[SOLVED] Incomplete ArtWork Scan

[TheOldPresbyope]

@Miss Sissy Princess 
The FLAC specification looks quite complete to my eyes.
https://xiph.org/flac/format.html
https://xiph.org/vorbis/doc/v-comment.html

FLAC codec and associated utilities from xiph.org are IME the most widely used in Linux audio precisely because of their high quality implementations, efficient algorithms and well defined specifications.

ALAC is typically only found in collections where iTunes is or was used. Even after Apple released the ALAC specification back in 2011 as Open Source the adoption rate has been almost nil in the Linux audio community because FLAC has been in use since 2001 and was already a proven winner with high quality implementations, speed, efficiency and metadata support.

Oddly Apple still does not support FLAC in the iTunes / Apple Music eco system while most Linux audio players support a wide variety of formats including ALAC.

Just a quick update: I went through my collection and found 1%-2% missing art work, mostly in AIFF files, even if most were fine. After the conversion, I only have a handful of issues out of hundreds of albums, and all for different reasons that I am solving now

It sounds like the following tip may no longer be relevant for you, but I found that converting your .m4a files to .flac files using ffmpeg worked well. 

The "Audio info" popup in moOde is reporting the converted files are encoded as 24 bit/44.1 kHz FLAC. They are playing and coverart is being displayed in the Library and Playback views.

The conversion is easy-peasy. For example

Code:

pi@moode:~ $ ffmpeg -i '01 Dance Yrself Clean.m4a' '01 Dance Yrself Clean.flac'

where the -i option indicates the next file name is the input file and the format of the resulting output file is inferred from its extension (.flac in this case). Note that the output file name can be whatever you like. Consult the ffmpeg man page for more information.

I notice that in the middle of the diagnostics printed during the conversion process, ffmpeg reports

Code:

[swscaler @ 0x77c420] deprecated pixel format used, make sure you did set range correctly
[swscaler @ 0x77c420] No accelerated colorspace conversion found from yuv420p to rgb24.
[flac @ 0x75c2c0] Frame rate very high for a muxer not efficiently supporting it.
Please consider specifying a lower framerate, a different muxer or -vsync 2
[flac @ 0x75d3a0] encoding as 24 bits-per-sample

but I don't know if this information is relevant to the issue at hand.

Okay, coffee break is over. Gotta go move boxes (anybody remember Monty Python's early sketch "The Society of Putting Things on Top of Other Things"?).

Regards,
Kent