Bad A2DP Performance
montgoss at gmail.com
Wed Aug 6 14:50:04 CEST 2008
I don't get nearly as bad performance as the OP. But it does make a
difference how close I hold the Freerunner to my headset. With it
just a few inches away, I get a glitch in the sound every 10 - 20
seconds. If I set it on the table in front of me about 2.5 - 3 feet
from the headset, I get constant glitches. I also noticed what seem
like dropped packets or sync issues. The song would just ahead by a
second or so every once in a while. No clue what causes that.
Here are my versions:
bluez-utils - 3.23-r4 -
bluez-utils-alsa - 3.23-r2 -
bluez-utils-compat - 3.23-r2 -
I checked top while I was playing. madplay was at about 18% usage and
aplay took another 12%. If I just used aplay with a wav, it uses
Is gstreamer what openmoko-mediaplayer uses? Cause that wouldn't even
play sound. Not sure what that is doing (obviously my goal would be
for the mediaplayer to play to the BT headset).
I noticed in the ticket a comment about trying it at 16 KHz sample
rate. So, I played the same song with that sample rate. It performed
much better. Of course, it sounds like crap... But I only got a few
stutters/glitches. It was fairly bearable. I actually listened to
the whole song and I noticed the following output:
Playing WAVE 'stdin' : Signed 16 bit Little Endian, Rate 16000 Hz, Stereo
6746 frames decoded (0:02:56.2), +0.6 dB peak amplitude, 36 clipped samples
If I play the same clip at the same distance, but at the original 44.1
KHz, it's unbearably glitchy. I get:
Playing WAVE 'stdin' : Signed 16 bit Little Endian, Rate 44100 Hz, Stereo
6746 frames decoded (0:02:56.2), +0.6 dB peak amplitude, 187 clipped samples
On Tue, Aug 5, 2008 at 11:17 PM, Brad Midgley <bmidgley at gmail.com> wrote:
> On Tue, Aug 5, 2008 at 1:03 PM, Daniel Benoy <daniel at benoy.name> wrote:
>> I reported a problem to the openmoko bug tracker a little while ago and I haven't received any feedback yet. I'm hoping I will get more feedback here.
> there are two sources of possible trouble for quality, cpu load and
> timing of bluetooth frames.
> The cpu is not likely the problem on neo. When driving it through the
> alsa driver, the neo1973 had really good a2dp performance even on
> older versions of bluez-utils, much better than the TI cpus (eg in the
> n800). Did you check the cpu load while playing? I don't have a
> freerunner, but the cpu is supposed to only be an improvement over the
> btw, what version of bluez-utils is in the system?
> an aside, the gstreamer plugin has had a performance issue that burns
> a lot of cpu. I never did isolate it to either the encoder or
> transmission components. It isn't likely you're using the gstreamer
> route unless you specifically set out to do it that way.
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