[Bug 33105] New: un/plugging earphone while playing kills sound on MacOS

[wine-bugs at winehq.org]

http://bugs.winehq.org/show_bug.cgi?id=33105

             Bug #: 33105
           Summary: un/plugging earphone while playing kills sound on
                    MacOS
           Product: Wine
           Version: 1.5.25
          Platform: x86
        OS/Version: Mac OS X
            Status: NEW
          Severity: normal
          Priority: P2
         Component: mmdevapi
        AssignedTo: wine-bugs at winehq.org
        ReportedBy: hoehle at users.sourceforge.net
    Classification: Unclassified


I had observed earlier that mplayer stopped playing audio when plugging
earphones into my Mac Mini.  Running the interactive (audible) mmdevapi render
tests shows the likely culprit.

AudioQueueGetCurrentTime fails during approximately 500ms while the Mac is
dynamically reconfiguring its audio pipeline following the plug operation.

243251.428:trace:coreaudio:get_current_aqbuffer_position 634 frames (relative)
243251.450:trace:coreaudio:AudioClient_GetCurrentPadding (0x12bae8)->(0x32fbf8)
243251.450:warn:coreaudio:get_current_aqbuffer_position Unable to get current
time: 73746f70
...
243251.936:warn:coreaudio:get_current_aqbuffer_position Unable to get current
time: 73746f70
243251.942:trace:coreaudio:AudioClient_GetCurrentPadding (0x12bae8)->(0x32fbf8)
243251.942:trace:coreaudio:get_current_aqbuffer_position No buffers queued

QueueStopped = 0x73746f70, // ASCII 'stop'

Apple's Audio Queue Services documentation does not mention that result code,
however some OSS projects do.
mono's Mac driver:
https://github.com/mono/maccore/blob/master/src/AudioToolbox/AudioQueue.cs
AudioStreamer.m:
http://code.metager.de/source/xref/ubuntu/one/ios-music/utilities/AudioStreamer.m
Upon encountering that error, the latter app simply repeats the last known
position (like our winealsa/oss drivers do).

The Wine bug is possibly in mmdevdrv.c:get_current_aqbuffer_position.  It
always struck me that there's some "return 0" not preceded by
"if(mode==BUFPOS_ABSOLUTE) /* add This->written_frames */"
As a consequence, GetPosition returns 0, which possibly breaks winmm, DSound
and anyone else using that API.

I have a patch series that revisits that function...

The render tests show that audible audio resumes normal operations past that
half second, so aborting the CA queue or returning an error to the application
(e.g. AUDCLNT_E_DEVICE_INVALIDATED) is to be avoided IMHO.  (Of course, adding
support of DEVICE_INVALIDATED to Wine's winmm and DSound is another task).

-- 
Configure bugmail: http://bugs.winehq.org/userprefs.cgi?tab=email
Do not reply to this email, post in Bugzilla using the
above URL to reply.
------- You are receiving this mail because: -------
You are watching all bug changes.