Lower the buffer size of the Opus decoder based on the data we're actual receiving. Handle invocations of the decoder with null data for packet loss indication.

jni/nv_opus_dec.c

@@ -30,7 +30,7 @@ int nv_opus_get_channel_count(void) {
 
 // This number assumes 2 channels at 48 KHz
 int nv_opus_get_max_out_shorts(void) {
-	return 5760*2;
+	return 512*nv_opus_get_channel_count();
 }
 
 // The Opus stream is 48 KHz
@@ -48,7 +48,7 @@ int nv_opus_decode(unsigned char* indata, int inlen, short* outpcmdata) {
 	// Decoding to 16-bit PCM with FEC off
 	// Maximum length assuming 48KHz sample rate
 	err = opus_decode(decoder, indata, inlen,
-		outpcmdata, 5760, 0);
+		outpcmdata, 512, 0);
 
 	return err;
 }

jni/nv_opus_dec_jni.c

@@ -1,5 +1,6 @@
 #include "nv_opus_dec.h"
 
+#include <stdlib.h>
 #include <jni.h>
 
 // This function must be called before
@@ -48,13 +49,19 @@ Java_com_limelight_nvstream_av_audio_OpusDecoder_decode(
 	jbyte* jni_input_data;
 	jshort* jni_pcm_data;
 
-	jni_input_data = (*env)->GetByteArrayElements(env, indata, 0);
 	jni_pcm_data = (*env)->GetShortArrayElements(env, outpcmdata, 0);
+	if (indata != NULL) {
+		jni_input_data = (*env)->GetByteArrayElements(env, indata, 0);
 
-	ret = nv_opus_decode(&jni_input_data[inoff], inlen, jni_pcm_data);
+		ret = nv_opus_decode(&jni_input_data[inoff], inlen, jni_pcm_data);
+
+		// The input data isn't changed so it can be safely aborted
+		(*env)->ReleaseByteArrayElements(env, indata, jni_input_data, JNI_ABORT);
+	}
+	else {
+		ret = nv_opus_decode(NULL, 0, jni_pcm_data);
+	}
 
-	// The input data isn't changed so it can be safely aborted
-	(*env)->ReleaseByteArrayElements(env, indata, jni_input_data, JNI_ABORT);
 	(*env)->ReleaseShortArrayElements(env, outpcmdata, jni_pcm_data, 0);
 
 	return ret;

src/com/limelight/nvstream/av/audio/AvAudioDepacketizer.java

@@ -11,7 +11,7 @@ public class AvAudioDepacketizer {
 	private LinkedBlockingQueue<AvShortBufferDescriptor> decodedUnits =
 			new LinkedBlockingQueue<AvShortBufferDescriptor>(15);
 	
-	private AvShortBufferPool pool = new AvShortBufferPool(512);
+	private AvShortBufferPool pool = new AvShortBufferPool(OpusDecoder.getMaxOutputShorts());
 	
 	// Sequencing state
 	private short lastSequenceNumber;
@@ -21,34 +21,11 @@ public class AvAudioDepacketizer {
 		pool.purge();
 	}
 	
-	public void decodeInputData(AvRtpPacket packet)
+	private void decodeData(byte[] data, int off, int len)
 	{
-		short seq = packet.getSequenceNumber();
-		
-		if (packet.getPacketType() != 97) {
-			// Only type 97 is audio
-			return;
-		}
-		
-		// Toss out the current NAL if we receive a packet that is
-		// out of sequence
-		if (lastSequenceNumber != 0 &&
-			(short)(lastSequenceNumber + 1) != seq)
-		{
-			System.out.println("Received OOS audio data (expected "+(lastSequenceNumber + 1)+", got "+seq+")");
-			
-			// Tell the decoder about this packet loss
-			//OpusDecoder.decode(null, 0, 0, null);
-		}
-		
-		lastSequenceNumber = seq;		
-		
-		// This is all the depacketizing we need to do
-		AvByteBufferDescriptor rtpPayload = packet.getNewPayloadDescriptor();
-
 		// Submit this data to the decoder
 		short[] pcmData = pool.allocate();
-		int decodeLen = OpusDecoder.decode(rtpPayload.data, rtpPayload.offset, rtpPayload.length, pcmData);
+		int decodeLen = OpusDecoder.decode(data, off, len, pcmData);
 		
 		if (decodeLen > 0) {
 			// Return value of decode is frames decoded per channel
@@ -66,6 +43,31 @@ public class AvAudioDepacketizer {
 		}
 	}
 	
+	public void decodeInputData(AvRtpPacket packet)
+	{
+		short seq = packet.getSequenceNumber();
+		
+		if (packet.getPacketType() != 97) {
+			// Only type 97 is audio
+			return;
+		}
+		
+		// Toss out the current NAL if we receive a packet that is
+		// out of sequence
+		if (lastSequenceNumber != 0 &&
+			(short)(lastSequenceNumber + 1) != seq)
+		{
+			System.out.println("Received OOS audio data (expected "+(lastSequenceNumber + 1)+", got "+seq+")");
+			decodeData(null, 0, 0);
+		}
+		
+		lastSequenceNumber = seq;
+		
+		// This is all the depacketizing we need to do
+		AvByteBufferDescriptor rtpPayload = packet.getNewPayloadDescriptor();
+		decodeData(rtpPayload.data, rtpPayload.offset, rtpPayload.length);
+	}
+	
 	public void releaseBuffer(AvShortBufferDescriptor decodedData)
 	{
 		pool.free(decodedData.data);