Google Speech API 아무것도 출력이 되지 않는 에러

해결방법
ffmpeg로 변환을 시킨다.
sample_rate_hertz가 16000으로 설정했기 때문에 변활시킬 때 16000으로 바꿔주어야 한다.
ffmpeg -i audio_file.mp4 -acodec pcm_s16le -ac 1 -ar 16000 audio_file.wav

예제 코드

def transcribe_file(speech_file):

    """Transcribe the given audio file."""

    from google.cloud import speech

    from google.cloud.speech import enums

    from google.cloud.speech import types

    client = speech.SpeechClient()

    with io.open(speech_file, 'rb') as audio_file:

        content = audio_file.read()

    audio = types.RecognitionAudio(content=content)

    config = types.RecognitionConfig(

        encoding=enums.RecognitionConfig.AudioEncoding.LINEAR16,

        sample_rate_hertz=16000,

        language_code='ko-KR')

    response = client.recognize(config, audio)

    print("test2")

    # Each result is for a consecutive portion of the audio. Iterate through

    # them to get the transcripts for the entire audio file.

    for result in response.results:

        print("test3")

        # The first alternative is the most likely one for this portion.

        print(u'Transcript: {}'.format(result.alternatives[0].transcript))

speech_file = "audio_file.wav"

transcribe_file(speech_file)

# google speech api