Fingerprint result with force fpcalc is other than with default settings

[garlontas]

Hello!
I'm developing an application using your library and I had the problem that I didn't get any result with the default fingerprinting. (acoustid.match(self.__API_KEY, self.__file)) 😞
Then I used acoustid.match(self.__API_KEY, self.__file, force_fpcalc=True) and I received the data I needed. 👍
Maybe you could take a look at this problem.
A possible solution would be setting fpcalc as the default finger printer.

PS: It also occurs using your aidmatch.py script

[sampsyo]

Is there a way you can describe to reproduce the problem?

[garlontas]

So first I had this code:

        try:
            results = acoustid.match(self.__API_KEY, self.__file)
        except acoustid.NoBackendError:
            raise error.ChromaprintNotFoundException(
                "Chromaprint library/tool not found")
        except acoustid.FingerprintGenerationError:
            raise error.FingerprintGenerationError(
                "Fingerprint could not be calculated")
        except acoustid.WebServiceError as exc:
            raise error.WebServiceError("Web service request failed:", exc.message)
        try:
            result = next(results)
        except StopIteration as exc:
            raise error.FingerprintGenerationError(
                "Fingerprint could not be calculated") from exc
        self.__id = result[1]
        return self.__id

When I run that code, your pyacoustid calculates the fingerprint with the default calculator, and it fails with the StopIteration error because the generator is empty.

Afterwards I changed the code and wrote this:

        try:
            results = acoustid.match(self.__API_KEY, self.__file, force_fpcalc=True)
        except acoustid.NoBackendError:
            raise error.ChromaprintNotFoundException(
                "Chromaprint library/tool not found")
        except acoustid.FingerprintGenerationError:
            raise error.FingerprintGenerationError(
                "Fingerprint could not be calculated")
        except acoustid.WebServiceError as exc:
            raise error.WebServiceError("Web service request failed:", exc.message)
        try:
            result = next(results)
        except StopIteration as exc:
            raise error.FingerprintGenerationError(
                "Fingerprint could not be calculated") from exc
        self.__id = result[1]
        return self.__id

Now everything worked, and I got no errors (fpcalc version 1.4.3)

The file I tested with has the fpcalc result:
result.txt

[swanux]

I can confirm this issue, I have the exact same problem.

OS: elementaryOS 6 (Ubuntu 20.04)
chromaprint: 1.4.3 (distribution provided)

[robbat2]

@garlontas I just ran into this as well.

I was trying to dedupe my personal music collection, and I have two rips of specific song from a CD; one as FLAC, another as MP3.

force_fpcalc=True and I get 99% similarity between the MP3 & FLAC.
force_fpcalc=False and I get 0.0% similarity between the MP3 & FLAC.

Specifically, the MP3's fingerprint between the two methods, even with maxlength 3

[RenaKunisaki]

This might be the same issue I noticed. I transcoded an MP3 to FLAC for testing, and the fingerprints differ at the end, even though the waveforms appear to be identical.