How to transcode/convert existing Flacs to 16bit / 44100Hz while importing?

[piedrok]

Hi!

In my collection I have some huge Flac files with different frequencies and sample rates.

Now I'd like to convert (or transcode) these to 16bit / 44100Hz Flac files.

The command:

ffmpeg -i $source -y -sample_fmt s16 -ar 44100 -dither_method triangular $dest

does the job.

But while the "beet convert" doesn't convert Flacs to Flacs... instead (so it says in the docs) it just copies the file.

How can I change this behaviour to not ignore existing Flac files while importing?

Ideally only ignoring Flac files that already are in the 16bit / 44100Hz fomat...

Thanks for reading and maybe some help!
Cheers, p.

[Serene-Arc]

The convert plugin does exactly what you're asking! I'm not sure which part of the docs you read but you can definitely convert FLACs and use your own custom ffmpeg command. Here's an example configuration for the plugin.

convert:
  format: flac
  max_bitrate: ????
  formats:
    flac:
      command: ffmpeg -i $source -y -sample_fmt s16 -ar 44100 -dither_method triangular $dest
      extension: flac

The operative option here is max_bitrate. Copying directly from the docs:

max_bitrate: By default, the plugin does not transcode files that are already in the destination format. This option instead also transcodes files with high bitrates, even if they are already in the same format as the output. Note that this does not guarantee that all converted files will have a lower bitrate—that depends on the encoder and its configuration. Default: none.

So set this to a number that you don't want songs to go above, and it will convert everything that goes above it with the given FLAC command. You can also run the FLAC command manually but this should do it automatically.

As always, test this on a test library and group of files to make sure that it won't ruin your music and behaves how you'd like.

[piedrok]

Thanks for your explanation!

I already set up the convert plugin in that way - but I do not know about the bitrate ...

Maybe I got the wrong vocabulary here (not an native speaker!).

How can I force the conversion of files with a sample rate of 48000Hz to 44100Hz with an encoding depth of only 16bit?

Isn't their a similar option for this as "max_bitrate"?

Or am I missing something here?

Thx, p.

[RollingStar]

Be cautious. To reduce the chance of artifacts, people recommend downsampling to a common factor.

192 kHz or 96 kHz converts to 48 kHz
176.4 kHz or 88.2 kHz converts to 44.1 kHz

SoX allegedly does not produce artifacts. I don't know if ffmpeg produces artifacts. https://sourceforge.net/projects/sox/

[piedrok]

Thank you very much for your explanations !

Now I will search my tracks for the different bitrates and have a look at their bit rates. If they seem to have way too big file sizes for my taste I might transcode them... - if not I leave them in place.

Cheers!

[Serene-Arc]

You can use beet info from the info plugin to display all of the information for a track, or list just the bitrates for a query with beet info -i bitrate. Enjoy!

[piedrok]

Hi once more!

The bitrate info query proved really useful - thx again.

But I cannot figure out - sorry to bother you again - how to filter the results to only show all files with a bitrate above 1280 kb (just an example...)... is there a way to do that?

Basically instead of listing thousands of bitrates for individual tracks I'd like to get a short list of only those tracks that exceed my tolerated maximum bitrate...

My workaround would be to re-encode my whole library with the max_bitrate setting you suggested (see above). In theory every file already in the correct (well, my chosen...) format should be omitted and only the higher than max bitrate files would be re-encoded as batch.

But I rather get a list first to check if that's really the way to go...

Do you have any idea how to filter the info output in that way?

Thank you for reading!
Cheers, p.

[RollingStar]

Seems like you should use beet list + custom list output. there should be docs about it.

beet list bitrate:1200.. to get all files with a bitrate above 1200. You can pass them into the convert command as well, and it'll convert them all to your desired format.

The .. is a greater than or less than query. The format could have the name and bitrate, or whatever fields you need.

[piedrok]

Thank you so very much!

The formats from the docs seem to be a bit unintuitive - well, but it'll do... - also good that these commands can be combined - I'll figure it out... :-) - it's exactly what I've been looking for!

Thx again, best regards,
pk