I'm trying to use this open source code to extract frames from mp4 in android:
https://github.com/PhilLab/Android-MediaCodec-Examples/blob/master/ExtractMpegFramesTest.java
The original code is written as a unit test file, that extends AndroidTestCase. So I changed the constructor to:
ExtractMpegFramesTest(Uri filename, android.content.Context context) throws Throwable {
INPUT_FILE = filename;
local_context = context;
//ExtractMpegFramesWrapper.runTest(this);
}
The commented out code is the original. I call the code as
try {
ExtractMpegFramesTest extractMpegFramesTest = new ExtractMpegFramesTest( currFileURI, this);
extractMpegFramesTest.testExtractMpegFrames();
} catch (Exception e) {
e.printStackTrace();
} catch (Throwable throwable) {
throwable.printStackTrace();
}
Using the debugger, I see that it opens the file via MediaExtractor. It goes through a few iterations and throws an exception: java.lang.RuntimeException: frame wait timed out. It runs 5 frames and on the 6th it times out on this call; outputSurface.awaitNewImage(); (line 297)
original code:
public void awaitNewImage() {
final int TIMEOUT_MS = 100000;
synchronized (mFrameSyncObject) {
while (!mFrameAvailable) {
try {
// Wait for onFrameAvailable() to signal us. Use a timeout to avoid
// stalling the test if it doesn't arrive.
mFrameSyncObject.wait(TIMEOUT_MS);
if (!mFrameAvailable) {
// TODO: if "spurious wakeup", continue while loop
throw new RuntimeException("frame wait timed out");
}
} catch (InterruptedException ie) {
// shouldn't happen
throw new RuntimeException(ie);
}
}
mFrameAvailable = false;
}
So it looks like it does'nt get a new frame from the file and then times out.
From google searches, the error happens because I'm looping rather than using a thread. But that sample code uses a thread. I also tried increasing timeout, but same result. Any recommendations how I can go about debugging this?
EDIT: It looks like that code is seriously outdated. The class metadataretriever in the android api is much better. Here is a link to the discussion:
MediaMetadataRetriever.getFrameAtTime() returns only first frame
