Hi Daniel, thanks for your reply and help! On 09/24/2014 12:13 PM, Daniel Mack wrote: > On 09/24/2014 09:30 AM, Dario Ernst wrote: > Please test this with aplay, and make sure you're using a file that is > in stored in one of the sample rates and bit depths the hardware > supports natively. This is to rule out possible resampler problems. Okay, so i have taken myself a sample mp3 file that i know to glitch often and very audible, since its very "background~ish". I've converted this with: ffmpeg -i foo.mp3 -acodec pcm_s24le -ar 48000 test.wav I have tried PCM S24LE first, but have gotten: Playing WAVE 'test.wav' : Signed 24 bit Little Endian in 3bytes, Rate 48000 Hz, Stereo aplay: set_params:1233: Sample format non available Available formats: - S16_LE Even though the datasheet states that 24LE should be supported. Oh well, on to 16LE with 48kHz rate, which *should* be native. I still get the glitches. I have also tried other sample rates that should be supported, such as 41kHz, 44.8kHz, 96kHz and 192kHz (which isn't supported by the receiver, but by the DAC. Oh well, desperation makes you try anyways :D). None of them succeeded in Glitch-Free output. I usually use Alsa-Softvol, which i have also deactivated (simply mv'ed /etc/asound.conf /etc/asound.conf.off). > If that doesn't help, another debugging tip is to generate a wave file > that contains a simple 16-bit up-counter as audio payload. Play this, > and see whether you see a sane pattern with usbmon. If you can, tracing > the data on I2S is also a useful way that would show you whether the USB > stack in your device does the right thing. Okay, the first step here is to actually generate that test-file. I have yet to find a tool that allows me to discretely append tones of all frequencies to a wave file of given format and sample-rate. "Siggen" comes rather close, but i'm still at little at a loss on how to do "the right thing". On to the USB debugging. What exactly would a "sane pattern" look like? What am i looking for in terms of "errors" or problems, anyways? Also, i do fear that i cannot trace the I²S-Stream between receiver and DAC, as i don't have the necessary equipment for that. While i do have access to a digital scope at a neighbors' workshop, from what i understood from the "introductory" specification of that serial protocol, without an data logger // protocol analyzer that wouldn't be of too much help, right? Thanks for your help nonetheless. Sorry for my "beginnerism" on the topic. Best Regards -Dario Ernst ------------------------------------------------------------------------------ Meet PCI DSS 3.0 Compliance Requirements with EventLog Analyzer Achieve PCI DSS 3.0 Compliant Status with Out-of-the-box PCI DSS Reports Are you Audit-Ready for PCI DSS 3.0 Compliance? Download White paper Comply to PCI DSS 3.0 Requirement 10 and 11.5 with EventLog Analyzer http://pubads.g.doubleclick.net/gampad/clk?id=154622311&iu=/4140/ostg.clktrk _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
