wats the difference between mpg and mp4?

From wikipedia:

Audio Video Interleave, known by its acronym AVI, is a multimedia container format introduced by Microsoft in November 1992 as part of its Video for Windows technology. AVI files can contain both audio and video data in a standard container that allows synchronous audio-with-video playback. Like DVDs, AVI files support multiple streaming audio and video, although these features are seldom used. Most AVI files also use the file format extensions developed by the Matrox OpenDML group in February 1996. These files are supported by Microsoft, and are unofficially called "AVI 2.0".
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The Moving Picture Experts Group, commonly referred to as simply MPEG (.mpeg, .mpg, .mpe), is a working group of ISO/IEC charged with the development of video and audio encoding standards. Its first meeting was in May of 1988 in Ottawa, Canada. As of late 2005, MPEG has grown to include approximately 350 members per meeting from various industries, universities, and research institutions. MPEG's official designation is ISO/IEC JTC1/SC29 WG11.
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MPEG-4 Part 14, formally ISO/IEC 14496-14:2003, is a multimedia container format standard specified as a part of MPEG-4. It is most commonly used to store digital audio and digital video streams, especially those defined by MPEG, but can also be used to store other data such as subtitles and still images. Like most modern container formats, MPEG-4 Part 14 allows streaming over the Internet. The official filename extension for MPEG-4 Part 14 files is .mp4, thus the container format is often referred to simply as MP4. Devices that play .mp4 files are referred to as MP4 players.

Click here for information; MPEG video files which are not MP4 will not work on an iPod touch.

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Mpeg1/2/4 are different video encoding decoding formats.

.mp4 is the container format. A container format allows you to combine different multimedia streams (most of the time audio and video) into one single file. .avi is another well know container.

iPod Touch uses the .mp4 container and a a subset of Mpeg-4 called H264 / AVC (Advanced Video Coding). The audio format used by Touch is AAC.

Thanks for this.

VisualHub can format for iTouch from list of device selections but the H264 encoding is an option.

Should I always encode in H264?

NO reason not to.

But it takes longer....!

Anyway, I will give it a try.

Thanks a lot!

As I said...all my videos work 🙂

H264 does take longer to encode, but it's the most advanced format yet, very little digital artifacts. If you have the time, try the 2-pass option, the results are always stunning, you can see the variable bitrate working so nicely.

Thanks a lot 🙂

You are obviously the expert in video on this forum:) Great to have you here!

One last question: does it matter what the file suffix is? Visual hub (even with H.264 encoding) puts mp4 on the end whereas iTunes movies come with an m4v suffix.

Visualhub files always crash my iPod.
Regardless of the settings I use-mpeg4 or h.264 encoding.
Something is wrong with the specification of mpeg4 that visualhub is using.

Elgato's Turbo H.264 and mpeg streamclip files work fine with the presets.

I think the easiest way to think of it is:

.mpg - mpeg-1 and mpeg-2 are both different codec (how to compress video) and container formats (how to save video, audio and data together in a e.g filer format). Mpeg-2 is used in digital standard TV broadcasting and also on DVDs.

.mp4 - mp4 is a container format NOT a codec. The mpeg-4 standard contains different substandards and one is "mpeg-4 part 2" which is the "first" more simple codec used in .mp4 containers.

The other codec often used in .mp4 container is "mpeg-4 part 10" standard often called AVC (Advanced Video Codec) or h.264 depending which standard organisation one is refereing to.

AVC/h.264 codec is a very good one but it requires more CPU power to decode than mpeg-4 part 2 codec. This codec is also used for broadcasting high definition TV.

Hope this will help! 🙂

/valsjo