I'm writing this from a Windows XP machine. In investigating why my recent low bitrate MPEG-1 VBR streams were not playing on Windows Media Player, I have discovered that WiMP does not like MPEG-1 files with more than 3 consecutive B-frames. As MegaPEG currently has a GOP pattern preset for 15/5 (IBBBBPBBBBPBBBBI), if you plan to make internet streams, I suggest avoiding this particular GOP pattern. For my part, I've re-encoded the newest streams on www.lobecandy.com (See: Lone Star Girl) and I need to re-do the Sugartooth MegaPEG.X sample (UPDATE: completed, now slightly lower bitrate with same quality).

Currently, the state of the union for MPEG-1 playback is as follows:

1. QuickTime. Excellent support for MPEG-1 VBR, from low-bitrate web streams up to HD frame sizes. Downside: no support for MP3 (MPEG-1 layer 3) audio in an MPEG-1 System Stream. Also, with low-bitrate MPEG-1 Layer II audio, QuickTime seems to be blowing a mighty hot signal out the audio port, almost like their Layer II decoder is emitting a dc-like signal on the low end. Tends to distort slightly on PowerBooks and low-fi playback devices in general.

2. Windows Media Player. Excellent support for MPEG-1 VBR, as long as the GOP limitation (above) is observed. To my eye, the IDCT accuracy of Windows Media is not as good as QuickTime. Also, the difference in display gamma makes low-light blocking artifacts more visible.

3. VideoLAN (Windows, Mac OS X). Excellent support for MPEG-1 VBR. However, some rocket scientist on the VideoLAN project decided that the way to keep streams synchronized is to pitch bend the audio (time expand/compression anyone?). If you ask me, it sounds like hell. Unless, of course, one longs for the days of the analog audio tracks that were optically printed on the edge of Super8 and Super16 mm film. Wow and flutter, anyone? Bueller? Anyone?