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=-8.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_PASS,URIBL_BLOCKED, USER_AGENT_NEOMUTT 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 B93F0C43381 for ; Thu, 14 Feb 2019 15:48:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 88589218FF for ; Thu, 14 Feb 2019 15:48:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2502234AbfBNPsD convert rfc822-to-8bit (ORCPT ); Thu, 14 Feb 2019 10:48:03 -0500 Received: from relay2-d.mail.gandi.net ([217.70.183.194]:42613 "EHLO relay2-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2502131AbfBNPsC (ORCPT ); Thu, 14 Feb 2019 10:48:02 -0500 X-Originating-IP: 90.88.30.68 Received: from localhost (aaubervilliers-681-1-89-68.w90-88.abo.wanadoo.fr [90.88.30.68]) (Authenticated sender: maxime.ripard@bootlin.com) by relay2-d.mail.gandi.net (Postfix) with ESMTPSA id A470940018; Thu, 14 Feb 2019 15:47:56 +0000 (UTC) Date: Thu, 14 Feb 2019 16:47:56 +0100 From: Maxime Ripard To: Ezequiel Garcia Cc: Tomasz Figa , Hans Verkuil , Alexandre Courbot , Sakari Ailus , Laurent Pinchart , Pawel Osciak , Paul Kocialkowski , Chen-Yu Tsai , Linux Kernel Mailing List , "list@263.net:IOMMU DRIVERS , Joerg Roedel ," , Linux Media Mailing List , Nicolas Dufresne , jenskuske@gmail.com, Jernej Skrabec , Jonas Karlman , linux-sunxi@googlegroups.com, Thomas Petazzoni Subject: Re: [PATCH v3 0/2] media: cedrus: Add H264 decoding support Message-ID: <20190214154756.iirejyrmqrtfjr3e@flea> References: <4a1346315224850faf31345b577ce3a29c069f3a.camel@collabora.com> <2e468fd22b577f1a5fd5d3186d6cc88e442e07ec.camel@collabora.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: 8BIT In-Reply-To: <2e468fd22b577f1a5fd5d3186d6cc88e442e07ec.camel@collabora.com> User-Agent: NeoMutt/20180716 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org On Wed, Feb 13, 2019 at 01:28:34PM -0300, Ezequiel Garcia wrote: > On Wed, 2019-02-13 at 12:02 +0900, Tomasz Figa wrote: > > On Wed, Feb 13, 2019 at 6:22 AM Ezequiel Garcia wrote: > > > Hey Tomasz, > > > > > > On Tue, 2019-02-12 at 21:50 +0900, Tomasz Figa wrote: > > > > Hi Maxime, > > > > > > > > On Mon, Feb 11, 2019 at 11:39 PM Maxime Ripard > > > > wrote: > > > > > Hi, > > > > > > > > > > Here is a new version of the H264 decoding support in the cedrus > > > > > driver. > > > > > > > > Thanks for working on this. Please see my comments below. > > > > > > > > > As you might already know, the cedrus driver relies on the Request > > > > > API, and is a reverse engineered driver for the video decoding engine > > > > > found on the Allwinner SoCs. > > > > > > > > > > This work has been possible thanks to the work done by the people > > > > > behind libvdpau-sunxi found here: > > > > > https://github.com/linux-sunxi/libvdpau-sunxi/ > > > > > > > > > > I've tested the various ABI using this gdb script: > > > > > http://code.bulix.org/jl4se4-505620?raw > > > > > > > > > > And this test script: > > > > > http://code.bulix.org/8zle4s-505623?raw > > > > > > > > > > The application compiled is quite trivial: > > > > > http://code.bulix.org/e34zp8-505624?raw > > > > > > > > > > The output is: > > > > > arm: builds/arm-test-v4l2-h264-structures > > > > > SHA1: 88cbf7485ba81831fc3b93772b215599b3b38318 > > > > > x86: builds/x86-test-v4l2-h264-structures > > > > > SHA1: 88cbf7485ba81831fc3b93772b215599b3b38318 > > > > > x64: builds/x64-test-v4l2-h264-structures > > > > > SHA1: 88cbf7485ba81831fc3b93772b215599b3b38318 > > > > > arm64: builds/arm64-test-v4l2-h264-structures > > > > > SHA1: 88cbf7485ba81831fc3b93772b215599b3b38318 > > > > > > > > > > Let me know if there's any flaw using that test setup, or if you have > > > > > any comments on the patches. > > > > > > > > > > Maxime > > > > > > > > > > Changes from v2: > > > > > - Simplified _cedrus_write_ref_list as suggested by Jernej > > > > > - Set whether the frame is used as reference using nal_ref_idc > > > > > - Respect chroma_format_idc > > > > > - Fixes for the scaling list and prediction tables > > > > > - Wrote the documentation for the flags > > > > > - Added a bunch of defines to the driver bit fields > > > > > - Reworded the controls and data format descriptions as suggested > > > > > by Hans > > > > > - Reworked the controls' structure field size to avoid padding > > > > > - Removed the long term reference flag > > > > > > > > This and... > > > > > > > > > > Maxime has dropped this because of Ayaka's mail about long term references > > > not making much sense in stateless decoders. > > > > I haven't seen any argument confirming that thesis, though. I should > > have kicked in earlier, sorry. > > > > OK, in that case, we need to have this flag back. > > > > I noticed that RK3399 TRM has a field to specify long term refs and > > > so was wondering about this item as well. > > > > > > > > - Reintroduced the neighbor info buffer > > > > > - Removed the ref_pic_list_p0/b0/b1 arrays that are redundant with the > > > > > one in the DPB > > > > > > > > these are used in our Rockchip VDEC driver. > > > > > > > > Could you elaborate on the reasons why they got removed? > > > > > > > > > > If I understood correctly, there are two reference picture lists. > > > P-frames will populate ref_pic_list0 and B-frames will populate both. > > > > > > According to this, v4l2_ctrl_h264_slice_param.ref_pic_list0 and .ref_pic_list1 > > > should be enough and ref_pic_list_p0/b0/b1 are not needed. > > > > > > What do you think? > > > > The lists in v4l2_ctrl_h264_slice_param are expected to be past the > > per-slice modification stage (which is quite complicated and better > > done in userspace), > > The fact that these are RefPicList0 and RefPicList1, after > the reordering stage should be better documented. > > > while the ones in v4l2_ctrl_h264_decode_param just > > in the original order. Rockchip VPU expects them in the original order > > and does the modification in the hardware. > > > > OK, I see. > > So, we have RefPicList0 and RefPicList1, and there is an initialization > stage and a modification/reordering process. > > One could argue that it's more generic to just pass the initial list, > but that would mean doing in the kernel something that is easier > done in userspace (and parsers doing this are already available). > > The question would be what is the most generic way of passing > the RefPicList0 and RefPicList1 in its initial state. > > 1/ We create additional controls for these. > > 2/ We put them on some of the other controls. Putting them on > v4l2_ctrl_h264_decode_param didn't seem too wrong. > > Any objections to put them back in there? None. i'll put them back in. Maxime -- Maxime Ripard, Bootlin Embedded Linux and Kernel engineering https://bootlin.com