From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) by finch.gentoo.org (Postfix) with ESMTP id E0A7A138237 for ; Wed, 2 Jan 2013 00:47:43 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 4053F21C040; Wed, 2 Jan 2013 00:47:20 +0000 (UTC) Received: from mail-ob0-f179.google.com (mail-ob0-f179.google.com [209.85.214.179]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id 88DA821C025 for ; Wed, 2 Jan 2013 00:46:00 +0000 (UTC) Received: by mail-ob0-f179.google.com with SMTP id x4so12268317obh.24 for ; Tue, 01 Jan 2013 16:45:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=o2sb8WAyVJWcecrvJfXEQWmc598d4gO32DilrUBsaNw=; b=0rZ2La8N7odLi/twTxZjPaPo3oY7e/vKOGr3C+sRl//4PX+NyfH3YqslAooWcCc5k6 89Ri711zLfbMh9IxOcnlW5bwFvzjQM+Xt1kWEsEuQd4bgI1O28LRpZWbiER2gysESXTR vq6Fv5wc4nPkEksbQ/ZKiA5SQtTrvuJmC9ApvzN4H6O34O/j9+xwNk3kiKMCE2w0n/ST 7NDVxzB4e/8wmWsLcp7kfLkSoI5YEIDkQbF4k8O2CNjUPsvNim/ovjYP/dPUw9wF32/o sRnAQQn6y6/N718tNGzJNYuAoDGWP2ikHME7tMof4KSA6vivPMqFH26UBapfD7UGPKHL g8aw== Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 Received: by 10.60.21.167 with SMTP id w7mr24500799oee.18.1357087559546; Tue, 01 Jan 2013 16:45:59 -0800 (PST) Received: by 10.76.20.243 with HTTP; Tue, 1 Jan 2013 16:45:59 -0800 (PST) In-Reply-To: <87bod85yxp.fsf@ist.utl.pt> References: <87a9svahv4.fsf@ist.utl.pt> <3C8C81DA-7057-4076-AA80-D1154BF86306@stellar.eclipse.co.uk> <87bod85yxp.fsf@ist.utl.pt> Date: Tue, 1 Jan 2013 19:45:59 -0500 Message-ID: Subject: Re: [gentoo-user] Re: [OT] codec for video embedded in presentation From: Michael Mol To: gentoo-user@lists.gentoo.org Content-Type: text/plain; charset=UTF-8 X-Archives-Salt: 88757320-bf4d-4c9b-9393-76a6262e6cdc X-Archives-Hash: fdb52d8ad89acfc75f8117210cd36c7d On Tue, Jan 1, 2013 at 5:19 PM, Nuno J. Silva wrote: > On 2013-01-01, Stroller wrote: > >> On 30 December 2012, at 11:39, Nuno J. Silva wrote: >>> ... >>> The AVI container has been used by windows for a long time, so I'd say >>> chances are that it will work on more systems, but I can't say for sure. >> >> But h264 in an AVI is invalid. >> >> AVI is dated and just plain nasty. >> >> You should use something else (like h264 in an MP4) if you possibly can. > > AVI is old, AVI has issues. AVI is not compatible with some > codecs. *But* AVI has been around for long enough to be supported by > many versions of Windows and Office, and what we're looking for here is > whatever offers the broadest support. I don't even think Windows (at > least up to 7) has a builtin h264 decoder. At least I remember having to > install codecs in Vista and 7 machines in order to view h264 Youtube > videos. Did a bit of googling. Windows 7 includes h264 support. In any case, there's something *critically* important missing in most of this discussion about AVI vs something else. Just because Windows supports AVI doesn't mean that Windows includes all possible codecs you might stuff in an AVI. There's h264, there's MPEG, MPEG2, Theora, RLE Windows Media and hundreds of codecs I've forgotten. And that's just video. For audio, there's more variation than there is for WAV[1]. In addition to anything WAVE files might contain, you might find just about anything. There's FLAC, AAC, Speex, MP2a, MP3, Vorbis and thousands more. AVI is just a container. Nothing more. Containers are like ZIP files or tar files, but instead of containing a filesystem, they contain a variable number of audio and video streams in such a way that the audio and video data for a moment in time are close together and easily accessible. The meat is in the audio and video streams, the format of which we call codecs. The big question is what *codecs* are available on the target systems. If you're looking for the absolute widest degree of support, you're looking at DIB encoding for video with uLaw PCM for audio. But that's going to be a *huge* file, because there's no compression at all! The best compression that's going to be available on the widest variety of systems is probably going to be MPEG2 video with MPEG2 layer 3 audio. The best compression that might be available, period, would be h.264, combined with MP4 audio, in an MP4 container. Almost as good results can be had with h.264 video, MP4 audio in an AVI container.[2] So, Francisco, what version of Windows will your slideshow be played on? [1] Yeah, WAVE files aren't exactly simple, either. They can contain different PCM encodings. There's aLaw, uLaw, float... [2] For full effectiveness, h.264 requires features that the AVI container doesn't have. -- :wq