From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org [79.124.17.100]) by master.gitmailbox.com (Postfix) with ESMTP id 90C3249855 for ; Thu, 21 Mar 2024 10:23:04 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id DFA8C68D53B; Thu, 21 Mar 2024 12:23:01 +0200 (EET) Received: from mail0.khirnov.net (red.khirnov.net [176.97.15.12]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id C86DD68D52A for ; Thu, 21 Mar 2024 12:22:55 +0200 (EET) Authentication-Results: mail0.khirnov.net; dkim=pass (2048-bit key; unprotected) header.d=khirnov.net header.i=@khirnov.net header.a=rsa-sha256 header.s=mail header.b=UyppsGUc; dkim-atps=neutral Received: from localhost (localhost [IPv6:::1]) by mail0.khirnov.net (Postfix) with ESMTP id 7BA58240DAC for ; Thu, 21 Mar 2024 11:22:55 +0100 (CET) Received: from mail0.khirnov.net ([IPv6:::1]) by localhost (mail0.khirnov.net [IPv6:::1]) (amavis, port 10024) with ESMTP id yyXZlNq4yUcH for ; Thu, 21 Mar 2024 11:22:54 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=khirnov.net; s=mail; t=1711016574; bh=Os8WF5oov6OmfujnrJGXlMBv92rPWdquUULSaUlVHbo=; h=Subject:From:To:In-Reply-To:References:Date:From; b=UyppsGUcuOWl43egVLX/H+tNAcr9VkG2TfTm79AVbafL+6Qq3xGcJoriw1byN7cgr xFgZeHc0o9aQe8gruEZpcS/9mFSzIhrY/SNZDP7PpVByhpaziJdhLq9YhofYLM9XdJ n/DPZj/bkXI/hmihwqImGdAujk/ndOeTyxcbAjEI0C2z7V/6FyoQNeGXxbIoipSg9p 8HCBRfFSHlOZjfYUiyARCcP+58XkG0bBiDMATNEV77w3UejSnjEhdPTEmiQbVfHPVo ANVBcD4oQgNxv94TCFgu5Nf9G2DWxd2UzfooNb3FdKJ6Elk+RAuwnnPOgpVFHFBrOn SetlxUVkt0PWg== Received: from lain.khirnov.net (lain.khirnov.net [IPv6:2001:67c:1138:4306::3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "lain.khirnov.net", Issuer "smtp.khirnov.net SMTP CA" (verified OK)) by mail0.khirnov.net (Postfix) with ESMTPS id DE3992404AF for ; Thu, 21 Mar 2024 11:22:54 +0100 (CET) Received: by lain.khirnov.net (Postfix, from userid 1000) id BB39F1601B9; Thu, 21 Mar 2024 11:22:54 +0100 (CET) From: Anton Khirnov To: FFmpeg development discussions and patches In-Reply-To: References: <20240313072725.7C7BA412605@natalya.videolan.org> <171041137125.7287.13066847473884265473@lain.khirnov.net> Mail-Followup-To: FFmpeg development discussions and patches Date: Thu, 21 Mar 2024 11:22:54 +0100 Message-ID: <171101657473.7287.12529372893895699228@lain.khirnov.net> User-Agent: alot/0.8.1 MIME-Version: 1.0 Subject: Re: [FFmpeg-devel] [FFmpeg-cvslog] fftools/ffmpeg: add loopback decoding X-BeenThere: ffmpeg-devel@ffmpeg.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: FFmpeg development discussions and patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: FFmpeg development discussions and patches Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: Quoting Gyan Doshi (2024-03-15 05:12:41) > > > On 2024-03-14 03:46 pm, Anton Khirnov wrote: > > Quoting Gyan Doshi (2024-03-13 08:49:52) > > > >> Are there any limitations to loopback decoding e.g. would a vpx w/alpha > >> encode be decoded back to a alpha pix fmt? > > I don't know how vpx alpha works, was it a separate stream in the > > demuxer or something like that? > > The encoder attaches the coded alpha as side data to the packet. Only a > couple of containers support this SD. > The demuxer, in turn, attaches the alpha as SD upon export. The packets arrive at the decoder exactly as the encoder produced them, so if that's enough then it should work. > > Loopback decoders work exactly like normal decoders, except their > > packets arrive from an encoder instead of a demuxer. > In terms of syntax, do all LB streams have to be specified in the first > output? Actually they are not a part of the output, they form their own parsing unit equivalent to -i/output. Probably this could be documented better. > Does that output muxer have to be null, or can those packets be > routed to both output and LB? The muxer can be anything, it does not know anything about loopback decoders. The only limitation in this regard is that it is not (currently) possible to avoid muxing entirely. -- Anton Khirnov _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".