Question about flac and other lossless codecs

[drspy00]

This may be a stupid question but I have just converted all my ape files into flac files because flac has better support for what i need it for but I was wondering, is there a way to verify that the files converted to flac properly?

When something is converted to flac is the conversion verified to make sure it is a bit for bit copy of the original wav file within the original ape file.

if anyone knows of another way to verify this it would be great because I don't want to delete the original ape files until I know for sure they were converted as flac files perfectly.

[LtData]

Re: Question about flac and other lossless codecs

This is an option in dMC r12, currently in beta. It is called "After Encoding Verify Written Audio" and ensures that the original was copied to the new file successfully.

[drspy00]

Re: Question about flac and other lossless codecs

That sounds good, I'm looking forward to the new version if it has features like that. I wouldn't have thought dmc could have got any better.

[drspy00]

Re: Question about flac and other lossless codecs

Has anyone ever known a file not to copy properly from lossless to lossless?

[LtData]

Re: Question about flac and other lossless codecs

Not in my experience, no. I think most errors are encoder errors or, very rarely, hard drive errors while reading/writing the file.

[xoas]

Re: Question about flac and other lossless codecs

I would point out that with r11.5 and earlier there may be circumstances in which a conversion will fail but only after creating a shell file that will give you the impression of a successful conversion unless you check file size (which will be very small, no more than a few kb). This is most likely to occur in batch conversions and I do not believe that lossless to lossless conversions are immune to this type of error. Also, I am not sure whether r12 is immune to this type of error or not.

The answer for this type of error is to check the file size of your converted files to make sure that file size is correct.

With large batch conversions, some files may fail to convert altogether. Since r11.5 and earlier do not generate a log of such failed conversions (I believe I have read that r12 is supposed to have this feature), it would be a good practice with a batch conversion to confirm that you have the correct number of output files.

Best wishes,
Bill

[dizwell]

Re: Question about flac and other lossless codecs

I used to rip to FLAC all the time, and since I have over 11,000 tracks, I got very nervous whether any corruption was being introduced etc., because re-ripping many of them would be a pain in the butt.

Then I found the entirely free FlacTester (at http://www.vuplayer.com/other.php), and all my problems were behind me! If that reports the all-clear, you can pretty much take it as given that your Flac files are 'clean'.

Now... if only there was a similar utility for WMAs!!

[Spoon]

Re: Question about flac and other lossless codecs

You could use R12 which has a verify written audio data, for both wma lossless and FLAC (which will be better than FlacTester as it compares to the orignal data, not relying on FLACs own error checking routines).

[dizwell]

Re: Question about flac and other lossless codecs

They're complementary, I think. Once the track has been ripped, how do you know that it hasn't become corrupted later (perhaps much later). I managed to corrupt about 1000 tracks by forgetting -once- to 'stop' an external USB drive before unplugging it.

So absolutely verify after a rip: but Flactester run once a week (say) against all your files give you that extra bit of comfort.