Openmoko Bug #2282: freerunner with gsmhandset-a7.state sends more quiet audio than nokia 6610i

[Openmoko Public Trac]

#2282: freerunner with gsmhandset-a7.state sends more quiet audio than nokia 6610i
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 Reporter:  lindi            |          Owner:  openmoko-kernel                   
     Type:  defect           |         Status:  new                               
 Priority:  normal           |      Milestone:                                    
Component:  System Software  |        Version:  unspecified                       
 Severity:  normal           |       Keywords:  alsa call quality gsmhandset.state
 Haspatch:  0                |      Blockedby:                                    
Estimated:                   |    Patchreview:                                    
 Blocking:                   |   Reproducible:                                    
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 I made a series of testcalls to objectively compare freerunner with
 gsmhandset-a7.state from http://docs.openmoko.org/trac/ticket/2121 to
 nokia 6610i. To me it seems that freerunner sends more quiet audio, maybe
 the default alsa state should be improved somehow?

 Test setup:
 1) laptop that plays test-message.flac using its internal speaker
 2) mobile phone that is 5 cm away from the laptop. In this test the phone
 is either GTA02V5 with buzzfix or nokia 6610i.
 3) linphone voip client connected to my VOIP provider
 4) What I do is: call the phone with linphone and play audio from laptop
 to the phone so that linphone can record what gets sent to GSM network.
 5) I did this test with both phones and in a quiet room and also in a room
 where a TV set provides extra background noise.

 Results:
 sox sample-3af07def.wav dummy.wav stat
 {{{
 Samples read:            314944
 Length (seconds):     39.368000
 Scaled by:         2147483647.0
 Maximum amplitude:     0.207062
 Minimum amplitude:    -0.191376
 Midline amplitude:     0.007843
 Mean    norm:          0.001523
 Mean    amplitude:     0.000122
 RMS     amplitude:     0.006678
 Maximum delta:         0.328094
 Minimum delta:         0.000000
 Mean    delta:         0.001737
 RMS     delta:         0.009205
 Rough   frequency:         1754
 Volume adjustment:        4.829
 }}}

 sox sample-61ca9657.wav dummy.wav stat

 {{{
 Samples read:            335755
 Length (seconds):     41.969375
 Scaled by:         2147483647.0
 Maximum amplitude:     0.546875
 Minimum amplitude:    -0.578186
 Midline amplitude:    -0.015656
 Mean    norm:          0.003382
 Mean    amplitude:     0.000151
 RMS     amplitude:     0.017334
 Maximum delta:         0.960968
 Minimum delta:         0.000000
 Mean    delta:         0.004671
 RMS     delta:         0.026990
 Rough   frequency:         1982
 Volume adjustment:        1.730
 }}}

 As you can see the maximum amplitude is
 10*log(0.546 /  0.2070)/log(10) = 4.2 dB higher with nokia than with
 freerunner.

-- 
Ticket URL: <https://docs.openmoko.org/trac/ticket/2282>
docs.openmoko.org <http://docs.openmoko.org/trac/>
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