3 ms·
It means the Red Book CD audio 'frame' was 1/75 of a second. I don't know what Director did.
by alexdbird 3y ago
It means the Red Book CD audio 'frame' was 1/75 of a second. I don't know what Director did.
- helpfulContrib 3y agoRight - is it not the case that this object is tracking Mode 1 CD-ROM physical (i.e. rotational) frames, not audio/video frames? That is .. a Mode 1× CD-ROM drive reads 150/2 = 75 consecutive sectors per second ... 150k/sec transfer rate ..
- pavlov 3y agoThat makes sense, I never knew that. Thanks! Now I wonder where the Audio CD 44.1k sample rate came from. 44,100 divided by 75 is 588 samples per channel. That doesn't seem like a particularly useful number, whereas 48k / 75 is a more appealing 640.
- sp332 3y agoThe audio format was copied from an earlier standard developed for storing sound on video tape. https://stason.org/TULARC/pc/cd-recordable/2-35-Why-44-1KHz-Why-not-48KHz.html https://stason.org/TULARC/pc/cd-recordable/2-35-Why-44-1KHz-...
- kaetemi 3y agoAdd error correction overhead to that weird number.
- pjz 3y agoMy understanding is that 44.1k is to improve error correction. 44100 == 2^2 * 3^2 * 5^2 * 7^2 ... something about vertices of a hypercube.