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lordmulder / LameXP

Audio Encoder Front-End
http://lordmulder.github.io/LameXP
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Missing "Discnumber" from tag #39

Open ghost opened 8 years ago

ghost commented 8 years ago

I am using LameXP Version 4.13 Final-1, Build 1852 to convert from FLAC to MP3 and AAC (using Nero AAC or QAAC 2.58 codecs). All the files I converted have all tags transfered from source except "Discnumber". I also converted the same file, using the same AAC and MP3 codecs with using foobar2000 and Discnumber tag is transferred.

Here are the file types where Discnumber is missing after conversion:

Here are the file types where Discnumber is present after conversion:

I did not test:

Attached to this ticket is a screenshot of the files loaded in Mp3tag v2.78. capture

lordmulder commented 8 years ago

As explained many times before, "retaining" meta tags is not as simple as people may assume. LameXP supports many output formats, and even more input formats. Each of these file formats stores meta tags in its own different way ("the good things about standards is that there so many to choose from").

Thus, retaining meta tags requires three steps: (1) Extract the meta tags from the particular input format, (2) store the extracted meta tags in an internal data structure, and (3) re-embed the stored meta tags into the particular output format. Getting this task done for N input formats and M output formats is not trivial.

The internal "meta data" structure of LameXP has been designed to reflect the intersection of what is supported by all the various file formats that we have to deal with. And this pretty much comes down to the fields that are supported by ID3v1. It does not currently include "Discnumber" as well as some others.

1024mb commented 6 years ago

I'm having the same issue and I only convert from flac to flac, but not only discnumber is lost, I'm also missing disctotal, albumartist and tracktotal.

I will try beta now.

Edit: Tried beta and got same result.

lordmulder commented 6 years ago

Sorry, but as already explained above, the only "meta tags" currently supported, i.e. the only meta tags that will be detected from the original input and that will re-embedded into the converted file, are those:

https://github.com/lordmulder/LameXP/blob/8d93ae87dd04ebaa772cde6710583bc06c613088/src/Model_AudioFile.h#L34-L86

Maybe more will be added in the future. But you have to keep in mind that we support N input formats and M output formats and all N×M combinations have to work! FLAC is just one format out of many.

Regards.