[Audacity-devel] 2hr Recording Bug fix now in CVS

[James C. <cr...@in...>]

I've tracked down a repeatable bug in recording on windows:

at 44100 Hz Mono takes 1hr 43 mins
at 96000 Hz Mono takes 48 mins
at 96000 Hz Stereo takes 23 mins.

for the record cursor to 'wrap around'.


in pa_win_mme.c

PaHost_UpdateStreamTime( PaWMMEStreamData *wmmeStreamData )

Was:
    wmmeStreamData->framesPlayed += ((long)mmtime.u.sample) -
wmmeStreamData->lastPosition;
    wmmeStreamData->lastPosition = (long)mmtime.u.sample;

Now:
    wmmeStreamData->framesPlayed += (long)((DWORD)mmtime.u.sample -
(DWORD)(wmmeStreamData->lastPosition));
    wmmeStreamData->lastPosition = (long)mmtime.u.sample;

I'm hoping this is the underlying cause of the recording bug that has been
reported to the list.



It would be a huge help if someone else with windows would try a 2hr
recording at 96000Hz Stereo before this patch, and then again after.
If they get the anticipated results, then I think we can safely close the
bug.

--James.

I also suspect this line
    delta = info.bytes - pahsc->pahsc_LastPosPtr;

in the linux version of
    Pa_UpdateStreamTime(PaHostSoundControl *pahsc)

Has the same problem,
  pahsc_LastPosPtr is an int
  if  info.bytes is a DWORD (I can't tell from the code I have)
then we need to (DWORD) cast pahsc_LastPosPtr to get
the correct delta in spite of wrap around.

--James.