[HELP] Converting from FLAC to ALAC resulting in noisy file

[Eraser 66]

Hi everyone,

 

I'd like to ask for your help, because I'm out of ideas right now. I've been building my music library for a lot of years, always aiming for good quality rips. 320kbps mp3 and 256kbps VBR AAC are good enough for me, so I'm usually not looking for lossless. However, there are some albums that can't be find in good quality mp3 or AAC - it's either FLAC or a bad transcode. In these cases, I usually download the FLAC files, convert them to ALAC (because FLAC is not supported by iTunes) with a tool called "Bigasoft Audio Converter", put the ALAC files in iTunes, then convert them to AAC. I thought this method was safe to use, because I've been told there's no quality loss when converting from lossless to lossless.

 

Today I've been listening to a 12012 album ("mar maroon") I previously converted from FLAC to ALAC then AAC, and suddenly realised there was some kind of noise at the beginning of track 2 ("DNA") that shouldn't have been there. At first, I thought the original FLAC file was corrupted, but when I opened it, I couldn't hear any noise. Made another ALAC file, and it was there again. Then I downloaded another tool ("Mediahuman Audio Converter") hoping for a different result, but it gave me the same noisy ALAC file. Even made a WAC conversion, and that couldn't help either.

 

My question is: do you think there's some kind of problem with this specific FLAC file, or it's something else? I'm worried that the method I've been using for years isn't as safe as I thought. The noise itself isn't that bad, but I really don't want to look through my whole library just to realize other files have the same (or worse) problem. If it helps, the FLAC file I'm talking about was previously uploaded here at MH by mucc6 (who was generous enough to share almost the whole 12012 discography in lossless - thanks a lot for that!), and I believe the same rip can be find at JPopsuki. Anyway, I've uploaded this specific track in FLAC and ALAC for those who are willing to check it:

 

http://www.mediafire.com/file/u6aiuu6bec4jdeb/DNA.rar

 

It's right at 0:00 in the ALAC file. Maybe you won't notice it at first, but I believe it can easily be heard if you listen closely.

 

Any help would be much appreciated! Thanks everyone, and sorry for the long post. 

[Zeus 7997]

I hear no difference between the FLAC and the ALAC. I listened using fb2k on Win 10.

[d4rkie 5]

Quote

 

All tracks decoded fine, no differences found.

Comparing:
"\DNA\ALAC.m4a"
"\DNA\FLAC.flac"
Compared 11249028 samples.
No differences in decoded data found.

 

 

the data is the same

 

Edit: Might be an iTunes' decoder bug - try with some other app (on mac, vox http://coppertino.com ; on windows - foobar2000) and see if the noise persists.

[Eraser 66]

Thanks for the replies! I've tried foobar2000 - it's still there, but only when I manually open the file (file --> open). If it's in the player and I click "play", it sounds flawless.

 

This is very strange. I previously tried iTunes, Media Player Classic Home Cinema and my iPod Classic, it was there each time. Since it sounds the same on my iPod, I don't think the problem is with my PC or speakers, but I'm gonna try it on a different computer later to see if I hear any difference.

 

Anyway, I'm releaved there's nothing wrong with the conversion process I've been using. I can live with this if it's just this one particular song or album, but if anyone has any idea what can be behind this, please share them. Thanks again for your help!

[Rekonixir 0]

hi,

i don't know whether you still need the answer,  i used Bigasoft Audio Converter   too but in fact, this program  extract audio is not good. When I upgraded, whenever I converted FLAC to ALAC, it would prompt me to fail to switch, I consulted their logistics department, but could not give me a definite solution, and then I used another converter,http://www.videoconverterfactory.com/tips/flac-to-alac.html the fact Proved that it really can finish FLAC conversion success and as long as not to change the bit rate, the sound quality will not be damaged

[Eraser 66]

Hello,

 

thanks for your comment, but I believe we have a different problem here. Someone already confirmed it back then that the ALAC and FLAC files I linked here had the same data, which means my problem wasn't caused by Bigasoft Audio Converter. I still didn't manage to solve it though, but at least none of my other files/albums seems to be affected by this.

I will look into Bigasoft Audio Converter a bit more after hearing what happened to you, but I really don't think it's the source of my problem. Anyway, thanks again for sharing this, and I'm glad you could find another software that works for you.

[Laurence02 185]

I use xrecode II and am happy with it.

[Zeus 7997]

On 11/18/2016 at 7:41 PM, Eraser said:

Hi everyone,

 

I'd like to ask for your help, because I'm out of ideas right now. I've been building my music library for a lot of years, always aiming for good quality rips. 320kbps mp3 and 256kbps VBR AAC are good enough for me, so I'm usually not looking for lossless. However, there are some albums that can't be find in good quality mp3 or AAC - it's either FLAC or a bad transcode. In these cases, I usually download the FLAC files, convert them to ALAC (because FLAC is not supported by iTunes) with a tool called "Bigasoft Audio Converter", put the ALAC files in iTunes, then convert them to AAC. I thought this method was safe to use, because I've been told there's no quality loss when converting from lossless to lossless.

 

Today I've been listening to a 12012 album ("mar maroon") I previously converted from FLAC to ALAC then AAC, and suddenly realised there was some kind of noise at the beginning of track 2 ("DNA") that shouldn't have been there. At first, I thought the original FLAC file was corrupted, but when I opened it, I couldn't hear any noise. Made another ALAC file, and it was there again. Then I downloaded another tool ("Mediahuman Audio Converter") hoping for a different result, but it gave me the same noisy ALAC file. Even made a WAC conversion, and that couldn't help either.

 

My question is: do you think there's some kind of problem with this specific FLAC file, or it's something else? I'm worried that the method I've been using for years isn't as safe as I thought. The noise itself isn't that bad, but I really don't want to look through my whole library just to realize other files have the same (or worse) problem. If it helps, the FLAC file I'm talking about was previously uploaded here at MH by mucc6 (who was generous enough to share almost the whole 12012 discography in lossless - thanks a lot for that!), and I believe the same rip can be find at JPopsuki. Anyway, I've uploaded this specific track in FLAC and ALAC for those who are willing to check it:

 

http://www.mediafire.com/file/u6aiuu6bec4jdeb/DNA.rar

 

It's right at 0:00 in the ALAC file. Maybe you won't notice it at first, but I believe it can easily be heard if you listen closely.

 

Any help would be much appreciated! Thanks everyone, and sorry for the long post. 

Okay, I thought of something you could try. If you have that exact file for DNA, can you cut the first five seconds of the FLAC and ALAC, convert again using the same converter from before, and compare? I think you may have found some weird edge case in the program that should be looked into more.

Also I ask for the first five seconds and not the whole thing because I want to isolate the total number of bits that could affect it.

[Eraser 66]

Hi, thanks for the tip! After reading your post, I listened those two files I linked in my OP once again, and I noticed I could hear that "noisy" part (really don't know how to describe it properly, sorry) not only in the ALAC file, but the FLAC file as well. Since I wasn't 100% sure it was the original FLAC file, I downloaded DNA.flac from JPopsuki once again, and I could still hear it.

 

When I opened this thread, I believe I was on a different system (although I was using the same speakers), so that might explain this somehow, even though I still don't really understand why I can only hear it in one file on a specific system, but hear it in both on another, while others can't hear it at all. Anyway, I think it's safe to assume the converter doesn't have anything to do with it, since there was no conversion at all on my part this time.

 

I don't know if you still want me to cut those 5 seconds. If you do, I'll gladly do that, just please confirm it if this is what you meant, because I'm not sure I understood you right. So first I should find those two files (FLAC and ALAC) I was referring to when I created this thread, save the first 5 second of the FLAC file in FLAC & save the first 5 second of the ALAC file in ALAC, then upload them here? I don't know how to do the comparision, so if you could help me with that, that would be much appreciated. Even though this particular problem was most likely caused by something else than Bigasoft Audio Converter, Rekonixir's post suggested this program has same issues that should be looked into.

 

[Zeus 7997]

If it's in both there's no need for all that work now, since we know where it comes from! The sound chip or onboard DAC between the two systems may be the culprit. The one where you can hear it must be of a higher quality or something.