Windows Audio / WaveInAddBuffer() blocks

My application records audio samples from a microphone connected to my PC. So I chose the Windows WaveInXXX API to do the job.

After reading the documentation I decided to avoid using the callback mechanism with WaveInProc to save me the hassle synchronizing the threads. The whole application is pretty big and I thought this would make debugging simpler. When the application requests a block of samples, I just iterate over my buffer queue, take one out, copy the data, unprepare it, prepare it and add it back to the buffer queue. Basic program structure looks like this, I hope it makes the basic program flow clear:


Now the problem appears: After some time (and I am unable to reproduce the exact condition), WaveInAddBuffer() causes a deadlock although it's in the same thread as all the rest. The header for the buffer that shall be added when the deadlock happens is prepared and dwFlags == WHDR_PREPARED == 2.

Any ideas what could cause this deadlock?


I have not seen such a problem, but a guess might be something like fragmentation related to all the unprepare/prepare cycles. They are not necessary. You can do the prepare once for each buffer and then unprepare when finished recording. (Prepare locks the buffer into physical memory.)

Need Your Help

Leaflet - Convert lat/lng to standard projection

angularjs leaflet geojson markerclusterer angular-leaflet-directive

How to convert coordinates from Leaflet coordinate system to coordinate system that Google uses (WGS-84?), if the data are in an external file (geojson)?

Cant get String out of Base64 encoded ByteArrayDataSource

java base64 bytearray inputstream datahandler

I have a String converted with org.apache.axis2.databinding.utils.ConverterUtil to a Base64Binary (ByteArrayDataSource inside a DataHandler).

About UNIX Resources Network

Original, collect and organize Developers related documents, information and materials, contains jQuery, Html, CSS, MySQL, .NET, ASP.NET, SQL, objective-c, iPhone, Ruby on Rails, C, SQL Server, Ruby, Arrays, Regex, ASP.NET MVC, WPF, XML, Ajax, DataBase, and so on.