Technical Q&As

SND 06 - Sound Track Hiccups under Windows 95 (27-September 96)

Q A new client of mine has problems with Sound-track-only QuickTime for Windows playback under Windows 95. During Movie Player and/or Director playback from CD-ROM, the audio breaks up or hiccups regularly. On Windows 3.1, (as well as on the Mac) the same files play with no problems. Also, other QuickTime movies containing video tracks play back their audio just fine under Win95, Win3.1 and MacOS. Is it possible that the interleave ratio is a source of the problem?

A There is only an interleave if the movie contains multiple tracks. If this is a one-sound-track movie, then there is no interleave. I believe your client's problem is a case of the data rate being too low for the CD-ROM cache/buffer size. The CD-ROM drive goes to sleep between physical accesses and can't wake up in time to provide the next data to QTW without an audio dropout.

In the System Control Panel, select Performance|File system|CD-ROM. Set the "Supplemental cache size" slider to "Small" and the "Optimize access pattern for:" value to "No read-ahead". Then click "Okay", "Close", and "Yes" to restart the computer.

As an alternative, you can increase the data rate by increasing the quality of the sound.

Technical Q&As

Previous Question | Contents | Next Question