ADC Home > Reference Library > Technical Q&As > Legacy Documents > QuickTime >
Legacy Document
Important: This document is part of the Legacy section of the ADC Reference Library. This information should not be used for new development.
Current information on this Reference Library topic can be found here:
|
|
Q I am developing code which allows users to mix an additional
sound into the sound track of a QuickTime movie playing under Windows. Since this
cannot be accomplished when the CD- ROM is mastered -- the placement of the sound effect
must be controlled by the user -- I am extracting the sound samples from the QuickTime movie
and blending them with a WAV file which contains the sound effect.
While testing this technique using one of the sample movies from the QuickTime for Windows beta CD- ROM, I discovered that the SoundDescription record returned by GetMediaSample contained the constant 'sowt' in the dataFormat field. The only three formats documented in the QuickTime documentation are raw, MAC3, and MAC6. I need to know what the format of the 'sowt' samples is so I can mix them with the WAV samples. A You're reading the byte backwards. 'sowt' is actually 'twos', which means that the values of the samples go from a minimum point to a maximum point, unlike the raw format, which has a binary offset from zero. In all other aspects, 'twos' and 'raw' samples are the same.[May 01 1995] |