The June development update is overdue, but better late than never, here it is. It was a very productive month, so let's get right to the good stuff.

Parallel conversion jobs

The current alpha release supports only one conversion job at a time. Multiple tracks in a conversion can be processed in parallel, but when you try to start a new job while a conversion is still running, you just get a message asking if you would like to schedule the new job for after the current one is finished.

The next release will enable parallel conversion jobs. As long as there are CPU threads left, multiple conversions, possibly using different settings, can run at the same time. This helps when converting multiple albums to a single file per album or when ripping CDs using multiple drives.

Improved handling of automatic ripping

This brings us to the next item. There are some issues with the current alpha when using the automatic ripping option with multiple drives. When inserting a disc while other tracks are still in the joblist, the new ripping job will try to process those other tracks again, leading to some tracks being ripped more than once. Also, the new job will not start before any currently running rip is finished. Both issues will be fixed in the next alpha which makes ripping with multiple drives much more usable.

Fixed metadata bug with Core Audio on Windows

In May, a user opened an issue on GitHub reporting that when converting ALAC files to AAC using the Core Audio encoder on Windows, tags were missing on some files. I could easily reproduce the issue, but it seemed really strange. It occurred only when converting files decoded with an external decoder (i.e. a separate .exe called by fre:ac) and the selected encoder was Core Audio. That didn't seem to make any sense at first.

It turned out to actually be a bug in Apple's Core Audio implementation on Windows. It would make file handles created by its API calls inheritable by sub-processes. The sub-processes (in this case the external decoders) would then inherit any open handles and lock the respective files, making them unwritable by the tagger component.

Making handles inheritable is something that an API never should do as it can lead to unforeseeable behavior and very difficult to analyze bugs.

Fortunately there is a work-around by avoiding the problematic APIs. The next alpha release will include this fix.

Automatic codec builds

Till now, all the codecs included with fre:ac are built manually: Set the correct compiler flags for each codec on each supported OS, apply necessary patches, configure the codecs with the right flags and run make to build them. This costs a lot of time whenever a new codec version is relased and also is a bit error-prone, so it was necessary to change it.

I built a script to automate all the steps listed above for most of the necessary codecs and some other libraries. The script can compile FAAC, FAAD2, FDK-AAC, FLAC, LAME, libav, libogg, libsamplerate, libsndfile, Monkey's Audio, mpg123, Opus, RubberBand, Speex, Vorbis and WavPack on Windows, macOS, Linux and FreeBSD. Whenever a new version of one of these libraries is released in the future, I can simply update the package download URL and run the script to build a new release.

The script can be found in the source repository on GitHub.

Reworked donation dialog

The donation dialog has been reworked to support more payment types. Previously supporting only PayPal, the new dialog adds support for Donorbox, SEPA transfers and the Bitcoin and Ethereum crypto currencies.

Other items

A number of other changes have been implemented in the past month, the most notable of which are:

• HiDPI icons
  Preparing for the upcoming beta release, I added higher quality versions of the toolbar icons that now look crisp on HiDPI displays like Apple's Retina screens.

• Completely translatable
  In the current alpha release, not all strings are translatable. This applies to configuration dialogs for external codecs especially. The next alpha will fix this and enable translations for WavPack, Musepack, OptimFROG and TAK configuration dialogs along with some other previously untranslatable strings.

• Fixed MP4 metadata bug
  When converting multiple files in parallel to AAC or ALAC output, it can happen that some files end up being unoptimized due to a bug in the MP4v2 library used by fre:ac. Optimization of MP4 files means that tags and the seektable are moved to the beginning of the file for more efficient processing. The next alpha release will include a work-around for the MP4v2 bug fixing the issue of MP4 files not being optimized.

• Downloads now hosted on GitHub
  The links on the downloads page now point to GitHub instead of SourceForge. This enables direct downloads without an intermediate page to choose a mirror and allows downloading using right-click + save as.

SuperFast LAME status

There were some open issues with the SuperFast LAME implementation when I last wrote about it in the April status update. These have been fixed now and there will be another SuperFast preview release including LAME support very soon after the next alpha. I'm also preparing a technical article about how the MP3 bit reserviour is handled in SuperFast LAME. This should be out within one week from now.

That's it for this month. Be sure to come back in about one month for the next update.