BUG: WAVEHDR.dwBytesRecorded Set to Zero in Win32s
PSS ID Number: 147430
Article Last Modified on 3/10/1999
The information in this article applies to:
This article was previously published under Q147430
SYMPTOMS
When you are using the Multimedia low-level Wave input functions in Win32s
for recording purposes, the dwBytesRecorded member of the WAVEHDR structure
is set to zero when you handle the MM_WIM_DATA message.
CAUSE
Win32s does not copy the dwBytesRecorded member as it should when handling
the MM_WIM_DATA message.
RESOLUTION
You will have to call waveInUnprepareHeader() before you examine the
dwBytesRecorded member in the WAVEHDR structure when you are handling the
MM_WIM_DATA message. Then you will get the correct result.
Note that the dwBytesRecorded value will be non-zero when you handle the
MM_WIM_DATA message the second time or later. This non-zero value is still
incorrect as it corresponds to the value of the dwBytesRecored from the
previous attempt. Therefore, you should always call waveInUnprepareHeader()
to get the correct result from dwBytesRecorded member in the MM_WIM_DATA
message. This means you will need to call waveInPrepareHeader() again if
recording is continued and the buffer is sent back to the driver.
STATUS
Microsoft has confirmed this to be a bug in the Microsoft products listed
at the beginning of this article. We are researching this problem and will
post new information here in the Microsoft Knowledge Base as it becomes
available.
Additional query words: win32s winmm low level wave
Keywords: kbmm KB147430
Technology: kbWin32s130 kbWin32sSearch