[GarfL]

Anyone have any tips on writing a client for MPD?  I can't stand GMPC, and the ones for Android tablet are a bit lacking.

Just the Database file view, the ability to add to playlist, and the playback controls would rock. If I could do this in a web application, even better, because that is what I know best.

[nyc_paramedic]

Anyone have any tips on writing a client for MPD?  I can't stand GMPC, and the ones for Android tablet are a bit lacking.

Just the Database file view, the ability to add to playlist, and the playback controls would rock. If I could do this in a web application, even better, because that is what I know best.

There are plenty of web clients (from full featured to bare bones) on the MPD wiki site. Maybe you could modify the source code to suit your needs?

Link: http://mpd.wikia.com/wiki/Clients#Web_Clients

I'd like to see a simple web based remote for the new Wi-Fi/web enabled Kindle touch. An MPD remote on an E-Ink screen would be nice.

[Alexdad54]

Just the Database file view, the ability to add to playlist, and the playback controls would rock. If I could do this in a web application, even better, because that is what I know best.

Following on from what Nick said, I'm using MPDroid and I believe  (if I understand your question correctly) that it offers all these controls. I'm using it on a rooted Nook Color tablet running a full Android OS.

[nyc_paramedic]

Following on from what Nick said, I'm using MPDroid and I believe  (if I understand your question correctly) that it offers all these controls. I'm using it on a rooted Nook Color tablet running a full Android OS.

Pic or screen shot available?
 

[GarfL]

MPDroid leaves a lot to be desired in my opinion. Especially when it can't order an album correctly by tracklist (it sorts by the integer value apparently). Also with long folder names, the display truncates and I cannot tell what version of a recording I am listening to. EDIT: I am using it on an Andriod Tablet, so screen size shouldn't be an issue.

I will take a look at the various web clients and see if there is anything I can work with.

[TomS]

Just wondering if anyone has tried Voyage MPD 0.8?

Can this be done in place or is it a new card build?

[nyc_paramedic]

Just wondering if anyone has tried Voyage MPD 0.8?

Can this be done in place or is it a new card build?

I set it up last night. Works great. MPD 0.16.5 is in there with needed bug fixes.

With a previous version of Voyage, the one that had the RT kernel, I was having occasional issues at the start of hi-res files. Bits of static or clicks.

With the standard kernel all is well. On this platform for 2 channel music, I don't think a real time kernel is required.

[Alexdad54]

Pic or screen shot available?

I'll take some pics this weekend of the basic MPDroid interface, the settings page and the file library page and post them. I haven't had any problem with the length of the file names so far but I haven't examined the track listings to see if there's a problem yet.

[Magnum]

I set it up last night. Works great. MPD 0.16.5 is in there with needed bug fixes.

With a previous version of Voyage, the one that had the RT kernel, I was having occasional issues at the start of hi-res files. Bits of static or clicks.

With the standard kernel all is well. On this platform for 2 channel music, I don't think a real time kernel is required.

I *strongly* disagree.
When I first installed Voyage MPD 0.8RC I thought that the SQ was good, almost great. I hadn´t played music for a couple of weeks, though. When I connected my QB-9 to my Mac mini (half-tweaked with Lion, BitPerfect or Pure Music, the usual stuff) I thought that it sounded quite a lot better. So it was back to the drawing board. I then installed Voyage MPD 0.75 and thought the sound was a little bit better, but I am not 100% sure as it was in the same neighborhood as 0.8 anyways. (I found out that 0.8 did not use HPET as default, but it is default in 0.75, maybe becaus the Alixes dont have a HPET)

I then downloaded a RT kernel, manually edited menu.lst to reflect the new kernel (or you could use Grub 2) and with the threadirqs boot option, and BAM the sound was now very clearly better than the Mac. I then tweaked the priorities, USB irq to RT (if you have more than 1 USB, you should only tweak the USB output connected to the USB DAC), the sound output thread of MPD to RT, and the IRQ daemon as RT along, Alsa as RT, with some other tweaks. I even disabled most of the services. It it now sooooo much better than the Mini that it is just scary. And it handles all samplerates, and autoswitches without the buggy implementation of Bitperfect, Pure Music. And the files even reside locally on the harddisk inside. (Since Lion SMB sharing does not work, but I will eventually reinstall SL or just use Samba 3 with Macports).

The next project is probably to install Voyage MPD with RT kernel on a Mac Mini with 8GB ram, SSD, and play from memory disk. I have confidence that this will smoke the competition, DIY or commercial, whatever the cost or implementation.

As for your problems using the RT kernel. I could be wrong, but if the RT Kernel had problems with Hi-Rez, then you might have not set the priorities and other things properly. Or if you are a Linux Audio Guru already and you are certain of our experiences, the only solution might be to move up from the Alixes (or similar) and go for something with more ompfh

[TomS]

I *strongly* disagree.
When I first installed Voyage MPD 0.8RC I thought that the SQ was good, almost great. I hadn´t played music for a couple of weeks, though. When I connected my QB-9 to my Mac mini (half-tweaked with Lion, BitPerfect or Pure Music, the usual stuff) I thought that it sounded quite a lot better. So it was back to the drawing board. I then installed Voyage MPD 0.75 and thought the sound was a little bit better, but I am not 100% sure as it was in the same neighborhood as 0.8 anyways. (I found out that 0.8 did not use HPET as default, but it is default in 0.75, maybe becaus the Alixes dont have a HPET)

I then downloaded a RT kernel, manually edited menu.lst to reflect the new kernel (or you could use Grub 2) and with the threadirqs boot option, and BAM the sound was now very clearly better than the Mac. I then tweaked the priorities, USB irq to RT (if you have more than 1 USB, you should only tweak the USB output connected to the USB DAC), the sound output thread of MPD to RT, and the IRQ daemon as RT along, Alsa as RT, with some other tweaks. I even disabled most of the services. It it now sooooo much better than the Mini that it is just scary. And it handles all samplerates, and autoswitches without the buggy implementation of Bitperfect, Pure Music. And the files even reside locally on the harddisk inside. (Since Lion SMB sharing does not work, but I will eventually reinstall SL or just use Samba 3 with Macports).

Could you reduce that to a set of plain English instructions we could follow to try this?

[Magnum]

Im sorry I will try again. I guess nyc_paramedic would understand...

[TomS]

Im sorry I will try again. I guess nyc_paramedic would understand...

Well there are plenty of us on this thread that aren't Linux hacks, but we manage to get by with a little help from our friends... and enjoy the Alix/Voyage very much.

[Magnum]

I *strongly* disagree.
When I first installed Voyage MPD 0.8RC I thought that the SQ was good, almost great. I hadn´t played music for a couple of weeks, though. When I connected my QB-9 to my Mac mini (half-tweaked with Lion, BitPerfect or Pure Music, the usual stuff) I thought that it sounded quite a lot better. So it was back to the drawing board. I then installed Voyage MPD 0.75 and thought the sound was a little bit better, but I am not 100% sure as it was in the same neighborhood as 0.8 anyways. (I found out that 0.8 did not use HPET as default, but it is default in 0.75, maybe becaus the Alixes dont have a HPET)

I then downloaded a RT kernel, manually edited menu.lst to reflect the new kernel (or you could use Grub 2) and with the threadirqs boot option, and BAM the sound was now very clearly better than the Mac. I then tweaked the priorities, USB irq to RT (if you have more than 1 USB, you should only tweak the USB output connected to the USB DAC), the sound output thread of MPD to RT, and the IRQ daemon as RT along, Alsa as RT, with some other tweaks. I even disabled most of the services. It it now sooooo much better than the Mini that it is just scary. And it handles all samplerates, and autoswitches without the buggy implementation of Bitperfect, Pure Music. And the files even reside locally on the harddisk inside. (Since Lion SMB sharing does not work, but I will eventually reinstall SL or just use Samba 3 with Macports).

The next project is probably to install Voyage MPD with RT kernel on a Mac Mini with 8GB ram, SSD, and play from memory disk. I have confidence that this will smoke the competition, DIY or commercial, whatever the cost or implementation.

As for your problems using the RT kernel. I could be wrong, but if the RT Kernel had problems with Hi-Rez, then you might have not set the priorities and other things properly. Or if you are a Linux Audio Guru already and you are certain of our experiences, the only solution might be to move up from the Alixes (or similar) and go for something with more ompfh

When I first installed Voyage MPD 0.8RC, I thought that the sound quality was good, almost great, but kinda boring and lifeless.
The Mac mini sounded quite a lot better. I then installed Voyage MPD 0.75 and thought that maybe it sounded a little better than 0.8 but far from the Mac mini.

I then downloaded a binary of the Real Time Linux Kernel 3.0.1 kernel. Grub, the Linux boot loader read from the  menu.lst file to what kernel to boot. I changed some parameters in the menu.lst file so that the Real Time Kernel would boot instead of the normal Kernel.

BAM! The sound now eclipsed the Mac mini.
I then tweaked the priorities of the different processes. On a couple of key processes i set the priority the highest, which is real time priority. RT would in this context mean "the highest priority, realtime priority", whereas RT kernel just means the Real Time Kernel.

MPD run as 4 or 5 threads and with a modified MPD binary you can set different priorities of the threads. I set the output thread of MPD to RT, the other threads should not run as RT priority as that will make the sound less good, and might produce some click and pops, and will f*** up the resampling process if MPD  needs to resample. I also set RT priority on the USB IRQ along with some other stuff. You need to be selective here and give the highest priority only to the processes that directly influence the sound.

A stripped down Linux distro is a good basis, just like a racing track is also a good basis. That means we can prioritize MPD as a Formula 1 car. And since a racing track doesnt have bumps and other things a Formula 1 car can be optimized for maximum speed. So higher speed would in the headless Linux Music Server terms mean better sound. Not everything can run at real time priority just like Formula 1 cars cant prioritize everything. Only the things that make it go fast is of importance.
(Yes, I am sorry if this does not make any sense )

After all this tweaking, my headless server now leave the Mac mini in the dust. In, fact, the Mac mini is now relegated to do duty as a HTPC running Win7.

HPET is a High Performance Event Timer.
From Wikipedia: The HPET can produce periodic interrupts at a much higher resolution than the RTC and is often used to synchronize multimedia streams, providing smooth playback and reducing the need to use other timestamp calculations such as an X86-based CPU's RDTSC instruction.

I am unsure if the Alixes support HPET. I also think that Alixes do not make *ultimate* MPD servers. They are a little underpowered even if only 10-20% of the CPU power is used for normal non-resampled playback. And they are quite complicated (even if they are small) in hardware which means more processes. But to be fair, I have not tried an Alix.

[TomS]

Thanks for more detail. So what hardware platform are you running Voyage on, the Mac Mini?

[nyc_paramedic]

When I first installed Voyage MPD 0.8RC, I thought that the sound quality was good, almost great, but kinda boring and lifeless...

... I also think that Alixes do not make *ultimate* MPD servers. They are a little underpowered even if only 10-20% of the CPU power is used for normal non-resampled playback. And they are quite complicated (even if they are small) in hardware which means more processes. But to be fair, I have not tried an Alix.

OK, before I start typing paragraphs about RT kernels and low latency, can I ask what hardware platform you used to set all this RT and IRQ stuff on?

Also, if an Alix uses only 10-20% decoding FLAC at even 24bit/192Khz then how exactly is it underpowered? It's got plenty of RAM as well. And how are the "quite complicated"? Have you seen the block diagram of the circuit? It's on the PC Engines website. It's very simple compared to the mess of even the smallest full featured mini-itx boards.

Can you post exactly what settings, with commands, you used on your Voyage with RT kernel? I'll give it a try on my spare/experimental Alix board and tell you what I think. Though, on an Alix with no-mini PCI cards installed (as mine is configured) and only 1 USB audio device attached, I don't know how messing with IRQ would help.

I do know that latency plays a huge role when <I>recording streams. But with playback, on a machine with decent RAM and buffers it should be a non-issue. Though, I'd be willing to listen to your changes with open ears.

You should try and Alix as well. It's very cheap and would make a great firewall/router with m0n0wall installed if it's not your cup of tea.

nick

[Magnum]

Hi NYC_paramedic.
My intention is not to argue. I was merely stating my opinion.
Everybody is free to try, but since your opinion weighs heavily (you are after all the thread starter), I feel that I had to chime in since my experience differs a lot. You might feel that the normal kernel is fine. Others might feel that Windows directsound/"default OSX" is fine. And some might think that there should not be any differences in sound as long the output is bitperfect. In theory our QB-9s should not even care that much since it is async. And so on.. Nobody has the ultimate answers on this topic.

Since some/most (if I understand correctly) RT functions are already included in mainline 3.0.0 kernel, it should also be easy to try for most people.

Maybe complicated was the wrong word to describe the Alix platform. It just feels that way with the BIOS, COM ports, PS2 ports and other legacy hardware that take up IRQs and/or needs more background processes running. It also does not support HPET, and the CPU is slow. All these things might or might not matter at all. All I can say is that an RT Kernel , for me, does not impose any problems. Soundwise, the normal Kernel was not in the same league. Since I have a Mac mini to compare to, I am positive that I am not imagining these things. (indeed it should not matter, since there really is a night and day difference)

I use an Apple TV 1G. Installing Linux is unfortunately not trivial on this platform. The ATV1 is great because you can put a HDD inside, even a modern SATA drive with the right adapter. Even though it is bigger than an Alix, it is not big by any means. It it still smaller than a the unibody minis, except they are really cheap and portable. It would work great at my sisters or parents house. They dont need do know anything technical once it is set up. They can just drag new songs into the Samba share and it will magically appear on their mPod/mPad, and it will play anything with ease and at the same time have the performance and sound quality to boot.

[nyc_paramedic]

Hi NYC_paramedic.
My intention is not to argue. I was merely stating my opinion.

First, hello. Second, We're not arguing. We're discussing. That's why I said I _would_ like to try the settings you made. If I hear a difference I'll agree with you.

 

Everybody is free to try, but since your opinion weighs heavily...

Not too heavily, I hope.  I don't consider myself a *guru*. I have been using Linux for the last 14 years but computers are not my profession.

I feel that I had to chime in since my experience differs a lot. You might feel that the normal kernel is fine.

That's fine; it's what the thread is for. I don't mind different opinions. I do think the normal kernel sounds very, very good.

In theory our QB-9s should not even care that much since it is async. And so on.. Nobody has the ultimate answers on this topic.

Agreed. The qb-9 might be async but who knows how it's affected in other ways from the computer it's connected to. EMI? RFI?

Since some/most (if I understand correctly) RT functions are already included in mainline 3.0.0 kernel, it should also be easy to try for most people.

Are you saying RT is *enabled* by default on shipping 3.0.0 kernels? I'll check. Sounds strange as most desktops users do not need an RT kernel running by default.  And even so, it might not be "easy to try for most" as MPD does not have RT support compiled in by default. You have to patch and recompile, if I remember correctly.

Maybe complicated was the wrong word to describe the Alix platform. It just feels that way with the BIOS, COM ports, PS2 ports and other legacy hardware that take up IRQs and/or needs more background processes running. It also does not support HPET, and the CPU is slow. All these things might or might not matter at all.

The alix 2d2 and 3d2 do not have a standard BIOS. It's a custom TinyBios written by the designer of the Alix boards for embedded use: http://www.pcengines.ch/tinybios.htm And it's Open Source! No "legacy" code there.

Also, there is no PS/2. Did you actually look at any Alix documentation or visit the PC Engines website? I find it strange that you make these claims when your Apple TV 1g has more (SATA, optical audio out, etc.) peripherals, same RAM on board and only a slightly faster processor: http://en.wikipedia.org/wiki/Apple_TV#Technical_specifications Note that, your Apple TV also has a built in 48watt switching power supply.

Are you able to disable the audio, video and other gadgets on the Apple TV? And merely unplugging the video cable from the Apple TV doesn't necessarily make it headless as the video circuitry still might be active.

And what other "legacy hardware" does the Alix have? Can you be more specific? It's a from scratch design whose purpose was low power and embedded design.

All I can say is that an RT Kernel , for me, does not impose any problems. Soundwise, the normal Kernel was not in the same league. Since I have a Mac mini to compare to, I am positive that I am not imagining these things. (indeed it should not matter, since there really is a night and day difference)

Just to be absolutely clear: You do not have an Alix. Correct? You are comparing RT kernel and MPD on Apple TV 1G and a Mac Mini with OS X on it. Is this correct? (Maybe English is not your first language? Let me know.)

I use an Apple TV 1G. Installing Linux is unfortunately not trivial on this platform. The ATV1 is great because you can put a HDD inside, even a modern SATA drive with the right adapter. Even though it is bigger than an Alix, it is not big by any means. It it still smaller than a the unibody minis, except they are really cheap and portable. It would work great at my sisters or parents house. They dont need do know anything technical once it is set up. They can just drag new songs into the Samba share and it will magically appear on their mPod/mPad, and it will play anything with ease and at the same time have the performance and sound quality to boot.

And that would make it even *more* difficult for some audiophile here to use the device as an MPD server. The Alix boards are very open to experimentation. Contrast that with just getting the USB 2.0 port working on the Apple TV: USB 2.0 (officially for diagnostic use only, though hackers have managed to allow connectivity of hard disks, mice, and keyboards),[73] infrared receiver, HDMI, component video, optical audio...

How much is an Apple TV 1g? Are they readily available for purchase by anyone without having to resort to Craigslist or eBay? Is it not discontinued? The Alix 3d2 is $99 USD and available worldwide; case is $11 USD.

They dont need do know anything technical once it is set up. They can just drag new songs into the Samba share and it will magically appear on their mPod/mPad

But the same *exact* argument can be made for the Alix. There's a bunch of people here who (i hope!) will attest to that. Once they edit mpd.conf and fstab and update the music database it's very stable. Just turn off when done listening and turn it back on when you want to listen again; the read only, entire OS in RAM makes it trivial. No shutdown command to issue, etc. It's so stable and great sounding that's it's almost boring.

It's also...
--easier to setup by newbies than a Apple TV
--on an open hardware platform
--without resorting to hacks or possibly committing a DRM felony
--to use any power supply or battery supply *without* getting out the soldering iron
--has an open TinyBios
--is most probably quieter than an AppleTV EMI/RFI wise
--has a stupendously simple hardware *embedded* design.
--has no extraneous peripherals compared to you overly laden Apple TV 1G

Again, I'm not arguing with you. I would like to try your settings if you post specific steps and details. I have 2 Alix boards here: 1 stable for and one for experimenting.

But again, you don't have an Alix, correct?

nick

[Magnum]

Sorry I dont have the time to multiquote.

No I dont have an Alix.
I am not negative towards them, and it was a not neccesarily a pro-atv post. 
You seem very defendant of the Alix,  but I am in no way advocating the use of the ATV instead of the Alix. I am already saying that it is not trivial to install Linux on the ATV. I am saying good things about the ATV as a finished and set up system. That does not mean the same cant be said about the Alix.

My point was mostly about the HDD. Alixes dont have a HDD, so that makes them a little less portable, and less sister/parent safe as you would need to set up samba on your PC/Mac (or samba 3 on Lion) or a NAS. Which means more telephone calls from them for support.
Btw. The Pentium M 1ghz CPU in the Apple TV is many times faster than the LX800: CPU arithmetic. Dhrystone 757MIPS. Whetstone 283MFlops (Equivalent to a Celeron 266-class CPU)

Anyways my post was about the use of the RT Kernel. Not discussing my platform of choice. You were asking what I used, so I answered. But we should get back on track.


The RT options are not enabled by default. You have to activate them with "threadirqs". If no difference heard, then switch back. Other settings will mostly be different for the Alix.

[nyc_paramedic]

Sorry I dont have the time to multiquote.

No I dont have an Alix.
I am not negative towards them, and it was a not neccesarily a pro-atv post. 
You seem very defendant of the Alix,  but I am in no way advocating the use of the ATV instead of the Alix. I am already saying that it is not trivial to install Linux on the ATV. I am saying good things about the ATV as a finished and set up system. That does not mean the same cant be said about the Alix.

My point was mostly about the HDD. Alixes dont have a HDD, so that makes them a little less portable, and less sister/parent safe as you would need to set up samba on your PC/Mac (or samba 3 on Lion) or a NAS. Which means more telephone calls from them for support.
Btw. The Pentium M 1ghz CPU in the Apple TV is many times faster than the LX800: CPU arithmetic. Dhrystone 757MIPS. Whetstone 283MFlops (Equivalent to a Celeron 266-class CPU)

Anyways my post was about the use of the RT Kernel. Not discussing my platform of choice. You were asking what I used, so I answered. But we should get back on track.


The RT options are not enabled by default. You have to activate them with "threadirqs". If no difference heard, then switch back. Other settings will mostly be different for the Alix.

Ok, so you don't have an Alix. I was just confused because statements you made did not match the Alix description. And no, I'm not very defendant of them. It does what *I* need it to do and that's all I really care about. Some people have loved the sound but still have gone back to Mac, Windows, whatever because the can't live without certain GUI features, iTunes interface, etc. And that's fine, too. But lets forget about that...

On HDD: Alix 2d2 has 44pin laptop disc header. Connect your favorite spinning disc or SSD and your off. Look:http://www.pcengines.ch/alix2d2.htm Want SATA? Use and Avantech mini-PCI SATA card on Alix 2d2 or 3d2; $40 bucks. I'll stick to using NFS over ethernet. 'Tis a much more elegant solution.

On RT: Please post *exactly* what I should so. Give me details so that I can replicate what you did and what you heard.

Many thanks.

[nyc_paramedic]

Btw. The Pentium M 1ghz CPU in the Apple TV is many times faster than the LX800: CPU arithmetic. Dhrystone 757MIPS. Whetstone 283MFlops (Equivalent to a Celeron 266-class CPU)

It doesn't matter.

The LX800, with 256MB RAM is *overkill* for play back of 2 channel music at 24bit/192Khz over USB. It's overkill for 32bit/384Khz playback over USB. With MPD's large audio buffers, it's optimized low latency daemon and it's client/server deisgn means there's no need for 1Ghz CPU's for the playback of 24/192 or 32/384 audio.