Seeing as there's no option within metaflac to --remove-all-tags-except, in an effort to achieve consistency in tagging I devised a workaround that writes tags to be preserved to stdout and pipes same to another call to metaflac which deletes all tags and then writes back input from stdin.
The general form would be:
metaflac --show-tag tagname1 --show-tag tagname2 --show-tag tagnamex "filename.flac" | metaflac --preserve-modtime --remove-all-tags --import-tags-from=- "filename.flac"
However, I've come up against an issue, as the following call demonstrates:
metaflac --show-tag lyrics x.flac | metaflac --import-tags-from=- x.flac
Running the above should result in the corresponding vorbiscomment simply being rewritten, and it works as intended until it encounters a tag with a CR or LF within the tag, meaning it will not work for the likes of a Lyrics tag, rendering the workaround fruitless.
To illustrate:
metaflac --list x.flac
METADATA block #0
type: 0 (STREAMINFO)
is last: false
length: 34
minimum blocksize: 4608 samples
maximum blocksize: 4608 samples
minimum framesize: 1009 bytes
maximum framesize: 14722 bytes
sample_rate: 44100 Hz
channels: 2
bits-per-sample: 16
total samples: 8627724
MD5 signature: 74bdec14815e8c901cf1f9a87171e2c5
METADATA block #1
type: 4 (VORBIS_COMMENT)
is last: false
length: 73
vendor string: reference libFLAC 1.3.1 20141125
comments: 1
comment[0]: lyrics=FIRST LINE
SECOND LINE
METADATA block #2
type: 1 (PADDING)
is last: true
length: 22445
As soon as there's a CR or LF in a comment, such as in the example above, metaflac fails with the following:
-: ERROR: malformed vorbis comment field "SECOND LINE",
field contains no '=' character
Is there something more I can do my side to work around this or does this now mean there's no solution until this bug is addressed or something like --remove-all-tags-except is implemented?
Seeing as there's no option within metaflac to --remove-all-tags-except, in an effort to achieve consistency in tagging I devised a workaround that writes tags to be preserved to stdout and pipes same to another call to metaflac which deletes all tags and then writes back input from stdin.
The general form would be:
metaflac --show-tag tagname1 --show-tag tagname2 --show-tag tagnamex "filename.flac" | metaflac --preserve-modtime --remove-all-tags --import-tags-from=- "filename.flac"However, I've come up against an issue, as the following call demonstrates:
metaflac --show-tag lyrics x.flac | metaflac --import-tags-from=- x.flacRunning the above should result in the corresponding vorbiscomment simply being rewritten, and it works as intended until it encounters a tag with a CR or LF within the tag, meaning it will not work for the likes of a Lyrics tag, rendering the workaround fruitless.
To illustrate:
metaflac --list x.flacAs soon as there's a CR or LF in a comment, such as in the example above, metaflac fails with the following:
Is there something more I can do my side to work around this or does this now mean there's no solution until this bug is addressed or something like --remove-all-tags-except is implemented?