Re: [SlimDevices: Audiophiles] Touch: Upsampling with sox?

2011-08-07 Thread kef2m

Hello, this is my first post, so please be kind.

In order to upsample Wav files to 48000 Hz PCM, the following file was
patched:
/Library/PreferencePanes/Squeezebox.prefPane/Contents/server/Slim/Player/Squeezebox.pm
This is on a Mac, but I assume finding this file on Windows should not
be too difficult.

The patch consists of adding two lines of code:
- one line to increase the bit depth from 16 to 24 bit
- the second to change/force the output rate to 48000 Hz

Here is the changed code:

sub stream_s {
# snip
if ($format eq 'pcm') { # unfortunately required for .wav files
# snip
if ( $track ) {
$pcmsamplesize = $client-pcm_sample_sizes($track);
$pcmsamplerate = $client-pcm_sample_rates($track);
$pcmchannels   = $track-channels() || '2';
}

# Add two lines of code
$pcmsamplesize   = 2;   # 1;1-16 bits, 2-24 bits, patch
$pcmsamplerate   = 4;   # 3;3-44100, 4-48000 10-88200, 
9-96000,
patch
# Upsample patch completed


The entry in the convert.conf file is:
wav pcm * *
# F
[sox_14_2] -q --buffer 32768  -t wav -r44100 -2 -c2 $FILE$ -t raw -C0
-3 -c2 -r48000 - polyphase -cutoff 1.0

Do add the line # F, for else no filename is passed to Sox, so nothing
can be upsampled.

Note:
Sox Version 14.2 is used to upsample, as this has the polyphase
option.
To use this, copy the version 14.2 Sox.exe file to:
/Library/PreferencePanes/Squeezebox.prefPane/Contents/server/Bin/darwin/
To distinguish this file from the distributed Sox.exe, the file is
renamed to sox_14_2.

I hope this does not look too complicated, and that it is of interest
for some people.


-- 
kef2m

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Re: [SlimDevices: Audiophiles] Touch: Upsampling with sox?

2011-08-07 Thread kef2m

I understand your comment.
The reason to upsample to 48kHz is that for me, the Meridian 568.1
better upsamples 48kHz material than 44.1kHz material. The 568.1 and
the digital speakers (DSP33) are 96kHz/24 bit capable. I have not done
any serious listening to upsample straight to 96kHz in Sox.
Just my opinion.


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Re: [SlimDevices: Audiophiles] Touch: Upsampling with sox?

2011-08-07 Thread kef2m

The music from the digital radio sounds 'warmer' than the cd's played
back from the budget cd-player connected to the Meridian 568.1. Also,
for 48 kHz material, the HS Out setting on the 568.1 makes an audible
difference. For 44.1 kHz material I am unable to hear such a
difference. This is my main reason to want to go to 48 kHz.
I do not have a link, this is my personal opinion.


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kef2m

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