opus: use fixed max size in Opus decoding as per documentation: If this is less…

opus: use fixed max size in Opus decoding as per documentation: If this is less than the maximum packet duration (120 ms; 5760 for 48kHz), this function will not be capable of decoding some packets.

extensions/opus/src/main/jni/opus_jni.cc

@@ -59,6 +59,7 @@ jint JNI_OnLoad(JavaVM* vm, void* reserved) {
 }
 
 static const int kBytesPerSample = 2;  // opus fixed point uses 16 bit samples.
+static const int kMaxOpusOutputPacketSizeSamples = 960 * 6;// Maximum packet size used in Xiph's opusdec.
 static int channelCount;
 static int errorCode;
 
@@ -101,7 +102,7 @@ DECODER_FUNC(jint, opusDecode, jlong jDecoder, jlong jTimeUs,
 
   const int32_t inputSampleCount =
       opus_packet_get_nb_samples(inputBuffer, inputSize, sampleRate);
-  const jint outputSize = inputSampleCount * kBytesPerSample * channelCount;
+  const jint outputSize = kMaxOpusOutputPacketSizeSamples * kBytesPerSample * channelCount;
 
   env->CallObjectMethod(jOutputBuffer, outputBufferInit, jTimeUs, outputSize);
   const jobject jOutputBufferData = env->CallObjectMethod(jOutputBuffer,
@@ -110,7 +111,7 @@ DECODER_FUNC(jint, opusDecode, jlong jDecoder, jlong jTimeUs,
   int16_t* outputBufferData = reinterpret_cast<int16_t*>(
       env->GetDirectBufferAddress(jOutputBufferData));
   int sampleCount = opus_multistream_decode(decoder, inputBuffer, inputSize,
-      outputBufferData, outputSize, 0);
+      outputBufferData, kMaxOpusOutputPacketSizeSamples, 0);
   // record error code
   errorCode = (sampleCount < 0) ? sampleCount : 0;
   return (sampleCount < 0) ? sampleCount