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 6DBC0435DA for ; Thu, 17 Nov 2022 07:32:21 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 3DFAC68BA62; Thu, 17 Nov 2022 09:32:20 +0200 (EET) Received: from mx.sdf.org (mx.sdf.org [205.166.94.24]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id ECE8A68B371 for ; Thu, 17 Nov 2022 09:32:13 +0200 (EET) Received: from 4eb231a0d1b36cedda43a2a005befe4d ([1.152.240.1]) (authenticated (0 bits)) by mx.sdf.org (8.15.2/8.14.5) with ESMTPSA id 2AH7W7xR024406 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256 bits) verified NO) for ; Thu, 17 Nov 2022 07:32:11 GMT Date: Thu, 17 Nov 2022 18:32:03 +1100 From: Peter Ross To: FFmpeg development discussions and patches Message-ID: Mail-Followup-To: FFmpeg development discussions and patches References: <20221113184441.1741-1-cus@passwd.hu> <20221113184441.1741-3-cus@passwd.hu> <166844365819.20155.3362908166990565436@lain.khirnov.net> <362f6c69-b72d-447-7ab5-4a24695c58c8@passwd.hu> MIME-Version: 1.0 In-Reply-To: <362f6c69-b72d-447-7ab5-4a24695c58c8@passwd.hu> Subject: Re: [FFmpeg-devel] [PATCH 3/3] avformat/electronicarts: add option to return alpha channel in the main video stream in VP6A codec 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="===============5979692993788773914==" Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: --===============5979692993788773914== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="8khYlog9AMtWdy6Q" Content-Disposition: inline --8khYlog9AMtWdy6Q Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Nov 14, 2022 at 11:05:44PM +0100, Marton Balint wrote: >=20 >=20 > On Mon, 14 Nov 2022, Anton Khirnov wrote: >=20 > > Quoting Marton Balint (2022-11-13 19:44:41) > > > Signed-off-by: Marton Balint > > > --- > > > doc/demuxers.texi | 18 ++++++++++++++++ > > > libavformat/electronicarts.c | 42 +++++++++++++++++++++++++++++++---= -- > > > libavformat/version.h | 2 +- > > > 3 files changed, 56 insertions(+), 6 deletions(-) > > >=20 > > > diff --git a/doc/demuxers.texi b/doc/demuxers.texi > > > index 2b6dd86c2a..f07f3f5318 100644 > > > --- a/doc/demuxers.texi > > > +++ b/doc/demuxers.texi > > > @@ -285,6 +285,24 @@ This demuxer accepts the following option: > > >=20 > > > @end table > > >=20 > > > +@section ea > > > + > > > +Electronic Arts Multimedia format demuxer. > > > + > > > +This format is used by various Electronic Arts games. > > > + > > > +@subsection Options > > > + > > > +@table @option > > > + > > > +@item merge_alpha @var{bool} > > > + > > > +Normally the VP6 alpha channel (if exists) is returned as a secondar= y video > > > +stream, > >=20 > > Why? And why keep it as the default? >=20 > VP6 alpha in EA format is a second VP6 encoded video stream where only th= e Y > component is used and is interpreted as the alpha channel of the first VP6 > stream. The alpha VP6 stream is muxed separately from the main VP6 stream, > has its own stream headers and packet headers. In theory the two streams > might not even have the same resolution (although most likely that is not > something that is seen or supported in the wild), but the format is capab= le > of doing it. >=20 > Merged VP6 alpha (also known as the VP6A codec) means that a packet of the > video stream contains the corresponding packet of both VP6 substreams like > this: > {OffsetOfAlpha, DataPacket, AlphaDataPacet} > So data and alpha data of a frame is merged to a single packet, this is h= ow > VP6 video with alpha is muxed in FLV and SWF. >=20 > So the first approach is more like how the demuxer sees data in the EA > format, unfortunately it is different to what the FLV or SWF format expec= ts, > so - having no better place for it in the framework - I decided to do an > optional format conversion in the EA demuxer. >=20 > I did not want to change the default, but certainly doable if people pref= er > it. looks good. i have no preference. -- Peter (A907 E02F A6E5 0CD2 34CD 20D2 6760 79C5 AC40 DD6B) --8khYlog9AMtWdy6Q Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iF0EABECAB0WIQSpB+AvpuUM0jTNINJnYHnFrEDdawUCY3XjcwAKCRBnYHnFrEDd a7DZAJwLy5qswhklUHhQ/zMTFABJevcRvQCfYoyKDgXVg1s2Bj71xoR/wKJRS5A= =rhy6 -----END PGP SIGNATURE----- --8khYlog9AMtWdy6Q-- --===============5979692993788773914== 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". --===============5979692993788773914==--