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=-4.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,URIBL_BLOCKED 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 BB5E8C433DF for ; Thu, 30 Jul 2020 13:48:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A1D9322BF5 for ; Thu, 30 Jul 2020 13:48:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728389AbgG3NsI (ORCPT ); Thu, 30 Jul 2020 09:48:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48854 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726281AbgG3NsH (ORCPT ); Thu, 30 Jul 2020 09:48:07 -0400 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 86646C061574; Thu, 30 Jul 2020 06:48:07 -0700 (PDT) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: nicolas) with ESMTPSA id 652012948B5 Message-ID: <74dbf137d8838967c6e1433463b2af708be4da03.camel@collabora.com> Subject: Re: [PATCH 03/10] media: uapi: h264: Split prediction weight parameters From: Nicolas Dufresne Reply-To: Nicolas Dufresne To: Alexandre Courbot , Ezequiel Garcia Cc: Linux Media Mailing List , LKML , Tomasz Figa , kernel@collabora.com, Jonas Karlman , Hans Verkuil , Jeffrey Kardatzke , Philipp Zabel , Maxime Ripard , Paul Kocialkowski Date: Thu, 30 Jul 2020 09:48:01 -0400 In-Reply-To: References: <20200715202233.185680-1-ezequiel@collabora.com> <20200715202233.185680-4-ezequiel@collabora.com> Organization: Collabora Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="=-wiNEtf151ipqvNyTRQIL" User-Agent: Evolution 3.36.3 (3.36.3-1.fc32) MIME-Version: 1.0 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org --=-wiNEtf151ipqvNyTRQIL Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Le samedi 25 juillet 2020 =C3=A0 22:30 +0900, Alexandre Courbot a =C3=A9cri= t : > On Thu, Jul 16, 2020 at 5:23 AM Ezequiel Garcia = wrote: > > The prediction weight parameters are only required under > > certain conditions, which depend on slice header parameters. > >=20 > > The slice header syntax specifies that the prediction > > weight table is present if: > >=20 > > ((weighted_pred_flag && (slice_type =3D=3D P || slice_type =3D=3D SP)) = || \ > > (weighted_bipred_idc =3D=3D 1 && slice_type =3D=3D B)) >=20 > This is a pretty important bit - how about mentioning in the documentatio= n when > this new control is expected to be present, so both drivers and > userspace submit it > or omit it in a consistent manner? This is copy paste from the spec. We can add a reference to the syntax chapter in the spec that express exactly this if condition (syntax is express in pseudo code). The bitstream works exactly the same. Note that it's not a fault to provide the control even if not needed, drivers will kindly ignore it. Reference: 7.3.3 Slice header syntax Nicolas --=-wiNEtf151ipqvNyTRQIL Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- iF0EABECAB0WIQSScpfJiL+hb5vvd45xUwItrAaoHAUCXyLPkQAKCRBxUwItrAao HDL8AKCtSvcMrSUmQXK5ljp++0GzWttLYwCfclTwQk9ZR4oVP+PZbA3QNpTHNOA= =K+qX -----END PGP SIGNATURE----- --=-wiNEtf151ipqvNyTRQIL--