From patchwork Sun Mar 27 08:43:08 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Sebastian Fricke X-Patchwork-Id: 12792770 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2A5E0C433EF for ; Sun, 27 Mar 2022 08:44:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231194AbiC0Iqd (ORCPT ); Sun, 27 Mar 2022 04:46:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42360 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230229AbiC0Iqc (ORCPT ); Sun, 27 Mar 2022 04:46:32 -0400 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [46.235.227.227]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A4C91B3; Sun, 27 Mar 2022 01:44:54 -0700 (PDT) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: sebastianfricke) with ESMTPSA id BF4CE1F43B72 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1648370693; bh=F1dL3cnXKmAu6Uh9VDcqP6Zx5+Do8cHpp5UctZ443fM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KnH+U2zZXV6Zg/EsRrMfFDPIdf6I5V1yBs4cOngTwiDQM0g3CbGKrmuGpDoyxzxPw pcFaEtW8Lgv42KL5+EQCKHZMRNl2hVlmyAEAwVVgBw6oI5e7ZzooDe/Hk207PWQbeq BtdIAN8cpkS/Tdq4ECN0xLY+WfgRe5pYHoz5EIQ/t4C7BmI3ccCp60JjAowejnJuFk edePFLyNlCvIfeIEwdF18huLRkBzP+0bhUPFoAK+GDlmTSyFMyZS9ybTkW4Xnad2/3 /G29T/c9My6BsUyw1TOdI+ExY8meXxZHPSKUSBEM0hQig6bki/av0stLjTqfrkkQtX bfNILFVWtYh0A== From: Sebastian Fricke To: linux-media@vger.kernel.org Cc: acourbot@chromium.org, tfiga@chromium.org, hverkuil-cisco@xs4all.nl, Sebastian Fricke , Mauro Carvalho Chehab , Maxime Ripard , Paul Kocialkowski , Greg Kroah-Hartman , Chen-Yu Tsai , Jernej Skrabec , linux-kernel@vger.kernel.org (open list), linux-staging@lists.linux.dev (open list:STAGING SUBSYSTEM), linux-arm-kernel@lists.infradead.org (moderated list:ARM/Allwinner sunXi SoC support), linux-sunxi@lists.linux.dev (open list:ARM/Allwinner sunXi SoC support) Subject: [RFC PATCH v3 1/2] media: docs-rst: Append HEVC specific term Date: Sun, 27 Mar 2022 10:43:08 +0200 Message-Id: <20220327084308.9053-2-sebastian.fricke@collabora.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220327084308.9053-1-sebastian.fricke@collabora.com> References: <20220327084308.9053-1-sebastian.fricke@collabora.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Describe the coding tree unit as replacement for the macroblock in the HEVC codec. Highlight a key difference of the HEVC codec to predecessors like AVC(H.264) to give a better overview of the differences between the coding standards. Signed-off-by: Sebastian Fricke Acked-by: Jernej Skrabec --- Documentation/userspace-api/media/v4l/dev-decoder.rst | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/Documentation/userspace-api/media/v4l/dev-decoder.rst b/Documentation/userspace-api/media/v4l/dev-decoder.rst index 3cf2b496f2d0..eb5b1b1e3a51 100644 --- a/Documentation/userspace-api/media/v4l/dev-decoder.rst +++ b/Documentation/userspace-api/media/v4l/dev-decoder.rst @@ -72,6 +72,11 @@ coded resolution coded width width for given coded resolution. +coding tree unit + processing unit of the HEVC codec (≘ macroblock units in H.264, VP8, VP9); + can use block structures of up to 64×64 pixels; + Good at sub-partitioning the picture into variable sized structures. + decode order the order in which frames are decoded; may differ from display order if the coded format includes a feature of frame reordering; for decoders, @@ -104,7 +109,8 @@ keyframe macroblock a processing unit in image and video compression formats based on linear block transforms (e.g. H.264, VP8, VP9); codec-specific, but for most of - popular codecs the size is 16x16 samples (pixels). + popular codecs the size is 16x16 samples (pixels). The HEVC codec uses a + slightly more flexible processing unit called coding tree unit (CTU). OUTPUT the source buffer queue; for decoders, the queue of buffers containing