Changes between Version 4 and Version 5 of AudioDebug

Timestamp:

Sep 25, 2017 9:17:42 AM (7 years ago)

Author:

pentagonik

Comment:

More stuff for 5.2 (.WAV file dumping, diagnosis).

AudioDebug

@@ -1 +1 @@
 = Investigating audio problems =
+
+== Overview ==
+
+To pinpoint the issue further, it first must be determined if the audio problems are on the guest or on the host side.
+For the host side there are a variety of so-called host audio drivers (backends) which are needed in order to support
+the host operating system playing back and recording audio from / to the guest (VM).
+
+'''Tip of the day''': Best is to copy & paste the following commands to avoid typing errors.
+
+
+== Dumping audio output ==
+
+Dumping guest audio output as .WAV (wave) files to the host is available since '''!VirtualBox 5.2'''. 
+For older !VirtualBox versions an instrumented (debug) build must be used (will be given on request).
+
+To enable dumping guest audio output, do the following:
+
+ 1. Make sure that the affected VM is not running anymore.
+ 2. Run
+{{{
+VBoxManage setextradata <Name-of-VM> "VBoxInternal2/Audio/Debug/Enabled" "true"
+}}}
+ 3. Start the affected VM again.
+
+Now, when performing any audio output on the guest (playback), there will be separate .WAV files created in the host's temporary directory.
+
+For Windows hosts this by default is '''C:\Windows\Temp''' or '''C:\Users\<username>\AppData\Local\Temp'''.
+For Linux / Solaris / MacOS hosts this by default is '''/tmp/'''. When in doubt, have a look at the '''$TMP''' or '''$TMPDIR''' environment variables respectively.
+
+The created .WAV files then can be played back with any regular media player on the host, e.g. VLC, MPlayer or Windows Media Player.
+
+=== Diagnosis ===
+[[br]]
+||= '''Playback in running VM''' =||= '''Dumped file(s)''' =||=     '''Diagnosis'''         =||
+|| Distorted                      ||       OK               || Host driver (backend) problem ||
+|| OK                             || Distorted              || Host mixing problem           ||
+|| Distorted                      || Distorted              || Device emulation problem      ||
+
 
 == Collecting information from the host ==
 
 As always when it comes to diagnosing problems with !VirtualBox the appropriate VBox.log is useful to have. To gather more verbose information about the actual audio state, please do the following:
-
-'''Tip of the day''': Best is to copy & paste the following commands to avoid typing errors.
 
  1. On '''Windows'''
@@ -23 +59 @@
 }}}
   * Start the !VirtualBox Manager.
- 2. On Linux/OS X/Solaris, stop the !VirtualBox manager and restart it by running the following from a terminal:
+ 2. On '''Linux/OS X/Solaris''', stop the !VirtualBox manager and restart it by running the following from a terminal:
 {{{
 VBOX_RELEASE_LOG=drv_host_audio.e.l.l2.l3.f+drv_audio.e.l.l2.l3.f+audio_mixer.e.l.l2.l3.f+dev_hda_codec.e.l.l2.l3.f+dev_hda.e.l.l2.l3.f+dev_ac97.e.l.l2.l3.f VirtualBox