mpdPup - Simplified MPD Music Server/Jukebox - v0.9.3

For talk and support relating specifically to Puppy derivatives
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jrling
Posts: 47
Joined: Wed 27 Jun 2012, 13:51

#161 Post by jrling »

ldolse - I am happy to do some experimental on my system. Of course, we are getting into system-specific territory and the preferable solution no doubt for those with dual-core processors like me is to have MPD running on its own separate core - as suggested by Dynobot but requiring some utilities to be included in the build to achieve.

A couple of questions if I may -

1. Is there a config file that can be edited to change the default Nice setting of MPD at boot time?
2. If not, can you let me have the command line that will search for the MPD PID No, return the value and then apply that value to a 'renice PID xx -19' in the script file I am using to apply different Nice values to processes, as per my previous postings.

Many thanks

ldolse
Posts: 367
Joined: Fri 23 Oct 2009, 16:33

#162 Post by ldolse »

jrling wrote:1. Is there a config file that can be edited to change the default Nice setting of MPD at boot time?
No - not today. This is how I plan to implement the function though.
jrling wrote:2. If not, can you let me have the command line that will search for the MPD PID No, return the value and then apply that value to a 'renice PID xx -19' in the script file I am using to apply different Nice values to processes, as per my previous postings.
You could try something like this

Code: Select all

ps -ef | grep XYZ | grep -v grep |  awk '{ print $2 }'
- replace XYZ with the process name you want.

jrling
Posts: 47
Joined: Wed 27 Jun 2012, 13:51

#163 Post by jrling »

Thanks ldolse

I found this command to renice by name rather than PID No. -

renice XX -p $(pidof <name>)

and it seems to work!

multiblitz
Posts: 33
Joined: Sat 28 Jul 2012, 17:52

#164 Post by multiblitz »

Can you share with us some of your plans for the next version of mpdpup...the last one was already absultely stunning...I am looking forward to the next one very much....

ldolse
Posts: 367
Joined: Fri 23 Oct 2009, 16:33

#165 Post by ldolse »

multiblitz wrote:Can you share with us some of your plans for the next version of mpdpup...the last one was already absultely stunning...I am looking forward to the next one very much....
The next one will primarily just be about further refinement of the last one. It will still use the same kernel and base os as the last version. Jumping to a new kernel is going to be a big project and I'd like to get some of the current requests/problems resolved first.

Here are the things I've been thinking about:
  • final fix for unmute, nrpacks
  • 0.17 by default, remove 0.16 (my personal issue was finally isolated to a bad power supply)
  • Renicing/priority tweaks discussed over the last few pages, enable mmap
  • fix albumbler so that it can finally be used from remote control on bootup
  • update mpd, mpdlcd, hiface drivers
  • CIFS credential handling suggestion
  • add playlist/radio hotkey programming to empcd (this might be a stretch, I need to learn a bit more C to do this right)
  • Add libexiftool and start working on scripts to extract album artwork from metadata as well as automatically fixing filenames based on metadata

Jean-Louis P
Posts: 22
Joined: Sun 23 Sep 2012, 18:06

Evolutions

#166 Post by Jean-Louis P »

HI Idolse, Hi all

* suggested evolution (for the dumbs possibly :lol: )
- at boot, error message if ethernet unavailable
- at boot, error message if remote file server unavailable
- option to display the cover art on the device (eg I use a NetBoot as my server with Mpod remote control but would find it great to have a permanent display with a large size)
- use a rating for titles/album in the mpd database

* more general question : i use Mpod and Mpad on Apple devices but find these clients very limited, specifically the display of long titles or album names. What are good alternatives ?

I have not upgraded until now but already very happy !

Jean-Louis

Magellan
Posts: 17
Joined: Tue 06 Mar 2012, 09:53

Resampling

#167 Post by Magellan »

Hi!
I have been using MPD puppy for some time, and I am very happy for the labor that has been put into this software. Thank you.

I have a question. I don´t know but maybe the information about this are to be find in the forum somewhere, but there is a lot of posts to read through.
Anyway. My question is simple. If I play a - say 24 bit 96 kHz file. Do MPD pup any resampling to 16 bit 44,1? Or is the file sent to the DAC in it´s original bit and samplerate? I am asking, because when running my DAC under Windows it only accepts maximum 16 bits and 48 kHz. Running under MPD puppy there is no problem playing 24 bits 96 kHz, but is this due to resampling taking place?

Best Regards

ldolse
Posts: 367
Joined: Fri 23 Oct 2009, 16:33

Re: Resampling

#168 Post by ldolse »

@ Jean-louis - I'll try to implement some of those suggestions - some straightforward, others are easier said than done.

Regarding MPoD/MPaD, I'm not aware of any good alternatives for iOS. Best option might be to try some of the PHP clients in the iOS Safari browser.

Magellan wrote:I have a question. I don´t know but maybe the information about this are to be find in the forum somewhere, but there is a lot of posts to read through.
Anyway. My question is simple. If I play a - say 24 bit 96 kHz file. Do MPD pup any resampling to 16 bit 44,1? Or is the file sent to the DAC in it´s original bit and samplerate? I am asking, because when running my DAC under Windows it only accepts maximum 16 bits and 48 kHz. Running under MPD puppy there is no problem playing 24 bits 96 kHz, but is this due to resampling taking place?
Hi, glad to hear it's been working for you. The behavior depends on your Sound device/DAC. When it's initialized it tells ALSA what bitrates it supports. If you play a bitrate that the DAC doesn't support then it will be resampled to a bitrate that your DAC does support. This behavior can be disabled, but if you do that it means you won't be able to play back content at bitrates your DAC doesn't support.
Last edited by ldolse on Thu 31 Jan 2013, 11:56, edited 1 time in total.

Magellan
Posts: 17
Joined: Tue 06 Mar 2012, 09:53

Re: Resampling

#169 Post by Magellan »

ldolse wrote:
Magellan wrote:I have a question. I don´t know but maybe the information about this are to be find in the forum somewhere, but there is a lot of posts to read through.
Anyway. My question is simple. If I play a - say 24 bit 96 kHz file. Do MPD pup any resampling to 16 bit 44,1? Or is the file sent to the DAC in it´s original bit and samplerate? I am asking, because when running my DAC under Windows it only accepts maximum 16 bits and 48 kHz. Running under MPD puppy there is no problem playing 24 bits 96 kHz, but is this due to resampling taking place?

Best Regards
Hi, glad to hear it's been working for you. The behavior depends on your Sound device/DAC. When it's initialized it tells ALSA what bitrates it supports. If you play a bitrate that the DAC doesn't support then it will be resampled to a bitrate that your DAC does support. This behavior can be disabled, but if you do that it means you won't be able to play back content at bitrates your DAC doesn't support.
My USB DAC also accepts SPDIF. I know it accepts 24 bit 192 kHz over SPDIF. I am not sure however, if it also accepts the same bit- and samplerate over USB. I guess the most simple way to test this is to disable the resampling function in ALSA. Is this covered in the graphic configuration tool, or do I have to perform some command line exercise?

ldolse
Posts: 367
Joined: Fri 23 Oct 2009, 16:33

Re: Resampling

#170 Post by ldolse »

Magellan wrote:My USB DAC also accepts SPDIF. I know it accepts 24 bit 192 kHz over SPDIF. I am not sure however, if it also accepts the same bit- and samplerate over USB. I guess the most simple way to test this is to disable the resampling function in ALSA. Is this covered in the graphic configuration tool, or do I have to perform some command line exercise?
16/48 over USB is a strange limitation if the SPDIF supports up to 24/192. Usually the limitations are based on what class of USB audio the DAC supports - Class 1 is limited to 24/96, Class 2 can go up to 24/192. 16/48 is generally only seen for really inexpensive/old sound devices which were designed for computer only usage (as 16/48 has historically been the default computer bitrate)

Disabling auto-resampling isn't covered in the Wizard, as it's not something a user would typically do. It would probably require editing some ALSA files as well as mpd.conf, I'm not 100% sure on what the steps would be. It would probably be easier to just Google the model of your DAC and see what the USB interface supports.

Info on mpd.conf edits here: http://mpd.wikia.com/wiki/Tuning

Magellan
Posts: 17
Joined: Tue 06 Mar 2012, 09:53

Re: Resampling

#171 Post by Magellan »

ldolse wrote:
Magellan wrote:My USB DAC also accepts SPDIF. I know it accepts 24 bit 192 kHz over SPDIF. I am not sure however, if it also accepts the same bit- and samplerate over USB. I guess the most simple way to test this is to disable the resampling function in ALSA. Is this covered in the graphic configuration tool, or do I have to perform some command line exercise?
16/48 over USB is a strange limitation if the SPDIF supports up to 24/192. Usually the limitations are based on what class of USB audio the DAC supports - Class 1 is limited to 24/96, Class 2 can go up to 24/192. 16/48 is generally only seen for really inexpensive/old sound devices which were designed for computer only usage (as 16/48 has historically been the default computer bitrate)

Disabling auto-resampling isn't covered in the Wizard, as it's not something a user would typically do. It would probably require editing some ALSA files as well as mpd.conf, I'm not 100% sure on what the steps would be. It would probably be easier to just Google the model of your DAC and see what the USB interface supports.

Info on mpd.conf edits here: http://mpd.wikia.com/wiki/Tuning
The problem is my DAC is built by a one man company, a very small company. It is built into a preamp, and it sounds wonderful, but it is not possible to get any relevant info about it over the internet. I know however that it´s DAC chip is a Cirrus Logic CS4398 stereo audio 24-bit/192 kHz digital/analog converter system.
I use MPod as a client, and it says the FLAC file is 96 kHz during playback, but I don´t know if it is reading the input or output.
Is there a terminal command which can display what samplerate and bitrate are put into the dac?

ldolse
Posts: 367
Joined: Fri 23 Oct 2009, 16:33

Re: Resampling

#172 Post by ldolse »

Magellan wrote:Is there a terminal command which can display what samplerate and bitrate are put into the dac?
I'm not sure if you can get it with your card. You can try a command like this:

Code: Select all

cat /proc/asound/card1/pcm0p/sub0/hw_params
But you'll need to change card1/pcm0p/sub0 to match the hardware of your actual card. Double-tap the tab key after each slash to see what options are available to you - running cat on the different items will provide you with a variety of debug information about your card. Some of this level of debugging is disabled in mpdPup's kernel, but a lot of detail is still there.

Dynobot
Posts: 44
Joined: Wed 05 Dec 2012, 12:04

#173 Post by Dynobot »

Hi there Idolse

I know we have all been shooting tweaks etc at you...here is an easy way to pretty much get every Linux audio player tweak.

Download Soundchcks squeezebox touch tool box on a linux machine and open it up with a text editor.

You will find not only the prioritization tweaks I use but network tweaks and kernel tweaks etc. No need to try to re-invent the wheel.

Personally I don't like kernel tweaks and network tweaks seem to have a very minimal benefit. But either way pretty much everything is there.

That way you can incorporate all or some into Mpdpup and let a small group of testers, test out the sound and benefit. If your ears and your testers ears give a certain tweak the thumbs up then its a go. Better yet if you have time or the inclination you can allow users to toggle them on/off or choose values during set-up.

Best regards

jrling
Posts: 47
Joined: Wed 27 Jun 2012, 13:51

#174 Post by jrling »

Excellent suggestion Dynobot. Put me down as a willing tester.

I would welcome the inclusion of some of the Linux utils that are required for Soundchck's Toolbox tweaks in the mpdPup build, even if ldolse has not got the time to include the actual tweaks himself in the set-up wizard.

Dynobot
Posts: 44
Joined: Wed 05 Dec 2012, 12:04

#175 Post by Dynobot »

Hey jrling

Go ahead and download the file, then open it up with a text editor. You can actually cut and paste some of it in the script you put in the Mpdpup.

However before we go too far with this I would like to Publicly thank Soundcheck for his time and efforts with compiling all these tweaks. Soundcheck has spent a long time working with Linux and deserves all the credit.

jrling
Posts: 47
Joined: Wed 27 Jun 2012, 13:51

#176 Post by jrling »

Dynobot - I have just downloaded it and viewed in text editor.

Have to say that I found many or most of Soundcheck's code to be very Touch specific. Hardly surprising there. But so much so, that I was finding difficulty in finding any code that would transfer safely or effectively for mpdPup, but have to admit that I am no Linux expert. No doubt ldolse can comment.

ldolse has produced an excellent slimmed down targeted Linux build; it is inevitably not going to have the same kernel or approach as Touch code and therefore will not transfer. Please correct me if I am wrong. Even better point all of us to portions of Touch Toolbox that would just copy & paste across and work 'out of the (tool)box'. I assume that you have done so yourself.

Thanks as always for your suggestions and I am also a fan of Soundcheck in many of his excellent postings on all sorts of hi-fi adventures.

Dynobot
Posts: 44
Joined: Wed 05 Dec 2012, 12:04

#177 Post by Dynobot »

Hi jrling
On second thought I dont think I should post whats inside the file without permission.

bonalux
Posts: 22
Joined: Wed 20 Jun 2012, 11:02

Serial port control for MPD

#178 Post by bonalux »

Hi all, i've got a question for Idolse: did you think that is possible to feed some basic commands (such track skip, stop, play and eventually read some informations) to mpd via a rs-232 serial port? For my dac i'm building an mcu to control some function and to have ir remote control and since the alix board has a serial port this idea hitted me, the mcu i'm using can output to rs232, even a web site with some infos can be useful.

Another question, since i don't use it ATM, can i disable albumbler or the database updating it is doing at startup?

Thank you very much, best regards.

luisb
Posts: 25
Joined: Sun 30 Sep 2012, 13:52

#179 Post by luisb »

Hi all
What would be the best setup for MPDPUP?
I have tryed:
1-Local storage with SSD, just usb DAC connected
2-Network Wifi, server-player, storage on SSD server
3-Network Ethernet server-player, storage on SSD server
4-Network Ethernet server-player, storage on server external USB drive
By far, option 1 gave the best results, bigger soundstage, dynamics and musician identification. The worst was with wifi, noisy and stops on HD files, almost unlistenable.
Have not tryed other minimalistic options for player hardware. They make sense and would like to know your opinion/test results. How does cpu and memory performance affects sound? high/low cost gear?
Best regards

TPA Buffalo 3/waveio, AI MK III Tube modded monoblocks, Sonus Faber Grand Piano, Asus EEpc for server, Aspire One low end (with 30 Gb SSD and 1.5 Gb memory upgrade) for player, Ethernet connection direct with RJ45 cross cable.

jrling
Posts: 47
Joined: Wed 27 Jun 2012, 13:51

#180 Post by jrling »

Option 1!
I have that with SSD storing the music and WaveIO and it is fantastic.

I cannot comment on your other options, but I think they would be less good as network activity interference to the core process of outputting a consistent noise-free music stream, cannot be better?

I set mpdPup to load 100% into RAM. 4GB Ram in my case. The SSD then never comes into play.

I have a modest dual core Atom 1.6 Ghz processor (D510 mobo) and the beauty of mpdPup is that with its minimalist OS approach, it never gets stressed.

Happy Listening!

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