I am totally annoyed by this. I have been using the Zen Vision:M for 2-3 months now, and I have been asked this question like a zillion times.
Is that a mp4 player?
Arrrrrgh! For goodness sake, mp4 player? I do agree that a lot of ‘non-brands’ have been marketing their media players as mp4 players, but there is no such thing as an mp4 audio or video.
mp3, or MPEG-1 Layer3 is a audio compression standard. It’s defines the algorithm (how to) to compress the audio file. Now generally a file format and an audio compression standard are seperate things. However, for mp3, both are defined under the same umbrella. So its a mp3 compressed file, in a mp3 file format.
mp4 or MPEG-4 Layer 14 is file format. More specifically a container format. This can support a multitude of compression techniques for audio and video streams. So basically, you can have a mp4 file which contains an h.264 compressed video, or even a mp3 compressed audio.
Now, for portable media players, the important thing is not which file format it can support. Most support almost all formats, and more can be added by simple firmware upadtes. What matters is the compression algorithms, or codecs that they support. Generally, codecs require some kind of hardware accleration, and thus is not a simple add-on.
So please don’t ask me if the Vision:M is a mp4 player!! It’s a media player. :D