From patchwork Sat Mar 26 21:39:26 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Sebastian Fricke X-Patchwork-Id: 12792688 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 46A1AC433F5 for ; Sat, 26 Mar 2022 21:39:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235496AbiCZVl2 (ORCPT ); Sat, 26 Mar 2022 17:41:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40782 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235507AbiCZVlZ (ORCPT ); Sat, 26 Mar 2022 17:41:25 -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 1904E647A; Sat, 26 Mar 2022 14:39:48 -0700 (PDT) Received: from localhost (unknown [IPv6:2a02:3030:b:56bb:fa6d:7c35:3706:d2b9]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: sebastianfricke) by bhuna.collabora.co.uk (Postfix) with ESMTPSA id 787CA1F44384; Sat, 26 Mar 2022 21:39:46 +0000 (GMT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1648330786; bh=F1dL3cnXKmAu6Uh9VDcqP6Zx5+Do8cHpp5UctZ443fM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ojUiBLj0Na7MmMoDpmsO5E89JcWI4z60KK0UHE7q9Z2apkPnVKHnkIlApHNM35O3H 3aw+EucxSefUltpMK1uClEHFHltRzn58xV3I5hVkjH8Skv4s4eHdi4aDhvS2W8rrAn tmryxI/CmKJo5ngKnODz0T+fNLzTPZN4P4/6XpLEMUt5jgJS8Ak7qNgPOjtkUHLu63 NyAZmW5qoBDj8zrCXU9r82Oo/Kfigyr49JlCV26/Bpyg4wJMG9DLSRIMr5VCBLF23c XNNhO3qlmQfdtva1wkDUXX7IaBz/eBAeRvBOJhuDTi4P0rNptraLup4iaQzZ1MEPIE eL/0xcmjohyNQ== 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 v2 1/2] media: docs-rst: Append HEVC specific term Date: Sat, 26 Mar 2022 22:39:26 +0100 Message-Id: <20220326213927.103680-2-sebastian.fricke@collabora.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220326213927.103680-1-sebastian.fricke@collabora.com> References: <20220326213927.103680-1-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 --- 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