From patchwork Tue Mar 29 06:56:56 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Sebastian Fricke X-Patchwork-Id: 12794483 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 C36F4C433F5 for ; Tue, 29 Mar 2022 06:57:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233225AbiC2G7Q (ORCPT ); Tue, 29 Mar 2022 02:59:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36622 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231715AbiC2G7O (ORCPT ); Tue, 29 Mar 2022 02:59:14 -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 D54202ED50; Mon, 28 Mar 2022 23:57:30 -0700 (PDT) Received: from localhost (unknown [IPv6:2a02:3030:a:f397:f6bc:b726:2678:839f]) (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 2BF361F43635; Tue, 29 Mar 2022 07:57:29 +0100 (BST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1648537049; bh=szOBLpLdwQa32D4Bqsi6fFyIDa3A9/cqpY4tz/Nklrg=; h=From:To:Cc:Subject:Date:From; b=BZuw1pQbc6RTFxE4WEZdiGXaQvWl4IjCDX2u0NUtPgKIQqjCWu9rrTazFkSYNn2gr rChbXY4UGnlOVwX8+5YN4wSwCbtz5K/Qp/64K3vmZ9EhOTVQwzGaW2rDC5uAxo5mAs nSmqNNiEhfsl/30adAsMXAhJc63KRG1YQ78ER/6byhknvusLVxTxjUO6cQIKJVQkd4 vRRSeIr/FWDxEZREK/L3hmP+9FYHojFWJoJ5ikzHM7d7lg7YtK/JJHGgJ4/xogB4kB 4B1xcyFfOvE4grOXmtm3sePfD7zCsHOO/oZ5F+zkfpYZTYb31/juyxyyfLtTi4J6dt oeBKojLYyn9jw== From: Sebastian Fricke To: linux-media@vger.kernel.org Cc: Sebastian Fricke , Jernej Skrabec , Mauro Carvalho Chehab , Tomasz Figa , Alexandre Courbot , Hans Verkuil , linux-kernel@vger.kernel.org (open list) Subject: [PATCH] media: docs-rst: Append HEVC specific term Date: Tue, 29 Mar 2022 08:56:56 +0200 Message-Id: <20220329065657.8509-1-sebastian.fricke@collabora.com> X-Mailer: git-send-email 2.25.1 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