PHP - Google Speech API:找不到'Google\Cloud\Speech\SpeechClient‘类

Question

我希望有人能帮我弄清楚如何运行google的speech to text api。

https://github.com/GoogleCloudPlatform/php-docs-samples/tree/master/speech/api

我尝试运行的特定代码是:src/function/transcribe_sync.php

在末尾添加一行以调用该函数：

transcribe_sync("mono.flac", 'en-US');

它找不到依赖项。我一直在玩composer，但一直没能弄明白。

下面是错误：

php transcribe_sync.php
PHP Fatal error:  Uncaught Error: Class 'Google\Cloud\Speech\SpeechClient' not found in /home/bhaag/Documents/php-docs-samples-master/speech/api/src/functions/transcribe_sync.php:45
Stack trace:
#0 /home/bhaag/Documents/php-docs-samples-master/speech/api/src/functions/transcribe_sync.php(55): Google\Cloud\Samples\Speech\transcribe_sync('mono.flac', 'en-US')
#1 {main}
  thrown in /home/bhaag/Documents/php-docs-samples-master/speech/api/src/functions/transcribe_sync.php on line 45

下面是我的composer.json文件：

{
    "require": {
        "google/cloud-speech": "^0.2",
        "google/cloud-storage": "^1.0",
        "google/gax": "^0.8.1",
        "google/proto-client-php": "^0.10.0",
        "symfony/console": "^3.0",
        "php-ffmpeg/php-ffmpeg": "^0.9.3"
    },
    "autoload": {
        "psr-4": {
            "Google\\Cloud\\Samples\\Speech\\": "src/"
        },
        "files": [
            "src/functions/streaming_recognize.php",
            "src/functions/transcribe_async.php",
            "src/functions/transcribe_async_gcs.php",
            "src/functions/transcribe_sync.php",
            "src/functions/transcribe_sync_gcs.php"
        ]
    },
    "require-dev": {
        "phpunit/phpunit": "~4"
    }
}

我已经能够运行完整的speech示例，所以我知道我已经正确设置了所有凭据，但是使用完整示例(主目录中的speech.php)似乎真的很难理解。

我是不是走错路了？谢谢你的帮助！