Flac Re-encoding Level Errors?

[ikrananka]

I have just completed re-encoding my entire Flac collection using dMC. The previous tracks were ripped using a mixture of EAC and dBpoweramp, various versions of flac and various compression levels. My main reason for re-encoding was to get consistency across my music library and to use the time to also sort out a large number of tagging inconsistencies and compatibilities.

All went well but was very time consuming. However, I am now concerned that I have somehow corrupted my flac files. When listening to some tracks I hear the track volume drift up and down when it didn't do that before the re-encoding. This has occurred when listening on both my PC and my Sonos system. I intend to make a list of tracks where this is obvious but I am concerned that in some way all of my rips have become corrupted and are no longer accurate.

Is there any way I can know for certain? Has anyone else has experienced this? Is there a solution?

Appreciate any help.

[Spoon]

Re: Flac Re-encoding Level Errors?

Unless you added a DSP effect such as volume normalize, the flac files will be identical to the original.

[ikrananka]

Re: Flac Re-encoding Level Errors?

I didn't apply ANY normalize DSP effect. The only DSP I used was ID Tag Processing.

When re-encoding I increased the flac compression level from 5 to 8 - not that this should have any apparent influence on playback.

The odd thing though is that the volume clearly fluctuates. I'll need to start logging on what tracks this happens and then check if it is repeatable and is the same across devices.

What would be nice is to have a utility to run through my flac files and compare against AccurateRip again - just to ensure that my flac files still are accurate.

[Tigerman]

Re: Flac Re-encoding Level Errors?

Rip a few songs, that have that fluctuation, again and use the audio crc to compare the audiocontent.
(Obvisously you have to use the same offset settings while ripping )

[Benji99]

Re: Flac Re-encoding Level Errors?

I've just done the same thing as the Topic starter.
My flac files were also encoded at various compression levels via various encoders.

I didn't experience any sound issues and had only the following issues:

- Tons of "md5 did not match decoded data, file is corrupt." errors which seemingly didn't mean any audible problems. (If there was, I couldn't hear the problem from the files I tested)
- The files tagged as such sounded fine by dBmc failed to copy ANY tags to the files.
- Several files had other errors and all those errors turned out to be correct. Those files were indeed corrupt and Foobar complained about them too.
- My Custom tags got partially destroyed because the current flac codec doesn't seem to handle multi-value custom tags (it only successfully copies the first occurence of the tag)

[Spoon]

Re: Flac Re-encoding Level Errors?

>- Tons of "md5 did not match decoded data, file is corrupt." errors which seemingly didn't mean any audible problems

Those files had errors 100% for sure, just because the file could decode does not mean it was 100% identical to the compressed file. Each time flac is encoded it self stores an md5 of the source audio, programs like foobar might not compare that to tell a file is corrupted.