Hi all, this is the fre:ac development status update covering the months of September and October 2019.

Several improvements have been implemented in these past two months along with some bug fixes. So let's have a look at the changes in detail.

RNNoise model selection

The RNNoise noise reduction code has received an update earlier this year that allows configuring the neural network with different noise reduction models. Several models are provided to accomodate different combinations of speech or general audio with ambient or recording noise.

The model to use in the DSP chain of a conversion is now configurable in fre:ac.

Tagging improvements

Several improvements related to tagging have been implemented in the past two months:

• Chapter support for APEv2 tags
  This brings chapter support to formats like Monkey's Audio (APE), TAK, WavPack and Musepack to enable single file album images that can later be split into individual tracks without the need for a separate cue sheet file.

• Recognize album art when loading cue sheets
  Album art is now recognized when loading tracks to the joblist using cue sheets.

• New tag fields
  In addition to the tag fields mentioned in the 08/2019 update, support for the Performer, Arranger, Producer and Engineer fields has been added.

• CD-Text support on macOS
  The macOS version of fre:ac is now able to read CD-Text information from discs that carry it (mostly Sony releases).

Bug fixes

• Improved drag & drop on macOS
  Drag & drop support on macOS has been a bit wonky up to now, which was found to be caused by mouse pointer updates not reaching the program in drag & drop mode. This is now fixed in the code base and will work much more reliably in upcoming releases.

• Fixes for gapless MP4 AAC
  When using MP4 AAC in non-LC mode (meaning e.g. HE or HEv2 AAC), decoding was not always gapless. This has been fixed to allow sample-exact decoding with any AAC mode.

• Fixed support for very long MP4 AAC files
  Very long AAC files with durations approaching 20 hours need 64 bit fields to store their duration internally. This was not really supported until now and is now implemented.

• Fixed crashes and hangs
  While working on everything mentioned above, several causes for crashes and hangs have been identified and eliminated. Future fre:ac releases should run much more stable with these fixes.

Other news

One more thing worth mentioning here is that the Xiph.org Foundation has released updates to the Ogg and FLAC libraries including patches to support the faster CRC checks I implemented for fre:ac in 2018. This can speed up FLAC by 5% and Ogg FLAC by up to 15%. Performance improvements for lossy formats based on Ogg are usually in the 1-2% range.

Another update is the 19.08 release of the Flatpak runtime. fre:ac's Flatpak package has been updated to make use of the new runtime and I took the chance to also update codecs to their latest version while at it.

That's all for this issue. Make sure to come back for the next update in one or two months.