2013/1/1 Michael Mol <mike...@gmail.com> > On Tue, Jan 1, 2013 at 5:19 PM, Nuno J. Silva <nunojsi...@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
