year vs. releasetime

[winxi]

Hi,
when converting from flac to mp3 with ffmpeg, there is an ffmpeg option (in fact the default) to preserve tags. However, ffmpeg seems to write the YEAR tag from the flac file to a RELEASETIME tag in the mp3 file (at least these names appear in mp3tag).
With 'Date' in the indexTags property, MinimServer will index the YEAR tag in the flac-file correctly, but not the RELEASETIME tag in the mp3-file.
Is this a non-standard behaviour of ffmpeg? Should I rename the RELEASETIME tag in the mp3-files to YEAR?

Thanks in advance!

[simoncn]

(19-03-2013 19:39)winxi Wrote:  Hi,
when converting from flac to mp3 with ffmpeg, there is an ffmpeg option (in fact the default) to preserve tags. However, ffmpeg seems to write the YEAR tag from the flac file to a RELEASETIME tag in the mp3 file (at least these names appear in mp3tag).
With 'Date' in the indexTags property, MinimServer will index the YEAR tag in the flac-file correctly, but not the RELEASETIME tag in the mp3-file.
Is this a non-standard behaviour of ffmpeg? Should I rename the RELEASETIME tag in the mp3-files to YEAR?

Thanks in advance!

The tag you're seeing as RELEASETIME in Mp3tag is the ID3v2 TDRL frame.

The TDRL frame was added in ID3v2.4 with the description 'release time'. Also added in ID3v2.4 were the TDRC frame (described as 'recording time') and the TDOR frame (described as 'original release time'). These frames aren't valid in ID3v2.3.

It is standard practice to map the ID3v2.4 TDRC frame to the FLAC/Vorbis tag DATE (displayed by Mp3tag as YEAR for historical reasons), and MinimServer will support this mapping in the next release. The next release of MinimServer will also support the mapping of TDOR to ORIGINALDATE (displayed by Mp3tag as ORIGYEAR). These mappings will work only if your MP3 files contain ID3v2.4 tags, so it would be a good idea to verify this.

Most tagging programs and servers seem to ignore the TDRL frame, giving preference to TDRC and TDOR, and this is my current intention for MinimServer. I think the best solution is to use Mp3tag to change the TDRL (Mp3tag RELEASETIME) frames to TDRC (Mp3tag YEAR), assuming that your tags are in ID3v2.4 format.

Note: Mp3tag allows the TDRC frame (YEAR) to contain a full date, not just a year.

[winxi]

(19-03-2013 20:25)simoncn Wrote:  The tag you're seeing as RELEASETIME in Mp3tag is the ID3v2 TDRL frame.

The TDRL frame was added in ID3v2.4 with the description 'release time'. Also added in ID3v2.4 were the TDRC frame (described as 'recording time') and the TDOR frame (described as 'original release time'). These frames aren't valid in ID3v2.3.

It is standard practice to map the ID3v2.4 TDRC frame to the FLAC/Vorbis tag DATE (displayed by Mp3tag as YEAR for historical reasons), and MinimServer will support this mapping in the next release. The next release of MinimServer will also support the mapping of TDOR to ORIGINALDATE (displayed by Mp3tag as ORIGYEAR). These mappings will work only if your MP3 files contain ID3v2.4 tags, so it would be a good idea to verify this.

Many thanks for the detailed explanation!

Quote:Most tagging programs and servers seem to ignore the TDRL frame, giving preference to TDRC and TDOR, and this is my current intention for MinimServer. I think the best solution is to use Mp3tag to change the TDRL (Mp3tag RELEASETIME) frames to TDRC (Mp3tag YEAR), assuming that your tags are in ID3v2.4 format.

Note: Mp3tag allows the TDRC frame (YEAR) to contain a full date, not just a year.

I followed your suggestion and changed TDRL to TDRC - now everything works fine . The TDRC frames contain the full date now, but I make use of the MinimServer indexValue.yearOnly tag option to show just the year.

[simoncn]

(19-03-2013 21:59)winxi Wrote:  I followed your suggestion and changed TDRL to TDRC - now everything works fine . The TDRC frames contain the full date now, but I make use of the MinimServer indexValue.yearOnly tag option to show just the year.

I just found a bug in the code that handles the TDRC frame. This would cause the TDRC frame to be ignored by MinimServer. This will be fixed in the next release.

Is it possible that the date information you're seeing in MinimServer is coming from the TYER frame rather than the TDRC frame? Do your MP3 files contain the TYER and/or TDAT frames?

[winxi]

(20-03-2013 17:16)simoncn Wrote:  

(19-03-2013 21:59)winxi Wrote:  I followed your suggestion and changed TDRL to TDRC - now everything works fine . The TDRC frames contain the full date now, but I make use of the MinimServer indexValue.yearOnly tag option to show just the year.

I just found a bug in the code that handles the TDRC frame. This would cause the TDRC frame to be ignored by MinimServer. This will be fixed in the next release.

Is it possible that the date information you're seeing in MinimServer is coming from the TYER frame rather than the TDRC frame? Do your MP3 files contain the TYER and/or TDAT frames?

I'm not sure how to confirm whether my files contain the TYER/TDAT frames or not. I've just used Mp3tag with the standard mapping setting and I have observed the following for the converted mp3-file which contains only the ID3v2.4 tag and no ID3v2.3 tag:

1) date value in RELEASETIME (TDRL) and nowhere else -> not indexed by MinimServer
2) date value in RELEASETIME (TDRL) and YEAR (TDRC) -> indexed by MinimServer

However, I'm not sure whether YEAR in 2) coresponds to the TDRC frame. For now, I've relied on this table. But I can confirm that the file contains just the ID3v2.4 tag.

[simoncn]

(20-03-2013 20:53)winxi Wrote:  I'm not sure how to confirm whether my files contain the TYER/TDAT frames or not. I've just used Mp3tag with the standard mapping setting and I have observed the following for the converted mp3-file which contains only the ID3v2.4 tag and no ID3v2.3 tag:

1) date value in RELEASETIME (TDRL) and nowhere else -> not indexed by MinimServer
2) date value in RELEASETIME (TDRL) and YEAR (TDRC) -> indexed by MinimServer

However, I'm not sure whether YEAR in 2) coresponds to the TDRC frame. For now, I've relied on this table. But I can confirm that the file contains just the ID3v2.4 tag.

Thanks for sending the sample file. I've figured this out now. The code to handle TDRC was correct in 0.63, but a recent change in this area of the code was causing the problem.

FYI, the file contains a TDRC frame, a TDRL frame and a TXXX/ORIGINALDATE frame.

[winxi]

(20-03-2013 22:32)simoncn Wrote:  Thanks for sending the sample file. I've figured this out now. The code to handle TDRC was correct in 0.63, but a recent change in this area of the code was causing the problem.

Thanks for sorting this out! Just a few comments:

Quote:The TDRL frame was added in ID3v2.4 with the description 'release time'. Also added in ID3v2.4 were the TDRC frame (described as 'recording time') and the TDOR frame (described as 'original release time'). These frames aren't valid in ID3v2.3.

Quote:Most tagging programs and servers seem to ignore the TDRL frame, giving preference to TDRC and TDOR, and this is my current intention for MinimServer.

I tagged the flac files using Musicbrainz Picard and converted it to mp3 using ffmpeg. The MusicBrainz database distinguishes between the original release time and the release time. This makes sense especially for reissues or remastered albums.

Quote:FYI, the file contains a TDRC frame, a TDRL frame and a TXXX/ORIGINALDATE frame.

The output mp3 files have the TDRL and the TXXX/ORIGINALDATE frame containing the correct values according to the descriptions release time and original release time. The TDRC frame was added by myself. In the MinimServer indexTags property I use 'Date' to index the TDRC frame and 'originaldate' to index the TXXX/ORIGINALDATE frame separately.
However, considering the descriptions, the standard practice to use TDRC (recording time) in this context seems to me to be the least appropriate option.

[simoncn]

(21-03-2013 00:04)winxi Wrote:  I tagged the flac files using Musicbrainz Picard and converted it to mp3 using ffmpeg. The MusicBrainz database distinguishes between the original release time and the release time. This makes sense especially for reissues or remastered albums.

The output mp3 files have the TDRL and the TXXX/ORIGINALDATE frame containing the correct values according to the descriptions release time and original release time. The TDRC frame was added by myself. In the MinimServer indexTags property I use 'Date' to index the TDRC frame and 'originaldate' to index the TXXX/ORIGINALDATE frame separately.
However, considering the descriptions, the standard practice to use TDRC (recording time) in this context seems to me to be the least appropriate option.

I have some sympathy with this, so I will add a mapping from TDRL to RELEASEDATE in the next release of MinimServer. If you want MinimServer to interpret RELEASEDATE as DATE for indexing and display purposes, you'll be able to use the new aliasTags property to do this.

There's a useful list of mappings here, starting around line 331. These names happen to match the names I'm using for MinimServer, although MinimServer doesn't (yet) support everything in this list.

[winxi]

(21-03-2013 14:13)simoncn Wrote:  I have some sympathy with this, so I will add a mapping from TDRL to RELEASEDATE in the next release of MinimServer. If you want MinimServer to interpret RELEASEDATE as DATE for indexing and display purposes, you'll be able to use the new aliasTags property to do this.

There's a useful list of mappings here, starting around line 331. These names happen to match the names I'm using for MinimServer, although MinimServer doesn't (yet) support everything in this list.

Many thanks Simon, this sounds great!