Re: [gentoo-user] Re: [OT] codec for video embedded in presentation

[Francisco Ares <frares@gmail.com>]

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2013/1/1 Michael Mol <mikemol@gmail.com>

> On Tue, Jan 1, 2013 at 5:19 PM, Nuno J. Silva <nunojsilva@ist.utl.pt>
> 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
>
>
Wow, what a class! Thank you a lot, that explained much of my doubts. I had
no problems with audio, I use several programs and several codecs for
messing around with different audio file formats. But video was still a
mystery to me.

As a matter of fact, I am not sure on what windows version this
presentation will be played, it is a training presentation, so I suppose we
can only expect at least XP.

I will bring a free MS office player, so that part should not be a problem.
And also a "K-Lite" or any other codecs package installer.

Thanks
-- 
Francisco
"If you have an apple and I have an apple and we exchange apples then you
and I will still each have one apple. But if you have an idea and I have
one idea and we exchange these ideas, then each of us will have two ideas."
- George Bernard Shaw

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