IllegalStateException while reading from ShortBuffer in Unity Android
I'm working on a game in Unity where I need raw audio data from a media buffer. The following code is used as a plugin jar in Unity. It works on android 4.x with no problem. But when I try to run it on Android 5.0.1 or 5.1, I get the following exception, but only when I try to open aac or m4a files. Any suggestions?
This is the function where I read the sound buffer:
public short[] ReadNextSamples() {
if (sawOutputEOS) {
return new short[0];
}
int res;
while (true)
{
res = codec.dequeueOutputBuffer(info, kTimeOutUs);
if (res >= 0)
{
if (info.size > 0)
{
break;
}
else
{
codec.releaseOutputBuffer(res, false);
if ((info.flags & MediaCodec.BUFFER_FLAG_END_OF_STREAM)!= 0)
{
sawOutputEOS = true;
return new short[0];
}
}
}
}
int outputBufIndex = res;
ByteBuffer buf = codecOutputBuffers[outputBufIndex];
int sampleSize = info.size / 2;
short[] sampleValues = new short[sampleSize];
ShortBuffer shBuf = buf.asShortBuffer();
try {
shBuf.get(sampleValues, 0, sampleSize);
} catch (Exception e) {
//the exception is being thrown here
e.printStackTrace();
}
codec.releaseOutputBuffer(outputBufIndex, false);
if ((info.flags & MediaCodec.BUFFER_FLAG_END_OF_STREAM) != 0) {
sawOutputEOS = true;
}
return sampleValues;
}
An exception:
06-04 16:18:01.188: W/System.err(20884): java.lang.IllegalStateException: buffer is inaccessible
06-04 16:18:01.188: W/System.err(20884): at java.nio.DirectByteBuffer.checkIsAccessible(DirectByteBuffer.java:551)
06-04 16:18:01.188: W/System.err(20884): at java.nio.DirectByteBuffer.get(DirectByteBuffer.java:155)
06-04 16:18:01.188: W/System.err(20884): at java.nio.ByteBufferAsShortBuffer.get(ByteBufferAsShortBuffer.java:103)
06-04 16:18:01.190: W/System.err(20884): at com.pocketgames.musiverse.MediaDecoder.ReadNextSamples(MediaDecoder.java:112)
06-04 16:18:01.190: W/System.err(20884): at com.unity3d.player.ReflectionHelper.nativeProxyInvoke(Native Method)
06-04 16:18:01.190: W/System.err(20884): at com.unity3d.player.ReflectionHelper.a(Unknown Source)
06-04 16:18:01.190: W/System.err(20884): at com.unity3d.player.ReflectionHelper$1.invoke(Unknown Source)
06-04 16:18:01.190: W/System.err(20884): at java.lang.reflect.Proxy.invoke(Proxy.java:397)
06-04 16:18:01.190: W/System.err(20884): at $Proxy0.run(Unknown Source)
06-04 16:18:01.191: W/System.err(20884): at java.lang.Thread.run(Thread.java:818)
source to share
Basically you should use API level dependent code. I think you may have figured this out by now. But for documentation purposes you should use
ByteBuffer buf = codecOutputBuffers[outputBufIndex];
for API level <21
and
ByteBuffer buf = codec.getOutputBuffer(outputBufIndex);
for API level> = 21.
The code looks something like this:
final int version = Build.VERSION.SDK_INT;
ByteBuffer buf;
if (version >= 21) {
buf = codec.getOutputBuffer(outputBufIndex);
} else {
buf = codecOutputBuffers[outputBufIndex];
}
If you look at the source code of the class MediaCodec
, the code for getOutputBuffer
:
@Nullable
public ByteBuffer getOutputBuffer(int index) {
ByteBuffer newBuffer = getBuffer(false /* input */, index);
synchronized(mBufferLock) {
invalidateByteBuffer(mCachedOutputBuffers, index);
mDequeuedOutputBuffers.put(index, newBuffer);
}
return newBuffer;
}
So the error you got is related to acquiring a lock mBufferLock
, which might be required when implementing MediaCodec
for API level> = 21, and hence you will get an unavailable error. Hope this helps.
source to share
I ran into a similar problem in Android L and could be solved using the new MediaCodec API to get the buffer.
Instead
ByteBuffer buf = codecOutputBuffers[outputBufIndex];
you can use
ByteBuffer buf = codec.getOutputBuffer(outputBufIndex);
In my case, this solved the problem when accessing input buffers.
source to share