Message-ID: Subject: Re: [PATCH v3 1/2] media: uapi: Add H264 low-level decoder API compound controls. From: Ezequiel Garcia To: Maxime Ripard , Hans Verkuil Cc: hans.verkuil@cisco.com, acourbot@chromium.org, sakari.ailus@linux.intel.com, Laurent Pinchart , tfiga@chromium.org, posciak@chromium.org, Paul Kocialkowski , Chen-Yu Tsai , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-media@vger.kernel.org, nicolas.dufresne@collabora.com, jenskuske@gmail.com, jernej.skrabec@gmail.com, jonas@kwiboo.se, linux-sunxi@googlegroups.com, Thomas Petazzoni , Guenter Roeck Date: Tue, 12 Feb 2019 18:17:52 -0300 In-Reply-To: <20190212130548.tytlxmbu4q6qgzzq@flea> References: <562aefcd53a1a30d034e97f177096d70fb705f2b.1549895062.git-series.maxime.ripard@bootlin.com> <716ae1ff-8e62-c723-5b5a-0b018cf6af6a@xs4all.nl> <20190212130548.tytlxmbu4q6qgzzq@flea> Organization: Collabora Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.30.5-1 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 Tue, 2019-02-12 at 14:05 +0100, Maxime Ripard wrote: > Hi, > > On Mon, Feb 11, 2019 at 04:21:47PM +0100, Hans Verkuil wrote: > > > I think the API should be designed with 4k video in mind. So if some of > > > these constants would be too small when dealing with 4k (even if the > > > current HW doesn't support this yet), then these constants would have to > > > be increased. > > > > > > And yes, I know 8k video is starting to appear, but I think it is OK > > > that additional control(s) would be needed to support 8k. > > > > Hmm, 4k (and up) is much more likely to use HEVC. So perhaps designing this > > for 4k is overkill. > > > > Does anyone know if H.264 is used for 4k video at all? If not (or if very > > rare), then just ignore this. > > I don't know the state of it right now, but until quite recently > youtube at least was encoding their 4k videos in both VP9 and > H264. They might have moved to h265 since, but considering 4k doesn't > seem unreasonable. > Just asked the multimedia team here, and they say that 4k videos are in fact widely used for both H264 and VP9 because of the HEVC licensing issues, and because gains in compressions are not so impressive. Regards, Ezequiel