Can sound quality be affected by player software?

Quince

I've read claims that different sound players such as WMP, Winamp, VLC, etc., can produce different sound quality. I fail to see how that can be as long as no DSP plugins are being used. I thought player software simply sends the digital stream to the soundcard which is buffered before sending out over S/PDIF etc. so that jitter is not an issue. How can there possibly be a difference if there's no processing done to the stream?

Mata Hari

This all depends on what format you are playing. When playing lossless formats (wav/flac/ape/cd audio) it should not matter what player you use (and it doesn't). However, if you play lossy formats, like mp3, where the main stories of quality differences come from, it does matter. This has all got to do with the decoder used and how far it stretches the specifications of the codec. However, in most recent players, there is not that much of a difference anymore between decoders. they all should sound very acceptable with mostly only very small psychoacoustic differences. In 'thy olden days', there was however much quality difference in players like winam and wmp, or even between versions of 1 player (winamp was quite bad in that respect in the 1 and low 2 versions)

Quince

I thought that nowaday decoders are usually separate from the players, usually implemented as DirectShow filters and similar. Especially in video codecs, I notice in many cases different players using the same decoder for playback.

Mata Hari

This is only the case with players using the Direct Show interfaces. Winamp for instance uses its own mp3 decoder (in_mpeg iirc), and so does VLC and foobar.