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Why checksum uncompressed audio?
_mē_
post Oct 25 2009, 08:06
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FLAC and Wavpack (likely others too) use error detection codes for uncompressed audio data.
Why not for compressed?

I could find only 2 differences:
-you have to decompress the data to verify correctness, which (sometimes greatly) reduces verification performance
-you have more data to be checksumed, which slightly reduces compression / verification performance

What am I missing?
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stigc
post Oct 25 2009, 09:12
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The checksum is meant to proof that the decoded data is the same as the source (e.g. wav file). A checksum of the encoded data will only proof that the file hasn't changed. Off course you could have booth.
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_mē_
post Oct 25 2009, 16:53
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QUOTE (stigc @ Oct 25 2009, 09:12) *
The checksum is meant to proof that the decoded data is the same as the source (e.g. wav file). A checksum of the encoded data will only proof that the file hasn't changed. Off course you could have booth.


AFAIK (not very far) neither FLAC nor WavPack store checksums of the whole audio, but separate ones for each block.
Therefore they aren't useful for comparisons with the source.
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