On 12/19/16, Adam Puckett <[email protected]> wrote: > On 12/19/16, Nicolas George <[email protected]> wrote: >> L'octidi 28 frimaire, an CCXXV, Adam Puckett a écrit : >>> When you say it "works" for you (I have to double the ^ to escape on >>> Windows), >> >> My condoleances. >> >>> does it produce this file? >> >> Yes, approximatively. Are you just hearing Vorbis artifacts? > No, because when I ffplay the same command, or generate uncompressed > files, I hear the same thing. I've checked the math and nothing > appears to be wrong according to the documentation, because when t = > 10, 10/10 = 1, 262*2^1 = 520, so the formula should produce a 520 Hz > sine at the end, but the resulting frequency at the end is close to 1 > kHz. This is puzzling.
The formula is wrong. Consider sin(262*2^(t/10)*2*PI*t). phase, ph(t) = 262 * 2^(t/10) * 2 * PI * t angular freq (in radians/s), w(t) = dph(t)/dt = 262 * 2 * PI * (2^(t/10) + log(2)/10 * 2^(t/10) * t) freq(t) = 262 * (2^(t/10) + log(2)/10 * 2^(t/10) * t) so, at t = 10, freq(10) = 262 * (2 + log(2) * 2) = 887 Hz Thx _______________________________________________ ffmpeg-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email [email protected] with subject "unsubscribe".
