Demucs + CentreCutCL - Stereo-to-5.1 Script v 0.2b


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That's good news... at least we know it gets most of the way through. Attached is a version of the "PrepForDemucs.bat" with Echo turned off and a few 'pause' commands which will hopefully identify which command is failing. It is saved as a txt file as 'bat' files cannot be attached on the forum - just save it to the script folder and rename it to "PrepForDemucs(Debug).bat". Run as normal and there should be a lot more text in the command console. It will ask you to "press any key" at each pause. Please can you let me know if/where it stops or if the cmd window closes. I suspect it will be one of the FOR or IF commands, as these can cause the console window to close unexpectedly.
The first pause is here :

The second is here :


Then the cmd window closes....
Damn! I thought I'd fixed it. The pauses are just in there temporarily so that I can see what's going on. Would you mind sending me a screen grab of the first pause again with the updated script from my last post?
It seems the 'Dir' command output varies in different languages... I found another way of getting the filesize though - try the attached as before. I've put a pause in just after the new command so that we can see if it works.


  • PrepForDemucs(Debug).txt
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It seems the 'Dir' command output varies in different languages... I found another way of getting the filesize though - try the attached as before. I've put a pause in just after the new command so that we can see if it works.

It's working now. Thanks.:)
New version 0.2e

Available here: Demucs+CC_Stereo_to_5.1v0.2e

Bug fixes as follows:
  • Fixed issue causing 'PrepForDemucs.bat' to fail in languages other than English
  • Fixed issue causing 'PostDemucs.bat' to fail when converting 10 or more files
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Hi Nnickspoiler,

I was chatting with Zeerounder about trying to work out what might be going wrong on your setup. Perhaps it is a language issue - I believe you are in France? It might be that some of the commands or the output from certain parts of the script (eg date/time etc) are different and therefore causing it to fail. Another possibility might be 'illegal' characters in the path to where either the source file or the script is saved. Perhaps you could try with both in the route directory of your harddrive? If you could give me some more info I might be able to solve the problem and if necessary tweak the script.

Below are some step-by-step instructions I sent Nikomen. By following these he did manage to get up and running and has successfully completed a few conversions - maybe they will help you too.

1) Drag your source file onto the "PrepForDemucs.bat" The following dialogue should pop up:


2) Click yes for desktop, no to choose another folder. If you click 'no' - you should see the following:


3) Browse to your desired destination ( In the above, I chose my "E" drive and clicked "make new folder" - called it PurpleRain) - then click "ok"

4) The Command window should look something like this while it prepares the files:


5) When complete, you should get this box, and the two web pages will open in your default browser:


6) Click ok to close the above dialogue box and go to the browser

7) On MVSEP, Click "Add Audio File" and browse to the "ForDemucs" folder. For larger files, the prep script will have split the file into chunks of less than 100MB due to MVSEP file size limit (as per below).


8) Choose the options options below and click Separate. If there are multiple parts, or you have prepared more than one file, convert all files in the "ForDemucs" folder with the same settings.


9) Once separation is complete, download Drums/Bass/Other and Vocals and save/move to the "Demucs" Folder


10) The "Demucs" Folder should now look something like the example below (In this case, I have 8 files as the source file was split in to two parts):


11) Now double click on the "PostDemucs.bat" Script and you should see the dialogue box as below. The screen shot is from a previous version of the script, it will continue after 5 seconds, or you can click 'ok':


12) Another dialogue as below. Click yes to accept defaults, or no to choose other options & follow the prompts


13) The command prompt will look like this for a few minutes...


...and then...

14) Click ok (or just wait 30 seconds)


15) More Command prompt processing... After a few minutes you should get a confirmation pop-up that all is finished:


16) Once complete, your conversion folder should look something like this, with the 'final' flac file in a folder called "Final_[bass_4.0,drums_4.0,piano_4.0,vocals_5.0,other_5.0]" - the selected options will be in the [brackets]:

17) And here is the result:


I hope you can get it working!
None of the images in the quoted post seem to be displaying anymore.

The popup recommends Demucs3 Model B (vocal, bass, drums, other) . There is now a Demucs4 HT (vocal bass drums other) on offer at Is Demucs3 still recommended?
None of the images in the quoted post seem to be displaying anymore.

The popup recommends Demucs3 Model B (vocal, bass, drums, other) . There is now a Demucs4 HT (vocal bass drums other) on offer at Is Demucs3 still recommended?
It should work with the mvsep demucs4 output. I've been super busy for the last few months, so haven't had much spare time to test out the new models, but I believe they should give better/cleaner results
I'm using Demucs+CC_Stereo_to_5.1v0.2e but not having success, on Windows 10. The hangup is in the PostDemucs.bat process. The input is 8 files output by (two sets of vocal/bass/drums/other files, because there were two _split files generated by PrepforDemucs.bat) and placed in the \Demucs folder. The PostDemucs process ostensibly hangs at "Measuring loudness of combined Mch mixdown..' step. But there are two prior SoX fails, probably crucial. There is an audio file in \Source_-6dB . There are no audio files in \Stems and its subdirectories. And thus no files in \Mch_Mixdown_[bass_4.0,drums_4.0,piano_4.0,vocals_5.0,other_5.0] either. So nothing to measure.

I tried both Demucs3 and Demucs4 modes in mvsep, both have the same issue with PostDemucs.bat.

All Stems for "Sound_Chaser_HDCD" Done Input File : 'Source_-6dB\FileNo_1_-6dB.flac' Channels : 2 Sample Rate : 44100 Precision : 24-bit Duration : 00:09:29.07 = 25095840 samples = 42680 CDDA sectors File Size : 111M Bit Rate : 1.55M Sample Encoding: 24-bit FLAC Comment : 'encoder=Lavf58.29.100' In:100% 00:09:29.07 [00:00:00.00] Out:25.1M [ | ] Clip:0 Done. Sox: SoX v14.4.2 Sox FAIL sox: Not enough input filenames specified Usage summary: [gopts] [[fopts] infile]... [fopts] outfile [effect [effopt]]... SPECIAL FILENAMES (infile, outfile): - Pipe/redirect input/output (stdin/stdout); may need -t -d, --default-device Use the default audio device (where available) -n, --null Use the `null' file handler; e.g. with synth effect -p, --sox-pipe Alias for `-t sox -' SPECIAL FILENAMES (infile only): "|program [options] ..." Pipe input from external program (where supported) http://server/file Use the given URL as input file (where supported) GLOBAL OPTIONS (gopts) (can be specified at any point before the first effect): --buffer BYTES Set the size of all processing buffers (default 8192) --clobber Don't prompt to overwrite output file (default) --combine concatenate Concatenate all input files (default for sox, rec) --combine sequence Sequence all input files (default for play) -D, --no-dither Don't dither automatically --dft-min NUM Minimum size (log2) for DFT processing (default 10) --effects-file FILENAME File containing effects and options -G, --guard Use temporary files to guard against clipping -h, --help Display version number and usage information --help-effect NAME Show usage of effect NAME, or NAME=all for all --help-format NAME Show info on format NAME, or NAME=all for all --i, --info Behave as soxi(1) --input-buffer BYTES Override the input buffer size (default: as --buffer) --no-clobber Prompt to overwrite output file -m, --combine mix Mix multiple input files (instead of concatenating) --combine mix-power Mix to equal power (instead of concatenating) -M, --combine merge Merge multiple input files (instead of concatenating) --multi-threaded Enable parallel effects channels processing --norm Guard (see --guard) & normalise --play-rate-arg ARG Default `rate' argument for auto-resample with `play' --plot gnuplot|octave Generate script to plot response of filter effect -q, --no-show-progress Run in quiet mode; opposite of -S --replay-gain track|album|off Default: off (sox, rec), track (play) -R Use default random numbers (same on each run of SoX) -S, --show-progress Display progress while processing audio data --single-threaded Disable parallel effects channels processing --temp DIRECTORY Specify the directory to use for temporary files -T, --combine multiply Multiply samples of corresponding channels from all input files (instead of concatenating) --version Display version number of SoX and exit -V[LEVEL] Increment or set verbosity level (default 2); levels: 1: failure messages 2: warnings 3: details of processing 4-6: increasing levels of debug messages FORMAT OPTIONS (fopts): Input file format options need only be supplied for files that are headerless. Output files will have the same format as the input file where possible and not overridden by any of various means including providing output format options. -v|--volume FACTOR Input file volume adjustment factor (real number) --ignore-length Ignore input file length given in header; read to EOF -t|--type FILETYPE File type of audio -e|--encoding ENCODING Set encoding (ENCODING may be one of signed-integer, unsigned-integer, floating-point, mu-law, a-law, ima-adpcm, ms-adpcm, gsm-full-rate) -b|--bits BITS Encoded sample size in bits -N|--reverse-nibbles Encoded nibble-order -X|--reverse-bits Encoded bit-order --endian little|big|swap Encoded byte-order; swap means opposite to default -L/-B/-x Short options for the above -c|--channels CHANNELS Number of channels of audio data; e.g. 2 = stereo -r|--rate RATE Sample rate of audio -C|--compression FACTOR Compression factor for output format --add-comment TEXT Append output file comment --comment TEXT Specify comment text for the output file --comment-file FILENAME File containing comment text for the output file --no-glob Don't `glob' wildcard match the following filename AUDIO FILE FORMATS: 8svx aif aifc aiff aiffc al amb amr-nb amr-wb anb au avr awb cdda cdr cvs cvsd cvu dat dvms f32 f4 f64 f8 flac fssd gsm gsrt hcom htk ima ircam la lpc lpc10 lu maud mp2 mp3 nist ogg prc raw s1 s16 s2 s24 s3 s32 s4 s8 sb sf sl sln smp snd sndr sndt sou sox sph sw txw u1 u16 u2 u24 u3 u32 u4 u8 ub ul uw vms voc vorbis vox wav wavpcm wv wve xa PLAYLIST FORMATS: m3u pls AUDIO DEVICE DRIVERS: waveaudio EFFECTS: allpass band bandpass bandreject bass bend biquad chorus channels compand contrast dcshift deemph delay dither divide+ downsample earwax echo echos equalizer fade fir firfit+ flanger gain highpass hilbert input# ladspa loudness lowpass mcompand noiseprof noisered norm oops output# overdrive pad phaser pitch rate remix repeat reverb reverse riaa silence sinc spectrogram speed splice stat stats stretch swap synth tempo treble tremolo trim upsample vad vol * Deprecated effect + Experimental effect # LibSoX-only effect EFFECT OPTIONS (effopts): effect dependent; see --help-effect Combining Mixdown files for loudness measuring... Sox FAIL formats: can't open input file `Mch_Mixdown_[bass_4.0,drums_4.0,piano_4.0,vocals_5.0,other_5.0]\FileNo_1_[bass_4.0,drums_4.0,piano_4.0,vocals_5.0,other_5.0].wav': No such file or directory Measuring loudness of combined stereo source files... Loudness -12.98 LUFS Range +11.50 LU Peak -0.53 dB Measuring loudness of combined Mch mixdown...
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