samples: Infinite Stream recognition (#1297)

* Infinite Stream recognition

* Infinite Stream recognition - Updates after review

* Infinite Stream recognition - Updates after review

* Infinite Stream recognition - Updates after review

Author: nirupa-kumar

speech/snippets/src/main/java/com/example/speech/InfiniteStreamRecognize.java

@@ -0,0 +1,181 @@
+/*
+ * Copyright 2018 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.example.speech;
+
+// [START speech_transcribe_infinite_streaming]
+import com.google.api.gax.rpc.ClientStream;
+import com.google.api.gax.rpc.ResponseObserver;
+import com.google.api.gax.rpc.StreamController;
+import com.google.cloud.speech.v1.RecognitionConfig;
+import com.google.cloud.speech.v1.SpeechClient;
+import com.google.cloud.speech.v1.SpeechRecognitionAlternative;
+import com.google.cloud.speech.v1.StreamingRecognitionConfig;
+import com.google.cloud.speech.v1.StreamingRecognitionResult;
+import com.google.cloud.speech.v1.StreamingRecognizeRequest;
+import com.google.cloud.speech.v1.StreamingRecognizeResponse;
+import com.google.protobuf.ByteString;
+import java.util.ArrayList;
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.LinkedBlockingQueue;
+import javax.sound.sampled.AudioFormat;
+import javax.sound.sampled.AudioSystem;
+import javax.sound.sampled.DataLine;
+import javax.sound.sampled.DataLine.Info;
+import javax.sound.sampled.TargetDataLine;
+
+public class InfiniteStreamRecognize {
+
+  // Creating shared object
+  private static volatile BlockingQueue<byte[]> sharedQueue = new LinkedBlockingQueue();
+  private static TargetDataLine targetDataLine;
+  private static int BYTES_PER_BUFFER = 6400; // buffer size in bytes
+
+  public static void main(String... args) {
+    try {
+      infiniteStreamingRecognize();
+    } catch (Exception e) {
+      System.out.println("Exception caught: " + e);
+    }
+  }
+
+  /** Performs infinite streaming speech recognition */
+  public static void infiniteStreamingRecognize() throws Exception {
+
+    // Microphone Input buffering
+    class MicBuffer implements Runnable {
+
+      @Override
+      public void run() {
+        System.out.println("Start speaking...Press Ctrl-C to stop");
+        targetDataLine.start();
+        byte[] data = new byte[BYTES_PER_BUFFER];
+        while (targetDataLine.isOpen()) {
+          try {
+            int numBytesRead = targetDataLine.read(data, 0, data.length);
+            if ((numBytesRead <= 0) && (targetDataLine.isOpen())) {
+              continue;
+            }
+            sharedQueue.put(data.clone());
+          } catch (InterruptedException e) {
+            System.out.println("Microphone input buffering interrupted : " + e.getMessage());
+          }
+        }
+      }
+    }
+
+    // Creating microphone input buffer thread
+    MicBuffer micrunnable = new MicBuffer();
+    Thread micThread = new Thread(micrunnable);
+    ResponseObserver<StreamingRecognizeResponse> responseObserver = null;
+    try (SpeechClient client = SpeechClient.create()) {
+      ClientStream<StreamingRecognizeRequest> clientStream;
+      responseObserver =
+          new ResponseObserver<StreamingRecognizeResponse>() {
+
+            ArrayList<StreamingRecognizeResponse> responses = new ArrayList<>();
+
+            public void onStart(StreamController controller) {}
+
+            public void onResponse(StreamingRecognizeResponse response) {
+              responses.add(response);
+              StreamingRecognitionResult result = response.getResultsList().get(0);
+              // There can be several alternative transcripts for a given chunk of speech. Just
+              // use the first (most likely) one here.
+              SpeechRecognitionAlternative alternative = result.getAlternativesList().get(0);
+              System.out.printf("Transcript : %s\n", alternative.getTranscript());
+            }
+
+            public void onComplete() {
+              System.out.println("Done");
+            }
+
+            public void onError(Throwable t) {
+              System.out.println(t);
+            }
+          };
+
+      clientStream = client.streamingRecognizeCallable().splitCall(responseObserver);
+
+      RecognitionConfig recognitionConfig =
+          RecognitionConfig.newBuilder()
+              .setEncoding(RecognitionConfig.AudioEncoding.LINEAR16)
+              .setLanguageCode("en-US")
+              .setSampleRateHertz(16000)
+              .build();
+      StreamingRecognitionConfig streamingRecognitionConfig =
+          StreamingRecognitionConfig.newBuilder().setConfig(recognitionConfig).build();
+
+      StreamingRecognizeRequest request =
+          StreamingRecognizeRequest.newBuilder()
+              .setStreamingConfig(streamingRecognitionConfig)
+              .build(); // The first request in a streaming call has to be a config
+
+      clientStream.send(request);
+
+      try {
+        // SampleRate:16000Hz, SampleSizeInBits: 16, Number of channels: 1, Signed: true,
+        // bigEndian: false
+        AudioFormat audioFormat = new AudioFormat(16000, 16, 1, true, false);
+        DataLine.Info targetInfo =
+            new Info(
+                TargetDataLine.class,
+                audioFormat); // Set the system information to read from the microphone audio
+        // stream
+
+        if (!AudioSystem.isLineSupported(targetInfo)) {
+          System.out.println("Microphone not supported");
+          System.exit(0);
+        }
+        // Target data line captures the audio stream the microphone produces.
+        targetDataLine = (TargetDataLine) AudioSystem.getLine(targetInfo);
+        targetDataLine.open(audioFormat);
+        micThread.start();
+
+        long startTime = System.currentTimeMillis();
+
+        while (true) {
+
+          long estimatedTime = System.currentTimeMillis() - startTime;
+
+          if (estimatedTime >= 55000) {
+
+            clientStream.closeSend();
+            clientStream = client.streamingRecognizeCallable().splitCall(responseObserver);
+
+            request =
+                StreamingRecognizeRequest.newBuilder()
+                    .setStreamingConfig(streamingRecognitionConfig)
+                    .build();
+
+            startTime = System.currentTimeMillis();
+
+          } else {
+            request =
+                StreamingRecognizeRequest.newBuilder()
+                    .setAudioContent(ByteString.copyFrom(sharedQueue.take()))
+                    .build();
+          }
+
+          clientStream.send(request);
+        }
+      } catch (Exception e) {
+        System.out.println(e);
+      }
+    }
+  }
+}
+// [END speech_transcribe_infinite_streaming]