[PROBLEM] White noise playing DSD audio

[Tim Curtis]

Thats an interesting result.

IIRC MPD and ALSA negiotiate the final format based on what the device reports it can support, whether plughw, hw or iec950 is used, etc. I think when SoX resampling is off that ALSA (Speex?) resampling is being used downstream of MPD which may not be as good as SoX. This would need to be confirmed.

[jcucurull]

The question in this case would be, at which sample rate is MPD converting the DSD signal to PCM? 192, 176, 96 or 88? Is not possible to define it in the configuration of MPD to avoid resampling again?

[jcucurull]

When Tim mentioned that maybe the automatic conversion was done by ALSA made me think that maybe it was not a so bad idea to use SoX because ALSA will have a worse resampler. However, the issue was that no multichannel was supported via the Moodeaudio configuration. Then, I have been checking directly in the MPD configuration file and I have seen that from there I can enable SoX resampling for both stereo and multichannel just using the "*" in this line:

audio_output_format "96000:32:*"

It is not that I like very much to upsample every song that I reproduce to 96/32, but at least works for stereo and multichannel audio and the quality of the resampling should be very high due to the use of SoX.

Thus, @Tim Curtis would it be possible to add the option "Any" in the channels section of the SoX graphical configuration screen of Moodeaudio?

[Tim Curtis]

When Tim mentioned that maybe the automatic conversion was done by ALSA made me think that maybe it was not a so bad idea to use SoX because ALSA will have a worse resampler. However, the issue was that no multichannel was supported via the Moodeaudio configuration. Then, I have been checking directly in the MPD configuration file and I have seen that from there I can enable SoX resampling for both stereo and multichannel just using the "*" in this line:

audio_output_format "96000:32:*"

It is not that I like very much to upsample every song that I reproduce to 96/32, but at least works for  stereo and multichannel audio and the quality of the resampling should be very high due to the use of SoX.

Thus, @Tim Curtis would it be possible to add the option "Any" in the channels section of the SoX graphical configuration screen of Moodeaudio?

Sure. I'll add to the TODO list for upcoming 9.0.4

[jcucurull]

Thanks Tim!

By the way, I have asked in the MPD forum if there is a manner to resample only in case some of the values set are exceeded. That would be good in cases such as mine, where the AVR supports all the sample rates up to a certain limit (in fact bluray players usually allow you to set a limit). Of course another option would be to update my 17th year old AVR, but it is more fun like this 

[Tim Curtis]

Thanks Tim!

By the way, I have asked in the MPD forum if there is a manner to resample only in case some of the values set are exceeded. That would be good in cases such as mine, where the AVR supports all the sample rates up to a certain limit (in fact bluray players usually allow you to set a limit). Of course another option would be to update my 17th year old AVR, but it is more fun like this 

lol

There is the selective resampling feature. You set a target rate and then choose one of the Selective Rasampling options.

   

Btw if you want to try the 'Any' option for channels just install the files in this commit
https://github.com/moode-player/moode/co...f7a249d853

[jcucurull]

I have seen these selective resampling options, but they seem to me that are thought to up sample from lower sample rates to higher. What I need is to downsample when a certain rate is exceeded.

Later at night or tomorrow morning I will try the files in the commit!

[MikeyFresh]

I have opened a discussion in MPD forum: https://github.com/MusicPlayerDaemon/MPD...sions/2066

Out of curiosity maybe you can re-rip some SACD MCH tracks using the DST decompression option. While the resulting file sizes will be larger, storage is relatively cheap these days, and this test would reveal whether or not this white noise you hear is an artifact of on-the-fly DST decompression.

Stereo 2-ch playback of .dsf at 96kHz is OK?

[jcucurull]

I have opened a discussion in MPD forum: https://github.com/MusicPlayerDaemon/MPD...sions/2066

Out of curiosity maybe you can re-rip some SACD MCH tracks using the DST decompression option. While the resulting file sizes will be larger, storage is relatively cheap these days, and this test would reveal whether or not this white noise you hear is an artifact of on-the-fly DST decompression.

Stereo 2-ch playback of .dsf at 96kHz is OK?

It is a bit strange it is due to the decompression, because the same file that does not work for me in my Moodeaudio + AVR, works for Tim in his. Also, the same file works for me in other platforms (bluray in the same AVR and computer with a Sound Blaster XFi HD USB).

[jcucurull]

Btw if you want to try the 'Any' option for channels just install the files in this commit
https://github.com/moode-player/moode/co...f7a249d853

Tested and working!