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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 78A03C10F14 for ; Thu, 3 Oct 2019 21:12:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 529A92133F for ; Thu, 3 Oct 2019 21:12:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730663AbfJCVMv (ORCPT ); Thu, 3 Oct 2019 17:12:51 -0400 Received: from relay8-d.mail.gandi.net ([217.70.183.201]:36919 "EHLO relay8-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727789AbfJCVMv (ORCPT ); Thu, 3 Oct 2019 17:12:51 -0400 X-Originating-IP: 132.205.230.8 Received: from aptenodytes (unknown [132.205.230.8]) (Authenticated sender: paul.kocialkowski@bootlin.com) by relay8-d.mail.gandi.net (Postfix) with ESMTPSA id 570951BF204; Thu, 3 Oct 2019 21:12:48 +0000 (UTC) Date: Thu, 3 Oct 2019 17:12:47 -0400 From: Paul Kocialkowski To: Philipp Zabel Cc: linux-media@vger.kernel.org, Tomasz Figa , Hans Verkuil , Ezequiel Garcia , Boris Brezillon , kernel@pengutronix.de Subject: Re: [PATCH] media: uapi: h264: clarify num_ref_idx_l[01]_(default_)active fields Message-ID: <20191003211247.GC3927@aptenodytes> References: <20190905114210.9232-1-p.zabel@pengutronix.de> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="B4IIlcmfBL/1gGOG" Content-Disposition: inline In-Reply-To: <20190905114210.9232-1-p.zabel@pengutronix.de> User-Agent: Mutt/1.12.2 (2019-09-21) Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org --B4IIlcmfBL/1gGOG Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, On Thu 05 Sep 19, 13:42, Philipp Zabel wrote: > To explain why num_ref_idx_active_override_flag is not part of the API, > describe how the num_ref_idx_l[01]_active_minus1 fields and the > num_ref_idx_l[01]_default_active_minus1 fields are used, depending on > whether the decoder parses slice headers itself or not. Is there any particular reason why this is preferable to exposing the flag? It feels like having the flag around sticks closer to the bitstream, so it's more straightforward for everyone. In case there's only one set of fields exposed by the hardware (and it does= n't do slice parsing itself), we could always check the flag in the driver and = use either the default PPS values or the slice-specific values there. What do you think? Cheers, Paul > Signed-off-by: Philipp Zabel > --- > Documentation/media/uapi/v4l/ext-ctrls-codec.rst | 12 ++++++++---- > 1 file changed, 8 insertions(+), 4 deletions(-) >=20 > diff --git a/Documentation/media/uapi/v4l/ext-ctrls-codec.rst b/Documenta= tion/media/uapi/v4l/ext-ctrls-codec.rst > index bc5dd8e76567..b9834625a939 100644 > --- a/Documentation/media/uapi/v4l/ext-ctrls-codec.rst > +++ b/Documentation/media/uapi/v4l/ext-ctrls-codec.rst > @@ -1630,10 +1630,10 @@ enum v4l2_mpeg_video_h264_hierarchical_coding_typ= e - > - > * - __u8 > - ``num_ref_idx_l0_default_active_minus1`` > - - > + - This field is only used by decoders that parse slices themselves. > * - __u8 > - ``num_ref_idx_l1_default_active_minus1`` > - - > + - This field is only used by decoders that parse slices themselves. > * - __u8 > - ``weighted_bipred_idc`` > - > @@ -1820,10 +1820,14 @@ enum v4l2_mpeg_video_h264_hierarchical_coding_typ= e - > - > * - __u8 > - ``num_ref_idx_l0_active_minus1`` > - - > + - This field is used by decoders that do not parse slices themselv= es. > + If num_ref_idx_active_override_flag is not set, this field must = be > + set to the value of num_ref_idx_l0_default_active_minus1. > * - __u8 > - ``num_ref_idx_l1_active_minus1`` > - - > + - This field is used by decoders that do not parse slices themselv= es. > + If num_ref_idx_active_override_flag is not set, this field must = be > + set to the value of num_ref_idx_l1_default_active_minus1. > * - __u32 > - ``slice_group_change_cycle`` > - > --=20 > 2.20.1 >=20 --=20 Paul Kocialkowski, Bootlin Embedded Linux and kernel engineering https://bootlin.com --B4IIlcmfBL/1gGOG Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEJZpWjZeIetVBefti3cLmz3+fv9EFAl2WZE4ACgkQ3cLmz3+f v9EXiggAgWSMnZVKRXXi9LlaAxNxxP/DETQ9Wb+SluPPCqU/HTosI3y1oI9eBfXK 76/JuTVM+TlyrKt4H8+5qdBZ6MbxNAyHvHvGFM74XmQ80edJV8fpARtbIT+iOw6q tE2XblpPIbtrX/LSLNe878+vnR8c7cQPBnaQFpyK09bZVzcBqhQRD9Hj/o2Fl33a OiUl1xl13IgMeOeMMTT/9gZ7rxVX1f3/R1LajBMOYs1XAy5O0vG3TDB+8fuStq2C 2t6Atew5ual/HSPzrdP2xQmXTb+DTo2n/nKcr1VbiSm82RMhkJapKO9XJiwcdqu/ WbVWQGvEBnXLyJ7S/CvL5w0Q+25kBQ== =ngGV -----END PGP SIGNATURE----- --B4IIlcmfBL/1gGOG--