Hello
I’m new on this list. I’m working on a radio orienteering project for a
university course and we are using gnuradio for signal analysis.
I’m trying to get the Edirol UA-25 (USB sound card) to work with
gnuradio. My test program currently looks like this:
—snip—
UA-25 as audio source
src0 = audio.source (96000, “hw:1,0”);
laptop on-board sound card as destination
dst = audio.sink (44100, “hw:0,0”)
connect them
fg.connect ((src0, 0), (dst, 0))
—snap—
This works just fine when using 16-bit and a sampling rate of 44.1kHz on
the UA-25, but I will need 24 bits (with 96kHz). Those settings produce
the following error however (verbose output):
—snip—
PCM name: hw:1,0
Access types:
MMAP_INTERLEAVED YES
MMAP_NONINTERLEAVED NO
MMAP_COMPLEX NO
RW_INTERLEAVED YES
RW_NONINTERLEAVED NO
Formats:
S24_3LE YES
Number of channels
min channels: 2
max channels: 2
2 channels YES
Sample Rates:
min rate: 96000 (dir = 0)
max rate: 96000 (dir = 0)
8000 NO
16000 NO
22050 NO
32000 NO
44100 NO
48000 NO
96000 YES
192000 NO
audio_alsa_source[hw:1,0]: failed to find acceptable format
Traceback (most recent call last):
File “./ardf.py”, line 37, in ?
fg = build_graph ()
File “./ardf.py”, line 19, in build_graph
src0 = audio.source (96000, “hw:1,0”);
File “/usr/local/lib/python2.4/site-packages/gnuradio/audio_alsa.py”,
line 219, in source
return _audio_alsa.source(*args)
RuntimeError: audio_alsa_source
—snap—
I tried understanding what the problem was, but wasn’t able to figure it
out. audio_source_alsa seems to not be able to set the sample format
(S24_3LE?) and it seems that audio_source_alsa.cc specifies only S16 and
S32 as acceptable sample formats.
I’m guessing that audio_source_alsa supports 24-bit samples, so does
anybody have an idea what I’m doing wrong?
I should mention that I’m running the latest gnuradio development code
from subversion (updated last night) on Debian Sid.
Best regards,
Matt