Wrong character encoding for AVI container

[malaterre]

Summary of the bug:
How to reproduce:

% echo $LANG
en_US.UTF-8
% ffmpeg -y -i input.mp4 -c:v copy -c:a copy -metadata title="Un Monstre à Paris" -metadata comment="An exercise with unicode" output.avi
% ffprobe -v error -hide_banner -show_format -print_format json -i output.avi              
[...]
            "title": "Un Monstre à Paris",

The above is incorrect, it should instead prints:

% mediainfo output.avi 
[...]
Movie name                               : Un Monstre à Paris

See:

• ​https://superuser.com/questions/1599675/ffmpeg-character-encodings-used-by-container

[malaterre]

Title as printed from Windows 8.1 session

[malaterre]

For reference:

• ​https://superuser.com/questions/1584842/ffprobe-output-text-wrong-encoding

[malaterre]

% ffmpeg -y -i input.mp4 -c:v copy -c:a copy -metadata title="$(echo 'Un Monstre à Paris' | iconv -t cp1252)" -metadata comment="An exercise with unicode" output.avi

gives:

% mediainfo output.avi
[...]
Movie name                               : Un Monstre à Paris

[mkver]

What makes you believe that the character encoding used by avi is defined at all?

[malaterre]

This is based on the following comment:

• ​https://exiftool.org/faq.html

RIFF: The internal encoding of RIFF strings (eg. in AVI and WAV files) is assumed to be Latin unless otherwise specified by the RIFF CSET chunk or the "-charset RIFF=CHARSET" option.

[malaterre]

I did double check the RIFF specification from:

• ​https://www.aelius.com/njh/wavemetatools/doc/riffmci.pdf

It states:

Specifies the code page used for file elements. If the CSET
chunk is not present, or if this field has value zero, assume
standard ISO 8859/1 code page (identical to code page
1004 without code points defined in hex columns 0, 1, 8,
and 9).

[malaterre]

Replying to mkver:

What makes you believe that the character encoding used by avi is defined at all?

Which specification were you looking at ?

[Carl Eugen Hoyos]

For future tickets: Please remember to test current FFmpeg git head and provide the command line you tested together with the complete, uncut console output to make your tickets valid.