PCTV USB2 PAL / adds loud hum to correct audio
Quoted 2 lines · Andy Walls
I find audio at 8 ksps very unusual for a TV capture device.
I tried it with pulseaudio at 44100 samples/sec and with some commercial tuned in...
(no big copyright problem hopefully) :-)
i used this command:
parec --device=alsa_input.hw_1 > blah.raw resulting raw data: http://www.wgboome.de./blah.raw
Quoted 3 lines
The data set contains no large positive values
(nothing in the range 0x1000-0x7fff).
Now the noise is in the positive range, 2... I made a new filter program (see appendix), that produces acceptable but still distorted sound. filter output: http://www.wgboome.de./blah.ogg
Quoted 4 lines
The valuex
0x10and0x80do remind me of the YUV values for black: Y =0x10, U =0x80, V =0x80. Maybe some video data is getting thrown in with the audio?
sounds good...
because: the unwanted data changed its range now...
-arne
appendix:
...
(buf[i]/256>=0x80 && buf[i]/256<0xC0) ||
(buf[i]/256>=0x40 && buf[i]/256<0x80)) {...