How should .WAV data be presented to converter?

Paul Singh

Hi,

For sound data recorded in .WAV format, after the header there will all be raw actual data. There storage format is signed. For example, if data depth is 16-bit, the positive value can get up to 2^15-1, and the negative value can get down to -2^15.

Should these data be presented to the converter in its raw format, or does it need any transformation? In addition, is there any MSB/LSB consideration (datasheets say all formats should be MSB first)?

Paul

over 13 years ago

0 Patrick Galvin over 13 years ago

TI__Genius 16270 points

Paul,

If .wav to I2S/analog conversion is being attempted, sending data straight to the converter is not a viable solution as far as I'm aware. Please see this post for reference and more details (http://e2e.ti.com/support/applications/audio/f/22/t/573.aspx).

0 Paul Singh over 13 years ago in reply to Patrick Galvin

Expert 2750 points

Patrick,

Sorry for the delay. I tested and found that .wav file stored in PCM format can directly be used to as I2S stream:

1. In saving options of sound recording software, select PCM. After file header all remaining would be binary signed data (e.g. signed short for bit depth 16).

2. Extract the raw data in MATLAB and save directly into another file.

The only caveat is that in I2S format data MSB for each frame comes at the second bit clock rising edge after frame clock, which needs to be converted in DAC.

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How should .WAV data be presented to converter?