Bug 500418

SUMMARY
`©mvi` (Movement Number) tags are saved incorrectly – as text, rather than as integers.

STEPS TO REPRODUCE
1. Use Kid3 to add an ©mvi tag to an MP4 file. Set the value to a number. (Note that the field name has to be entered as `©mvi` – for some reason, “Movement Number” can’t be typed in even though that’s what it displays as. If you type in “Movement Number”, it’s saved as a `----` user text frame.)
2. Open the file in, say, Mp3tag.
3. Look at the “Movement” tag in the extended tags.

(Correct `©mvi` tags also parse incorrectly.)

OBSERVED RESULT
The tag is garbled.

EXPECTED RESULT
The tag should show up as the number entered.

ADDITIONAL INFORMATION
This result is only observed using the Mp4v2 plugin – not the TagLib plugin.