[FFmpeg-soc] BFI

Sisir Koppaka sisir.koppaka at gmail.com
Sat Mar 22 19:32:46 CET 2008


I have a question regarding the PCM frequency.
The PCM wiki page says :

frequency = 1000000 / (256 - frequency_divisor)

A common divisor is 211 which yields an integer frequency of 22222 Hz, a
common rate in the days of the Sound Blaster. Note that while very low
frequencies (all the way down to 3921 Hz) were supported, frequencies above
45454 Hz were not.Does this mean

Does this mean that I have to hardcode the frequency_divisor as 211? Right
now, I'm doing this:
sample_rate = 1000000/(256 - get_byte(pb))

where the get_byte() fetches the first byte of the PCM bytestream in the
file. I saw that this was done in one of the codecs, so I took it to mean
that the first byte contained the frequency_divisor. Maybe that inference is
wrong?

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Sisir Koppaka



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