With varying degrees of success, most models (apart from those listed as 'NA' in the comparison table) tested can play music and video and show photos.
Digital video and audio is compressed using different codecs (short for coder-decoder). Most codecs, such as the MP3 audio format, are designed to create a file size that is as small as possible while keeping most of the inherent audio or video quality intact.
Unfortunately, different companies have different priorities on what they want in a media file, which means media players are now coping with several different audio and video formats.
Difficulties playing video
Most of the models tested have difficulties playing certain video formats, with some models even unable to play a file they claim to support. The problem is that even though a file may appear to have the correct file type, as indicated by its name (*.mov, *.mp4, *.mp3 and so on), the actual codec used to create it may be different from the common standard.
Playing movies can be even more problematic than audio, as a movie file contains video and audio content, with both bundled together into a single file. This type of file is called a “container”, generally shown with a name ending in *.avi, *.mov, *.wmv or similar.
However, just to confuse things, containers can often support a variety of codecs; for example, it’s possible to have an *.avi file that contains video compressed with MPEG or XVID and audio as a *.wav file. Therefore, while some media players may say they support a wide variety of video file formats, they may not cope with the different types of files contained within a video file format.
If you find a file won’t play on your application or media player, you may be able to convert the file to a suitable format using a free transcoding program such as Mediacoder.