Hello ALSA users, I'm working on an audio archiving project for a non-profit radio station. For this I have setup an Ubuntu 8.10 system using the provided ALSA 1.0.17. We would like to record an AES/EBU stream connected to the digital input of an EMU 0404 PCI card. I have figured out how to record the digital stream, but the audio stream consists of valid audio samples interleaved with 0 samples. This results in a stream which plays back at half speed with some other regular clicking artifacts (assuming that is because the timing is different). Example stereo audio stream (Left, Right, 0, 0, Left, Right, 0, 0, ...): 0x12341234 0x12341234 0x00000000 0x00000000 0x56785678 0x56785678 0x00000000 0x00000000 0x9ABC9ABC 0x9ABC9ABC 0x00000000 0x00000000 ... Audio was captured with the following arecord commands: # Native capture (8 channels of 48KHz 32 bit) arecord -D hw:0,2 -f S32_LE -c 8 -r 48000 test.wav # Using plughw to capture a 24 bit stereo stream arecord -D plughw:0,2 -f S24_LE -c 2 -r 48000 test.wav In both cases the previously described problem is observed. Documentation on using this device in Linux seems rather sparse, but from various blogs and emails on the Internet I discovered: There are 3 capture devices. 1st is for analog capture, 2nd is for Mic capture and 3rd is for Multichannel capture (the one which we want and will allow recording from the digital input). I set the 'Clock Internal Rate' mixer setting using amixer to "SPDIF" to sync to external AES/EBU clock. I routed DSP 0 and DSP 1 capture sources to "0202 SPDIF Left" and "0202 SPDIF Right" respectively. I suspect this is a bug in the driver. Has anyone had success with this card and recording AES/EBU from the digital input? Any ideas what is wrong? Thanks in advance! Best regards, Josh Green ------------------------------------------------------------------------------ SF.Net email is Sponsored by MIX09, March 18-20, 2009 in Las Vegas, Nevada. The future of the web can't happen without you. Join us at MIX09 to help pave the way to the Next Web now. Learn more and register at http://ad.doubleclick.net/clk;208669438;13503038;i?http://2009.visitmix.com/ _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
