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 B66A84BF51 for ; Mon, 28 Jul 2025 00:00:41 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.ffmpeg.org (Postfix) with ESMTP id 3B95A68D404; Mon, 28 Jul 2025 03:00:37 +0300 (EEST) Received: from relay9-d.mail.gandi.net (relay9-d.mail.gandi.net [217.70.183.199]) by ffbox0-bg.ffmpeg.org (Postfix) with ESMTPS id 3F0E468C9FE for ; Mon, 28 Jul 2025 03:00:30 +0300 (EEST) Received: by mail.gandi.net (Postfix) with ESMTPSA id 5F65343256 for ; Mon, 28 Jul 2025 00:00:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=niedermayer.cc; s=gm1; t=1753660829; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Lm2EVs+NK4mIQ8bYLmLEJk3vs3WNyNFNoHEc/S9UYGo=; b=SkqVVBUiD3wv0EYAuLAFSC+hhiQs058FkoxaowXfz1GX68ItvJvenZKDoOUO45e+Oxc3b3 b33xi1PNdBm3eSZ/VjUBUtNDWbc/eG18ozZ+w1c4o3zqX3NKGNzoKNCW4rNS0IFKFyjMfp fGMf/Mdn2ZfG3k0R+UO4pFqgxjVD+feVMmV98jeRFTc05/0o9txid3AcD4D8NzH/IN8hif r31ECnOY4Cu+XaIINo2lgKDJxxJhqPmoJi/02ZvBAJZVQQlDhrDTiPSoqdZOEwjmY6UE5p BthbMZtDiUrlkCPJHi5YGN6U9+nzw1SFrHT1Id9iqXfW5HM6XGFtlU598hPbaQ== Date: Mon, 28 Jul 2025 02:00:28 +0200 From: Michael Niedermayer To: FFmpeg development discussions and patches Message-ID: <20250728000028.GW29660@pb2> References: <20250723135626.1390296-1-ffmpeg@haasn.xyz> <20250723171838.GB1401694@haasn.xyz> <20250724131154.GB95314@haasn.xyz> MIME-Version: 1.0 In-Reply-To: <20250724131154.GB95314@haasn.xyz> X-GND-State: clean X-GND-Score: -85 X-GND-Cause: gggruggvucftvghtrhhoucdtuddrgeeffedrtdefgdeltdeijecutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfitefpfffkpdcuggftfghnshhusghstghrihgsvgenuceurghilhhouhhtmecufedtudenucesvcftvggtihhpihgvnhhtshculddquddttddmnegfrhhlucfvnfffucdludehmdenucfjughrpeffhffvuffkfhggtggujgesghdtreertddtvdenucfhrhhomhepofhitghhrggvlhcupfhivgguvghrmhgrhigvrhcuoehmihgthhgrvghlsehnihgvuggvrhhmrgihvghrrdgttgeqnecuggftrfgrthhtvghrnhepieegkedtjeduffejhfetgeejtdegteetgfegtdfhjefgvefhteegkeejtddvhfevnecukfhppeeguddrieeirdeihedrudejieenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepihhnvghtpeeguddrieeirdeihedrudejiedphhgvlhhopehlohgtrghlhhhoshhtpdhmrghilhhfrhhomhepmhhitghhrggvlhesnhhivgguvghrmhgrhigvrhdrtggtpdhnsggprhgtphhtthhopedupdhrtghpthhtohepfhhfmhhpvghgqdguvghvvghlsehffhhmphgvghdrohhrgh X-GND-Sasl: michael@niedermayer.cc Subject: Re: [FFmpeg-devel] Again pre-multiplied 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: multipart/mixed; boundary="===============0763898716630778711==" Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: --===============0763898716630778711== Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="WZJyhX63VJL+5o8l" Content-Disposition: inline --WZJyhX63VJL+5o8l Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi Niklas On Thu, Jul 24, 2025 at 01:11:54PM +0200, Niklas Haas wrote: > On Wed, 23 Jul 2025 19:02:06 +0200 Nicolas George wrote: > > Niklas Haas (HE12025-07-23): > > > [PATCH v2 05/18] avcodec/encode: enforce alpha mode compatibility at = encode time > > > > That handles it for encoders, I suppose. But I do not see anything > > protecting you from stacking images with different kind of alpha or > > sending this kind of frames to a muxer with uncoded frames. >=20 > That is no worse than the status quo, so I fail to see how this patch is > a regression in this regard. >=20 > That aside, there is also not anything preventing you from doing the same > for images with a different chroma sample location, or different HDR meta= data, > or different sample aspect ratios, or any of the other oodles of properti= es > (including arbitrarily extensible frame side data) that are not currently > participating in libavfilter format negotiation. >=20 > In a perfect world, we would have automatic format negotiation for every > AVFrame property; but as it stands, the libavfilter code is too obnoxious, > brittle and inflexible to permit such while remaining sane. While redesig= ning > libavfilter to make it more extensible would certainly be a useful exerci= se > (perhaps a good STF 2025 candidate?), I think that rather exceeds the sco= pe > of this patchset. About STF, it depends on who does the work. If a FFmpeg developer does the work, then i think STF is a good idea. OTOH It would be an inappropriate task for a new contributor (like in GSoC). One thing thats important for this is that whoever wants to work on this speaks with Nicolas to make sure theres agreement on the implementation. Because i belive everyone of us has a different idea how to implement this. My original plan was based on arbitrary graphs and a solution that could be proofen to be within a constant factor of the global optimum. This would have required simplifying the graph iteratively with a random seed multiple times IIRC. But because a single pass "just worked" i never implemented thi= s. thx [...] --=20 Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB Democracy is the form of government in which you can choose your dictator --WZJyhX63VJL+5o8l Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iF0EABEKAB0WIQSf8hKLFH72cwut8TNhHseHBAsPqwUCaIa9mAAKCRBhHseHBAsP q95xAJ4mu80CPEdkB4FxupLSwBb908LEAwCbB/PEfzxSjNqVwFWM7RXsQ991qi4= =uzHQ -----END PGP SIGNATURE----- --WZJyhX63VJL+5o8l-- --===============0763898716630778711== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ 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". --===============0763898716630778711==--