CueTools 2.2.6: invalid partition order decoding FLAC with cuetools decoder but not libFLAC

[T-3B]

I was using the default decoder for FLAC in CueTools (that is CueTool's decoder).

When verifying an album CUE sheet (to search matches with CTDB and AR), I came across an error at the track 7: "invalid partition order".
CueTools then stopped there, not showing any result.

Then I went to "Settings" -> "Formats" -> "FLAC" and selected libFLAC as the decoder. CueTools now managed to verify the entire album without any error.

flac -t *.flac reported no error, so there is a problem with CueTools' "native" FLAC decoder.

Here is the 7th track of the album (I think it is enough, but ask me if you want the entire album and/or CUE + LOG): https://pixeldrain.com/u/dSNNc5oB

[c72578]

@T-3B Thanks for your report.
However, the issue could not be reproduced using the "cuetools" flac decoder and "07 - Endless History.flac".

• The test was carried out using an .m3u file for the track:
  issue_359_m3u.zip
• Result for verifying or decoding "07 - Endless History.flac":

[CUETools log; Date: 19.03.2025 06:59:47; Version: 2.2.6]
[CTDB TOCID: 4pj0PTvNcxWVqJXsT5UTXtBmF0k-] found.
Track Peak [ CRC32  ] [W/O NULL] 
 --   98.7 [A57E6F51] [B5CC2E00]           
 01   98.7 [A57E6F51] [B5CC2E00] 

• Under Advanced Settings, cuetools was selected as decoder (default):
  

• It looks like just the single track "07 - Endless History.flac" is not enough to reproduce the issue.

[T-3B]

@c72578 Thanks for your answer.

And sorry to not have shared the wrong file.
By using the same idea as you (with the .m3u file), I can say without any doubt that the problem happens during 6th track decoding.

By changing the name in the .m3u file to use this 6th track: https://pixeldrain.com/u/tBpHg2Ts
I know get: issue_359.m3u: invalid partition order..

(I deleted the link to the 7th track from my preview message, as it was not relevant.)

[c72578]

Thanks for providing the flac file, which causes invalid partition order.
In fact, this flac files contains partition_order=9 multiple times, whereas a maximum of 8 is allowed using the cuetools flac decoder:

cuetools.net/CUETools.Codecs.Flake/AudioDecoder.cs

Line 375 in 7f48316

if (frame.subframes[ch].best.rc.porder > 8)

See attached analysis file from running:
flac.exe -a "06 - TENSION.flac"
06 - TENSION_analysis.zip

So, in this case libFLAC is supposed to be used for decoding the file.

Free Lossless Audio Codec (FLAC), RFC 9639 says for the FLAC streamable subset:

7.  Streamable Subset
...
The Rice partition order (see Section 9.2.7) MUST be less than or equal to 8.

https://datatracker.ietf.org/doc/rfc9639/

[T-3B]

Thanks for the explanation!

I really did not know that CUETools' FLAC decoder was limited to the subset spec (and there were no hint I could find on the GUI for that).

I always thought subset mode was only useful for HW decode on some devices, first time I see it in SW.

Anyway, if supporting non-subset FLAC in CUETools' FLAC decoder is not wanted, feel free to close this issue.
Thanks for your time and help.