Provide guidance on creating a header for `streaming_synthesize` in streaming_tts_quickstart.py

Bắt đầu với texttospeech/snippets/streaming_tts_quickstart.py quanh các dòng 46-48 và xem xét đặc tả WAV được liên kết. Xác định cách tạo header cho các phản hồi LINEAR16 24.000 Hz không có header, sau đó cập nhật sample để cung cấp hướng dẫn tạo ra âm thanh có thể phát được. Xác nhận rằng cách xử lý output tạo ra là rõ ràng đối với người dùng đang debug quá trình tổng hợp streaming.

From https://github.com/googleapis/google-cloud-python/issues/13405, the response to streaming_synthesize is headerless LINEAR16 audio with a sample rate of 24000.. The code sample below prints the size of the audio content but does not include the necessary header to actually play the audio.

https://github.com/GoogleCloudPlatform/python-docs-samples/blob/5e8e1788598a22f4dc7ceb13b0d62ef373406554/texttospeech/snippets/streaming_tts_quickstart.py#L46-L48

This may not be the purpose of the code sample, however having this extra information in the code sample will help with debugging customer issues such as https://github.com/googleapis/google-cloud-python/issues/13405.

I added code which includes the raw audio header, however there is likely an easier way to achieve this. We should provide guidance on how folks should create the audio header.

# This is a raw header based on the spec at https://docs.fileformat.com/audio/wav/
header = b'RIFF\x00\x00\x00\x00WAVEfmt \x10\x00\x00\x00\x01\x00\x01\x00\xc0]\x00\x00\x80\xbb\x00\x00\x02\x00\x10\x00data\x00\x00\x00\x00'

total_length = 0

with open(f"output.wav", "wb") as out:
    out.write(header)
    for response in streaming_responses:
        # calculate the length of the content
        total_length += len(response.audio_content)
        out.write(response.audio_content)
    # Position 40 - 43: Size of the data section
    out.seek(40)
    out.write(bytes([total_length & 0xFF, (total_length >> 8) & 0xFF, (total_length >> 16) & 0xFF, (total_length >> 24) & 0xFF]))

import os
file_size = os.path.getsize("output.wav")

with open(f"output.wav", "r+b") as out:
    # Position 4-7: Size of the overall file - 8 bytes, in bytes (32-bit integer). Typically, you’d fill this in after creation.
    out.seek(4)
    out.write(bytes([file_size & 0xFF, (file_size >> 8) & 0xFF, (file_size >> 16) & 0xFF, (total_length >> 24) & 0xFF]))