On Mon, Feb 25, 2008 at 12:00:22PM +0000, Mathis Richter wrote: > 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?
The code doesn't support S24_3LE because when we wrote it, we didn't have any cards that used that format, and it wasn't obvious (to me) exactly how the format was represented. It would be great if you could sort this out and submit a patch with the fix. http://gnuradio.org/trac/wiki/PatchSubmissionGuidelines Let me know if you need more of a clue, and I'll take a look at the code. Thanks, Eric _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
