Here's my patch: http://trac.xbmc.org/ticket/10080
All current WIN32 versions of XBMC have a bug in the audio output code where:
If DirectSound ever returns PlayCursor and WriteCursor to be the same value
Then XBMC erroneously interpreted this to mean buffer empty instead of buffer full
Resulting in XBMC overwriting its entire output buffer, causing a skip one second ahead in both video and audio.
This rarely happens with regular sound drivers, but happens *constantly* with Virtual Audio Cable, making XBMC completely unusable on affected systems - audio and video skips constantly.
Using Virtual Audio Cable (VAC) is getting increasingly popular (as computers get more and more powerful) by allowing post-processing of audio before it leaves the computer, obsoleting outboard equipment in favour of software such as equalizers, more advanced dynamics compression and surround upmixing.
To reproduce the problem on any Windows XP SP2/SP3 system, install Virtual Audio Cable http://software.muzychenko.net/eng/vac.htm, set XBMC audio output to Virtual Cable 1, use VAC Audio Repeater to connect Virtual Cable 1 with your sound card, and try to watch video (or play audio) in XBMC. The first file you play may work, subsequent will skip constantly.
I just started using XBMC and was affected by this problem immediately, so I had to choice but to fix it
.
Best regards,
Leif Claesson
All current WIN32 versions of XBMC have a bug in the audio output code where:
If DirectSound ever returns PlayCursor and WriteCursor to be the same value
Then XBMC erroneously interpreted this to mean buffer empty instead of buffer full
Resulting in XBMC overwriting its entire output buffer, causing a skip one second ahead in both video and audio.
This rarely happens with regular sound drivers, but happens *constantly* with Virtual Audio Cable, making XBMC completely unusable on affected systems - audio and video skips constantly.
Using Virtual Audio Cable (VAC) is getting increasingly popular (as computers get more and more powerful) by allowing post-processing of audio before it leaves the computer, obsoleting outboard equipment in favour of software such as equalizers, more advanced dynamics compression and surround upmixing.
To reproduce the problem on any Windows XP SP2/SP3 system, install Virtual Audio Cable http://software.muzychenko.net/eng/vac.htm, set XBMC audio output to Virtual Cable 1, use VAC Audio Repeater to connect Virtual Cable 1 with your sound card, and try to watch video (or play audio) in XBMC. The first file you play may work, subsequent will skip constantly.
I just started using XBMC and was affected by this problem immediately, so I had to choice but to fix it
.Best regards,
Leif Claesson
