readframes return 2 byte in python

Question

When readframes() is used in python, the online documention says sampling frequency is returned it looks it returns 2 bytes. I think there are 4 byte on each frame:

left = 2 bytes
right = 2 bytes

Do I have to check if it is mono or stereo and if it is stereo, read 2 frames at a time and if it is mono, read 1 frame at a time?

I think you'll have to provide more detail, such as what library are you using? what exact wav format is it? — Keith, May 27 '11 at 08:25
@kim taeyun pydoc.org is hopelessly outdated in favor of http://docs.python.org/ . I updated your link to the latter; I hope you don't mind. — phihag, May 27 '11 at 08:35
What is the Bits per sample resolution of the signal? If it's 16 bps, you'll get two bytes per frame. — Zaur Nasibov, May 27 '11 at 08:35

score 5 · Accepted Answer · answered May 28 '11 at 10:44

A wave file has:

sample rate of Wave_read.getframerate() per second (e.g 44100 if from an audio CD).
sample width of Wave_read.getsampwidth() bytes (i.e 1 for 8-bit samples, 2 for 16-bit samples)
Wave_read.getnchannels() channels (typically 1 for mono, 2 for stereo)

Every time you do a Wave_read.getframes(N), you get N * sample_width * n_channels bytes.

So, if you read 2048 frames from a 44100Hz, 16-bit stereo file, you get 8192 bytes as a result.

readframes return 2 byte in python

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