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Posts: 146 | Thanked: 15 times | Joined on Oct 2008
#1
Hi,
I want to write a *very* simple audio player in pygtk as part of a much bigger project related to ornitology and bird photography. My idea was to use mplayer in slave mode as backend to play the bird songs, since it has a volume gain feature (many bird songs records are quite low).

My problem is that mplayer crashes (both in my PC and in the N800) with the message: "MPlayer interrupted by signal 13 in module: unknown"

I was unable to find the meaning of this... Interestingly, mplayer does not crash if the same command is executed in the console.

This is the relevant part of my code:

os.popen('mplayer -slave -input file=/tmp/mpfifo '+self.file)

So:
1) Do you have an idea why mplayer is crashing?
2) If not, which other backend software with volume gain to use as backend?
3) Do you know how to use madplay as backend?
4) Any other software to use as backend, even without volume gain?

Thanks a lot,
L.
 
Posts: 58 | Thanked: 34 times | Joined on Dec 2007 @ the Lower Rainland
#2
You should try YouAmp. It allows you to adjust the gain from inside the program.
 
Posts: 146 | Thanked: 15 times | Joined on Oct 2008
#3
Originally Posted by silvermain View Post
You should try YouAmp. It allows you to adjust the gain from inside the program.
Sorry, perhaps I wasn't clear enough (or I didn't understand you?). I do not want (another) GUI player. I will do my own front end, as part of a much bigger program, and I already know how to use the default media player with my program.

I want exactly the opposite, a backend decoding audio software since I don't want to redo all the actual audio decoding. Mplayer would be perfect, but it just crashes.

Thanks!
L.
 
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Posts: 2,355 | Thanked: 5,249 times | Joined on Jan 2009 @ Barcelona
#4
gstreamer is the suggested backend for maemo. You'll also get DSP accelerated decoding this way.

I'm pretty sure there are python bindings for it.
 

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Posts: 146 | Thanked: 15 times | Joined on Oct 2008
#5
Originally Posted by javispedro View Post
gstreamer is the suggested backend for maemo. You'll also get DSP accelerated decoding this way.

I'm pretty sure there are python bindings for it.
Mmm... interesting. Do you know if gstreamer has automatic volume gain, like mplayer? In fact, do you know where I can read about it, in particular, the bindings?

BTW, I got mplayer working in slave mode. But still, you awoke my curiosity... probably gstreamer is indeed better.

Thanks a lot!!!
L.
 
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Posts: 2,355 | Thanked: 5,249 times | Joined on Jan 2009 @ Barcelona
#6
Originally Posted by luis View Post
Mmm... interesting. Do you know if gstreamer has automatic volume gain, like mplayer? In fact, do you know where I can read about it, in particular, the bindings?
I don't know if an automatic volume gain component exists -- sorry.
There's a nice pygst tutorial at http://pygstdocs.berlios.de/pygst-tutorial/index.html . Specially check http://pygstdocs.berlios.de/pygst-tutorial/playbin.html .

Originally Posted by luis View Post
BTW, I got mplayer working in slave mode. But still, you awoke my curiosity... probably gstreamer is indeed better.
It should be better, but seems using it may be more complex than your initial idea.

Last edited by javispedro; 2009-06-03 at 22:33.
 

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#7
Originally Posted by javispedro View Post
I don't know if an automatic volume gain component exists -- sorry.
There's a nice pygst tutorial at http://pygstdocs.berlios.de/pygst-tutorial/index.html . Specially check http://pygstdocs.berlios.de/pygst-tutorial/playbin.html .


It should be better, but seems using it may be more complex than your initial idea.
Probably not, since I don't want much more than that playbin.py. The volume gain may be a killer, though...

Thanks!!!!!

Best,
L.
 
Posts: 7 | Thanked: 3 times | Joined on May 2009
#8
Did you get to a working playbin for Maemo? I'd be interested.
My target is a 770.
 
Posts: 146 | Thanked: 15 times | Joined on Oct 2008
#9
Originally Posted by sciurius View Post
Did you get to a working playbin for Maemo? I'd be interested.
My target is a 770.
I've decided to go with mplayer because the automatic volume gain is crucial for me, and because it is simpler to implement.

Cheers,
L.
 
Posts: 146 | Thanked: 15 times | Joined on Oct 2008
#10
Well, I implemented the mplayer backend in slave mode, but it REALLY sucks. mplayer for maemo is highly broken.
I tried to get python-gst package for maemo4, but failed miserably.
Where can I find this?

Thanks!
L.
 
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