From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ffbox0-bg.ffmpeg.org (ffbox0-bg.ffmpeg.org [79.124.17.100]) by master.gitmailbox.com (Postfix) with ESMTPS id ABE8C4C760 for ; Tue, 5 Aug 2025 08:58:34 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.ffmpeg.org (Postfix) with ESMTP id 36F0168C25D; Tue, 5 Aug 2025 11:58:30 +0300 (EEST) Received: from mail-ed1-f54.google.com (mail-ed1-f54.google.com [209.85.208.54]) by ffbox0-bg.ffmpeg.org (Postfix) with ESMTPS id 38048687CA9 for ; Tue, 5 Aug 2025 11:58:24 +0300 (EEST) Received: by mail-ed1-f54.google.com with SMTP id 4fb4d7f45d1cf-61571192c3aso5404634a12.2 for ; Tue, 05 Aug 2025 01:58:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nxtedition.com; s=google; t=1754384303; x=1754989103; darn=ffmpeg.org; h=to:subject:message-id:date:from:in-reply-to:references:mime-version :from:to:cc:subject:date:message-id:reply-to; bh=1DPhbIvuSfgvG769fZhO7I1dVpEi/pGfhCpmmklb4I8=; b=yFcWvPeIsFths81/SgD9S6KYiDEjXiWvkCGhhBuWp6MVGHKHie/6lA5u0ElSIl2BtC EIWc8/ZNZPh85xQhHpRLtIRyLKj9h4qMWOadIEJNp9CT+0pfBck12MxTIiTVUaWaVrRo AyKULltWBl66C9Q0CQhGPUND+e757aO6CjTk1e9PbURVkQEbGY5z2lfqfYyAbs19MuDz OuAAbFD1M3BnFmpis5/xfbVVLjPzfLNPMbuiaOTEyhE30uo5dyaa6bhb9k8akIhmcKH7 FZia8hgdzR9zF+yxIcuSAY4YnGYoOuJErhX13M1aHHXt5K1Hy4nWKjZyVby+OlP5MIdw eFpA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1754384303; x=1754989103; h=to:subject:message-id:date:from:in-reply-to:references:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=1DPhbIvuSfgvG769fZhO7I1dVpEi/pGfhCpmmklb4I8=; b=mNRB5VogVkNcdlxtGObhJ8BcPaa1zpwliFCUgFls6BwSRGm+2alABbeZCYzOOhg10n B9gfdSx4mGZTYnl1Evsr6Sof/qfojvPfIJZ/6QAcm/1BkxDJFhEn1jWC1T5RIuuoAqdJ QxIG44zDbLJTr0Cj0Ggy+u5+QO8f/qABme7w/EDqHrtE+uXg7VcWxthaDU8EbimdeKBH Y8tx5VHfXyMuxcgE69pr8nc5/aybp4rUISH69oVbxnjfoelIfTkFCyAqQCp3IpUndgVJ IaX3aXALspbvC1/JN+nlIGd3XVAsoSiH5QXrRfv4SP/F0TFajzSDEZ6mpGCK3D1XhNhY T++g== X-Gm-Message-State: AOJu0YxSsbmNynglr5QitJRib8B2lybq1H09Rg3WdY3BuQ0965eWUD2z rhpcd3wf7n4egT2sVbAMilyFy9yIoVmw4C1CPVYUgoBGvq+2GaHvV50YO1qdItJLHRH8TtbYxRO 7WSqCh8NV2jrNcYZC5smvAIJO7fk0pX72UPhNOAULSoApMwNtExIarw== X-Gm-Gg: ASbGncslxjP+/akiLG9edz2xD/+WAh3ya6sK57Si9J4T6K0RpqwwPfn/pU1e5yRaNY4 aWOyMlTjLGEVOdKLHsHIqPzUzKe4X8m/07pmesyyByqj2dJKpQle27iWLJFcnxTLzsbfl0rhV6W BqzR/6Arr4HBZ1YxgVSeUU7BtU2vOV8NEzBF12RL4ddj76XyB253lizRDBibhwXRirrugM3CDw4 cAIn2sFNbRhKdnA X-Google-Smtp-Source: AGHT+IFQ/ET7CywtpWextSeftnN63G6XRvZbf3iGyjZU/JTggIDwYYLHSPuOAmCVwgQr8G7uK1qaN7FqDCuNN/p2HF4= X-Received: by 2002:a17:906:478c:b0:ae9:c2b9:7eba with SMTP id a640c23a62f3a-af940044e2dmr1190274566b.24.1754384303053; Tue, 05 Aug 2025 01:58:23 -0700 (PDT) MIME-Version: 1.0 References: <20250803125028.GD4581@haasn.xyz> <20250803124237.GB4581@haasn.xyz> <20250805105119.GD219179@haasn.xyz> In-Reply-To: <20250805105119.GD219179@haasn.xyz> From: Robert Nagy Date: Tue, 5 Aug 2025 10:58:12 +0200 X-Gm-Features: Ac12FXy80fhW2DqFiGgleE48qNl0QZooUCrg34kp_8F1yUNknmraH4NybiRQZYw Message-ID: To: FFmpeg development discussions and patches Subject: Re: [FFmpeg-devel] [PATCH] lavfi: protection against premultiplied alpha (was: The patch series about premultiplied alpha) 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: Just wanted to clarify that this feature is not just academic but something that is quite important for broadcasters where we often receive/send content of mixed alpha type. Users often don't know the difference between the alpha type and send material in whatever mode their editing software happens to use. During playout premultiplied alpha has become much more common. Especially since often output from e.g. Chrome is used during composition (which is premultiplied) and newer video switchers seem to move towards premultiplied. While more traditional workflows use straight alpha. Hence we often end up with a mix we need to somehow handle. In our use case we try to guess the alpha mode with the "colordetect" filter and/or let the users explicitly set the alpha mode and then we forward that using setparams. Without this feature it is difficult and/or inefficient to get composition using e.g. vf_overlay or vf_libplacebo working well. -- Robert _______________________________________________ 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".