#10045 BLOC 1.5-sof: XO-1.5 Camera activity choppy

[Zarro Boogs per Child]

#10045: XO-1.5 Camera activity choppy
---------------------------------------+------------------------------------
           Reporter:  wad              |       Owner:  dsd                              
               Type:  defect           |      Status:  new                              
           Priority:  blocker          |   Milestone:  1.5-software-update              
          Component:  record-activity  |     Version:  Development build as of this date
         Resolution:                   |    Keywords:  camera record XO-1.5             
        Next_action:  diagnose         |    Verified:  0                                
Deployment_affected:                   |   Blockedby:                                   
           Blocking:                   |  
---------------------------------------+------------------------------------
Changes (by Quozl):

  * keywords:  camera XO-1.5 => camera record XO-1.5
  * owner:  erikb => dsd
  * next_action:  reproduce => diagnose
  * component:  camera-activity => record-activity


Comment:

 Testing.  Symptoms assessed as follows:

  * in the Record activity, with Photo, Video or Audio tabs selected, but
 before the start button is pressed, in other words during the relay of
 live video from the camera to the screen, the frame rate is low and the
 frames are lagged, but the stream as a whole does keep up.  During this
 time X and Record processes consume all available CPU time.  The low frame
 rate and lag should be fixed when #9407 and #9325 are fixed,

  * in the Record activity, when a Video or Audio recording is started, the
 relay of live video from the camera to the screen begins to fall behind,
 the stream does not keep up.  The resulting recording is truncated, in the
 same way as reported in #9919 (os64 record hangs on termination of second
 audio recording).

 The second symptom appears to be caused by the first symptom, in that
 without available headroom the more complex stream during recording can't
 be sustained.

 However the streams created by Record when recording have additional
 complexity, since the stream is divided into both a display sink and a
 file sink.  This division doubles the data flow, which is required to keep
 up with the file sink rather than the display sink.  This problem might
 also be alleviated by dropping frames on the display sink path of the
 stream, but I've tried to do this and failed.  A temporary workaround
 might be to remove the display sink altogether, and I think an earlier
 version of Record may have done this.

-- 
Ticket URL: <http://dev.laptop.org/ticket/10045#comment:3>
One Laptop Per Child <http://laptop.org/>
OLPC bug tracking system