DSD decoding with SoX resampling is turned off

[Igorf11]

Hello everybody!  I noticed an incomprehensible thing.  DSD64 and DSD128 are played back without decoding, while DSD256 and DSD512 are decoded into a 2-bit stream at a speed reduced by an order of magnitude, and at the output is converted back to the original format at a high speed.  Am I seeing something wrong or is down / up sampling really happening? SoX resampling is turned off.

[Tim Curtis]

No resampling but prolly the lack of metadata in the .DFF format. 

Zp up the dsd256 .DFF file and PM me a download link.

[Igorf11]

I have this information displayed on all DSD256 tracks. For example, on a file freely posted on the Internet: http://www.lindberg.no/hires/test/2L-125...04.dsf.zip

[TheOldPresbyope]

[on a late lunch break, honest]

Is it possible that the audio chain is working fine and we're just seeing a problem with parsing the parameters to display them? With my Khadas Tone Board I see

1. for a DSD64 test file from 2L.no

Code:

pi@moodeLR:~ $ cat /proc/asound/card2/pcm0p/sub0/hw_params
access: RW_INTERLEAVED
format: DSD_U32_BE
subformat: STD
channels: 2
rate: 88200 (88200/1)
period_size: 11025
buffer_size: 44100

which looks ok.

For this track the Audioinfo popup reports:

Code:

INPUT / OUTPUT
Source USB/MUSIC/2L-DSD/2L-45_stereo_01_DSF_2822k_1b.dsf
Encoded at DSD64, 1 bit, 2.822 MHz Stereo
Decoded to DSD bitstream, 5.645 Mbps
Destination Local
Output rate DSD bitstream, 5.645 Mbps

which also looks ok.

2. for a DSD256 version of the same track

Code:

pi@moodeLR:~ $ cat /proc/asound/card2/pcm0p/sub0/hw_params
access: RW_INTERLEAVED
format: DSD_U32_BE
subformat: STD
channels: 2
rate: 352800 (352800/1)
period_size: 32768
buffer_size: 131072

which again looks ok.

But for this track the Audioinfo popup reports

Code:

INPUT / OUTPUT
Source USB/MUSIC/2L-DSD/2L-45_stereo_01_DSF_11289k_1b.dsf
Encoded at DSD 11.288 MHz
Decoded to 2 bit, , 2.257 Mbps
Destination Local
Output rate DSD bitstream, 22.579 Mbps

Compare the "Encoded at" and "Decode to" lines to the previous case. Sorry, I don't time to find where the parsing is done.

Regards,
Kent

[TheOldPresbyope]

Maybe this?

Code:

pi@moodeLR:~ $ mediainfo /media/MUSIC/2L-DSD/2L-45_stereo_01_DSF_2822k_1b.dsf
General
Complete name                            : /media/MUSIC/2L-DSD/2L-45_stereo_01_DSF_2822k_1b.dsf
Format                                   : DSF
Format/Info                              : Direct Stream Digital Stream File
Format version                           : Version 1
File size                                : 207 MiB
Duration                                 : 5 min 7 s
Overall bit rate                         : 5 647 kb/s
...
Audio
Format                                   : DSD
Format/Info                              : Direct Stream Digital
Commercial name                          : DSD64
Format settings                          : Little
Duration                                 : 5 min 7 s
Bit rate                                 : 5 645 kb/s
Channel(s)                               : 2 channels
Channel layout                           : L R
Sampling rate                            : 2 822 kHz
Compression mode                         : Lossless
Stream size                              : 207 MiB (100%)

vs

Code:

pi@moodeLR:~ $ mediainfo /media/MUSIC/2L-DSD/2L-45_stereo_01_DSF_11289k_1b.dsf
General
Complete name                            : /media/MUSIC/2L-DSD/2L-45_stereo_01_DSF_11289k_1b.dsf
Format                                   : DSF
Format/Info                              : Direct Stream Digital Stream File
Format version                           : Version 1
File size                                : 827 MiB
Duration                                 : 5 min 7 s
Overall bit rate                         : 22.6 Mb/s
...
Audio
Format                                   : DSD
Format/Info                              : Direct Stream Digital
Commercial name                          : DSD256
Format settings                          : Little
Duration                                 : 5 min 7 s
Bit rate                                 : 22.6 Mb/s
Channel(s)                               : 2 channels
Channel layout                           : L R
Sampling rate                            : 11.3 MHz
Compression mode                         : Lossless
Stream size                              : 827 MiB (100%)

Note the difference in the way mediainfo formatted the bit rate and sampling rate for the two.

Regards,
Kent

[Tim Curtis]

I also thought it might be a parsing issue with the media info output but it turns out to a bug in the formatRate() function in playerlib. The elements for dsd256 and higher were missing from the array :-0

All fixed now :-)

[Igorf11]

Many thanks for your help! ))

[Igorf11]

Good day!  It looks like the same nonsense with pcm format 768 kHz ...

[Tim Curtis]

PM me a download link to the file and I'll have a look.

[Tim Curtis]

Looks like mediainfo reports a blank encoded_at rate for this file.

Since that may occur for other files I added a fallback to get the encoded_at rate from MPD database.

The fix will be in the next release.