More > JRiver Media Center 30 for Mac
Streaming HD audio distorted [Solved]
blgentry:
In an absolute sense, yes changing sample rates, with conventional algorithms, is lossy. But it's not lossy like converting to MP3 or other lossy CODECs which reduce the information rate. Rather, it's lossy in a much less significant way. Yes, the waveforms are altered. It may or may not be audible. It should not be an obvious or glaring difference. It should be very subtle if it's audible at all. I would not be very concerned about it.
Brian.
dpfels:
As a post-script to this discussion, I see that 192KHz, streaming as 192KHz through my DAC Audio Path states that "No changes are being made."
All other sample rates are being upsampled to 192KHz, which is fine with me.
Dan
dpfels:
I am taking another stab at this thread - I have discovered some additional details and concerns.
First, I have moved to MC31 for Mac, so this may be in the wrong location, but I wanted to keep this thread and I don't see any changes from the newer version that fix this problem.
To recap, unless I force (by DSP) all sample rates to the set rate of my DAC (either 192 or 96), the audio is distorted. The solution was to set to 192 and up sample everything else.
However, today, I compared some 96KHz FLAC files played from MC (with DSP upsampling to 192KHz) or from another App (Amadeus Pro). The other App sends the audio at the native sampling rate (confirmed by looking at the sample playback rate in either Audio MIDI Setup or in my DACs control software (Focusrite Control).
The upsampled files from MC were clearly missing some details, which caused me to do some digging (I want to play all audio without DSP, if I can). First, it is clear that the output (with the DSP>output off - unchecked) is passing the correct sample rate. Audio MIDI Setup and Focusrite control all correctly switch to the correct sample rate on the fly, no matter which file is being played in MC. That said, some of the time, the audio is perfect. Other times, it is distorted and playing at the wrong speed (this was the original problem in this thread).
This causes me to suspect the following: I think that the distortion is coming from some sort of processing within MC, not with the sample or bit rate. I am not sure how to test this directly (beyond looking at Audio MIDI setup or Focusrite Control), but I can see that the sample rate is correct. Additionally, I can occasionally get perfect audio from MC at any sample rate (tested across about 5 files at a variety of sample rates, earlier today), but it doesn't last.
Any suggestions or ideas? Is there any other debugging I can do? Again, I can keep using this with the DSP, but it is altering the sound in a noticeable way, which I would like to avoid.
Thanks,
Dan
dpfels:
More data:
I can output at 192KHz (the max for my DAC) without any DSP settings (DSP bypassed/unchecked).
For any other sample rate, I need to match the number of channels on my DSP (this varies by sample rate; no single channel number setting works for all sample rates between 44.1 and 192KHz), or I need to upsample to 192KHz.
Additionally, if I test this without engaging the DSP (switching between files of different sample rates; FLAC 96 to 192 and back), MC31 crashes after playing a few tracks with the wrong settings. This crashing happens fairly consistently under these conditions.
I suspect that any DSP settings causes the output stream to pass along additional information to the DAC. More likely, forcing sample-rate conversion ensures that the number of channels are always the same. (However, I don't need to change the # of channels if I am converting the sample rate.). In any case, it is not solely a problem with the sample rate as I am currently pushing the audio stream with "no change" in the output sample rate.
Is there any way to give the native output from MC to recognize the required format for the stream going into Core Audio? It seems to do this adjusting for sample rate correctly (sample rate out of MC is recognized by Audio Midi Setup.
Otherwise, upsampling is the only stable DSP setting, but that comes at the cost of some audio quality.
Thanks for reading my long ramble!
Dan
PS - I am posting all of this thinking that it might be useful for someone else in the future, even though my particular DAC is a bit unusual.
bob:
I'm not sure I understand all that's going on here but if you are up-sampling, under the audio settings, make sure SoX is enabled.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version