Simple audio player with low power consumption
 

I have noticed that the built-in media player of the N900 uses 20-40% (average ~30%) of the CPU (pulseaudio & dbusfw) when playing simple MP3 files. Other media players are worse than that. Is so much power usage really needed or is there a more simple audio player? I can remember my times with an old Siemens S65 which was able to play MP3s while writing a SMS and listening a loong time and it had a very slow processor compared to the N900.

Re: Simple audio player with low power consumption
 

I've never seen very much strain on the battery by listening to mp3s on the sd card.
Batterylife seems to be only really dependent on network connections.

Re: Simple audio player with low power consumption
 

Plugging in headphones should help. It bypasses certain filtering passes. From what i've heard, it sounds like encoding the audio to 48 instead off 44 Hz would also help, because otherwise it has to be done on-the-fly. I'd be interested to see a comparison of playback time (or at least processor usage) with these two changes.

Something like what Tuomas did with ogg and mp3 for his testing on the ogg support. See his comments in this blog: http://tuomas.kulve.fi/blog/

Re: Simple audio player with low power consumption
 

That power usage isn't necessarily much, taken N900 is good at CPU throttling?

Re: Simple audio player with low power consumption
 

I am not having the CPU hog problem with the stock player. Between the two processes running, they total 12 to 14% of CPU. This is with playing 192kb and similar level VBR mp3's.

Re: Simple audio player with low power consumption
 

Maybe it is because of the stream but I lose 20-25% percent points of the battery every hour just by listening (display off).

Re: Simple audio player with low power consumption
 

This is weird and totally unusual. I can listen to at least a few hours without seeing any impact on the battery....

Re: Simple audio player with low power consumption
 

The CPU usage varies between using the speakers vs the headphones.
On mine

Headphones

14.3 % /usr/bin/mafw-dbus-wrapper mafw-gst-renderer
13.7 % /usr/bin/pulseaudio --system --high-priority

Speakers

14.3 % /usr/bin/mafw-dbus-wrapper mafw-gst-renderer
26.6 % /usr/bin/pulseaudio --system --high-priority

The reason is that Pulse-audio monitors the sound when using speakers to prevent it damaging them

Re: Simple audio player with low power consumption
 

I installed Music Player Daemon on my device and controlled it with my own client CuteMPC (https://garage.maemo.org/projects/cutempc/) and the total CPU usage was about 10% lower (and memory usage also a few MB less) than with the original player. There was some problems with sound (mutes every now and then), but I think that might be because I have something wrong with MPD configuration (wrong audio device or something).

Re: Simple audio player with low power consumption
 

Sounds great.
Any plans to release it to extras?

Re: Simple audio player with low power consumption
 

Yes I will put it in extras-devel sometime in the near future.

Re: Simple audio player with low power consumption
 

Now I configured MPD to use pulseaudio instead of alsa and the total CPU usage is actually couple of percents higher than with the original player... Not good :(

Re: Simple audio player with low power consumption
 

LOL and you expected something different?

You can either bypass pulseaudio and get the side effects of that (blocking other sounds) or use pulseaudio...

now, finding ways to patch and improve pulseaudio, that would be great!

Re: Simple audio player with low power consumption
 

It seems like FLAC (ogg-support) is the only format that plays fine and without hiccups on the N900 under some load, while Ogg-Vorbis plays worst. Honestly, the 770 was better at music playback than the N900 currently is!