Add Speech API streaming sample. (#144)

* Add Speech API streaming example.

* Remove comment.

* Add test.

* Fix failing test.

* Rename variable.

Author: jmdobry

speech/package.json

@@ -9,9 +9,10 @@
     "node": ">=0.10.x"
   },
   "dependencies": {
-    "googleapis": "^7.1.0"
-  },
-  "devDependencies": {
-    "async": "^1.5.2"
+    "async": "^1.5.2",
+    "google-auto-auth": "^0.2.4",
+    "google-proto-files": "^0.2.4",
+    "googleapis": "^7.1.0",
+    "grpc": "^0.15.0"
   }
 }

speech/recognize_streaming.js

@@ -0,0 +1,138 @@
+// Copyright 2016, Google, Inc.
+// 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.
+
+'use strict';
+
+var async = require('async');
+var fs = require('fs');
+var path = require('path');
+var grpc = require('grpc');
+var googleProtoFiles = require('google-proto-files');
+var googleAuth = require('google-auto-auth');
+
+// [START proto]
+var PROTO_ROOT_DIR = googleProtoFiles('..');
+var PROTO_FILE_PATH = googleProtoFiles('cloud', 'speech', 'v1', 'cloud_speech.proto');
+
+var protoDescriptor = grpc.load({
+  root: PROTO_ROOT_DIR,
+  file: path.relative(PROTO_ROOT_DIR, PROTO_FILE_PATH)
+}, 'proto', {
+  binaryAsBase64: true,
+  convertFieldsToCamelCase: true
+});
+var speechProto = protoDescriptor.google.cloud.speech.v1;
+// [END proto]
+
+// [START authenticating]
+function getSpeechService (callback) {
+  var googleAuthClient = googleAuth({
+    scopes: [
+      'https://www.googleapis.com/auth/cloud-platform'
+    ]
+  });
+
+  googleAuthClient.getAuthClient(function (err, authClient) {
+    if (err) {
+      return callback(err);
+    }
+
+    var credentials = grpc.credentials.combineChannelCredentials(
+      grpc.credentials.createSsl(),
+      grpc.credentials.createFromGoogleCredential(authClient)
+    );
+
+    console.log('Loading speech service...');
+    var stub = new speechProto.Speech('speech.googleapis.com', credentials);
+    return callback(null, stub);
+  });
+}
+// [END authenticating]
+
+// [START construct_request]
+function getAudioFile (inputFile, callback) {
+  fs.readFile(inputFile, function (err, audioFile) {
+    if (err) {
+      return callback(err);
+    }
+    console.log('Got audio file!');
+    return callback(null, audioFile);
+  });
+}
+// [END construct_request]
+
+function main (inputFile, callback) {
+  var audioFile;
+
+  async.waterfall([
+    function (cb) {
+      getAudioFile(inputFile, cb);
+    },
+    function (_audioFile, cb) {
+      audioFile = _audioFile;
+      getSpeechService(cb);
+    },
+    // [START send_request]
+    function sendRequest (speechService, cb) {
+      console.log('Analyzing speech...');
+      var responses = [];
+      var call = speechService.recognize();
+
+      // Listen for various responses
+      call.on('error', cb);
+      call.on('data', function (recognizeResponse) {
+        if (recognizeResponse) {
+          responses.push(recognizeResponse);
+        }
+      });
+      call.on('end', function () {
+        cb(null, responses);
+      });
+
+      // Write the initial recognize reqeust
+      call.write(new speechProto.RecognizeRequest({
+        initialRequest: new speechProto.InitialRecognizeRequest({
+          encoding: 'LINEAR16',
+          sampleRate: 16000,
+          interimResults: false,
+          continuous: false,
+          enableEndpointerEvents: false
+        })
+      }));
+
+      // Write an audio request
+      call.write(new speechProto.RecognizeRequest({
+        audioRequest: new speechProto.AudioRequest({
+          content: audioFile
+        })
+      }));
+
+      // Signal that we're done writing
+      call.end();
+    }
+    // [END send_request]
+  ], callback);
+}
+
+// [START run_application]
+if (module === require.main) {
+  if (process.argv.length < 3) {
+    console.log('Usage: node recognize_streaming <inputFile>');
+    process.exit();
+  }
+  var inputFile = process.argv[2];
+  main(inputFile, console.log);
+}
+// [END run_application]
+
+exports.main = main;