How to batch convert ALAC to FLAC on Windows?

[Shaorin]

How do you batch convert ALAC to FLAC without any loss of quality on Windows?

[ProWo]

You can use clever FFmpeg-GUI.
1) Load the first alac file, click encode audio stream, set flac as encoder, click to batch.
2) click Batch tasks, drag all other alac files into and click execute.
Done.

[Shaorin]

You can use clever FFmpeg-GUI.
1) Load the first alac file, click encode audio stream, set flac as encoder, click to batch.
2) click Batch tasks, drag all other alac files into and click execute.
Done.

How do I prevent it from removing the cover art & metadata when remuxed to flac?

[cholla]

Clever may be able to keep cover art & metadata.
I will look into this .

[Shaorin]

I found another tool called freac that does it all. I'm just wondering is it normal for ALAC converted to FLAC be larger than original in size? since all I'm doing is converting with 0 compression

[hello_hello]

FLAC compresses the audio but it's still lossless. The command line option is --compression-level where zero is the fastest option but with larger file sizes (less compression) and --compression-level 8 is the slowest.

I've no idea if freac lets you configure the compression level, but scroll down to the encoding options section here.
https://xiph.org/flac/documentation_tools_flac.html

There's a lossless encoder comparison table here (using the default encoder settings, which would be compression level 5 for flac).
https://wiki.hydrogenaudio.org/index.php?title=Lossless_comparison

Foobar2000 will convert ALAC to FLAC for you. You might also need to download the free encoder pack.
https://www.foobar2000.org/windows
https://www.foobar2000.org/encoderpack

Edit: Foobar2000 can definitely be configured to copy the metadata, which I "think" includes album/cover art (I never add cover art to files myself).
It's not the latest version, but I uploaded a portable version of foobar2000 aimed at audio encoding here if you want to try it:
https://forum.videohelp.com/threads/396860-foobar2000-portable-%28for-audio-encoding%29

[ProWo]

You can use clever FFmpeg-GUI.
1) Load the first alac file, click encode audio stream, set flac as encoder, click to batch.
2) click Batch tasks, drag all other alac files into and click execute.
Done.

How do I prevent it from removing the cover art & metadata when remuxed to flac?

To keep the cover art, you must copy it's stream.
After 1) close the app. In your target folder you'll find a BT_open.txt file.
Edit it with a text editor and change this:

 -vn -sn -dn

to

 -map 0:1 -c:v copy -sn -dn

Save the file and restart clever.
Continue with 2)

[cholla]

I was just testing & used .mp3 files.
ProWo's method did not work for me.
I got an error at the end that stated zero byte file generated,etc.

It did work when I did not attempt to add album art but the file order was not the same as what I dragged into Clever.
There was a way to correct this but it is a time consuming process.

Most people want to run a batch script.
I'm not sure that would be possible.
I will see what else is suggested.

foobar was able to convert & tag with cover art.
I only tested it with a single file.
Again it takes some time.

If freac did what the OP wanted then that is good enough.

[ProWo]

I was just testing & used .mp3 files.
ProWo's method did not work for me.
I got an error at the end that stated zero byte file generated,etc.

The method works only, if the audiostream is stream 0 and then coverart is stream 1.
Otherwise, you will have to adjust the maps.

[cholla]

I got it to work on the third try.
I must have answered some of the Messages incorrectly.
This one came up on the first song & then 9 more times when I dragged the rest into the batch list: I was not sure but I answered "Yes".

[Attachment 91173 - Click to enlarge]

Later I also answered this Message "Yes":

[Attachment 91174 - Click to enlarge]

The song names are changed to this:
01 - Sweet Revenge$_A0.flac
Not like the original:
01 - Sweet Revenge

The code is changed from this:

-map 0:0 -c:a flac -ar 44100

To this:

-map 0:0 -c:a flac -ar 44100 -map 0:1 -c:v copy -sn -dn

[ProWo]

I got it to work on the third try.
I must have answered some of the Messages incorrectly.
This one came up on the first song & then 9 more times when I dragged the rest into the batch list: I was not sure but I answered "Yes".

Correct.

Later I also answered this Message "Yes":

This are audio recodes, so there is no need to mux them.
You can answer NO here.

The song names are changed to this:
01 - Sweet Revenge$_A0.flac
Not like the original:
01 - Sweet Revenge

This is by design and ok so.

The code is changed from this:

-map 0:0 -c:a flac -ar 44100

To this:

-map 0:0 -c:a flac -ar 44100 -map 0:1 -c:v copy -sn -dn

Well done.

[ListyDoM]

How do you batch convert ALAC to FLAC without any loss of quality on Windows?

ffmpeg -i input.m4a -c:a flac -vcodec copy output.flac

Batch processing (all files in the folder):

for %i in (*.m4a) do ffmpeg -i "%i" -c:a flac -vcodec copy "%~ni.flac"

[cholla]

@ ListyDoM,
Worked like a charm song titles & cover art.

If the OP wants 16-bit FLAC use this:

for %i in (*.m4a) do ffmpeg -i "%i" -c:a flac -sample_fmt s16 -vcodec copy "%~ni.flac"

@ ProWo,
I just like my song titles named a certain way.
They work better on players this way.
Keeping the correct playing order.
I have a batch renaming software so I can rename several files when I need to.
I will have to test it but I'm not sure my car stereo plays .FLAC