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Calculating the number of samples in a WAV file

I am currently looking at online examples and here is a WAV file contents in bytes

52 49 46 46 24 08 00 00 57 41 56 45 66 6d 74 20 10 00 00 00 01 00 02 00 22 56 00 00 88 58 01 00 04 00 10 00 64 61 74 61 00 08 00 00 00 00 00 00 24 17 1e f3 3c 13 3c 14 16 f9 18 f9 34 e7 23 a6 3c f2 24 f2 11 ce 1a 0d

and here is the visual; representation:

enter image description here

So according to the Subchunk2Size there is 2048 bytes in the data. The formula to calculate the number of samples in a WAV is given as:

Subchunk2Size /(NumChannels * BitsPerSample/8 ) = NumSamples

If I plugin numbers and according to the information given I get NumSamples = 512. But in the diagram the sample rate is 22050. How can the total number fo samples be less than a single second of samples?

Solution

  • For those wondering, here is a link to the source.

    I suspect they are just using a bad example where the duration of the wav file would be less than a second. Their formula makes sense and we can use it to verify the data size of a one second wav file.

    If our sample rate is 22050 samples/sec and our wav file is one second, then numSamples = 22050. We know that Subchunk2Size is the number of bytes in the data and can be calculated using this formula: Subchunk2Size = numSamples * numChannels * bitsPerSample / 8 , so, assuming numChannels = 2 and bitsPerSample = 16, we know that a one second wav file should be (22050 * 2 * 16 / 8) bytes which is 88200 bytes, so it would make sense that if Subchunk2Size is 2048 bytes, as per the website's example, then the duration of the wav file would be less than a second and thus, numSamples would be less than 22050.