$ eyeD3 a.mp3 

a.mp3   [ 12.41 MB ]
--------------------------------------------------------------------------------
Time: 5:25      MPEG1, Layer III        [ 320 kb/s @ 44100 Hz - Joint stereo ]
--------------------------------------------------------------------------------
No ID3 v1.x/v2.x tag found!
$ eyeD3 --set-text-frame=TIT2:"Траляля и пр." --set-encoding=utf8 --debug a.mp3 

a.mp3   [ 12.41 MB ]
--------------------------------------------------------------------------------
eyeD3 trace> Linking File: a.mp3
eyeD3 trace> mp3 header search starting @ 0
eyeD3 trace> MPEG audio version: 1.0
eyeD3 trace> MPEG audio layer: III
eyeD3 trace> MPEG sampling frequency: 44100
eyeD3 trace> MPEG bit rate: 320
eyeD3 trace> MPEG channel mode: Joint stereo
eyeD3 trace> MPEG channel mode extension: 0
eyeD3 trace> MPEG CRC error protection: False
eyeD3 trace> MPEG original: 0
eyeD3 trace> MPEG copyright: 0
eyeD3 trace> MPEG private bit: 0
eyeD3 trace> MPEG padding: 0
eyeD3 trace> MPEG emphasis: None
eyeD3 trace> MPEG frame length: 1044
eyeD3 trace> mp3 header fffbe040 found at position: 0x4d3
Time: 5:25      MPEG1, Layer III        [ 320 kb/s @ 44100 Hz - Joint stereo ]
--------------------------------------------------------------------------------
No ID3 v1.x/v2.x tag found!
Setting TIT2 frame to 'Траляля и пр.'
Writing tag...
eyeD3 trace> Rendering tag version: v2.4
eyeD3 trace> Linking File: a.mp3
eyeD3 trace> Rendering frame: TIT2
eyeD3 trace> Rendered 54 bytes
eyeD3 trace> Rendering frame: TDTG
eyeD3 trace> Rendered 30 bytes
eyeD3 trace> File rewrite required
eyeD3 trace> Adding 1024 bytes of padding
eyeD3 trace> Rendering v2.4 tag header with size 1108
eyeD3 trace> Setting tag size to 1108
eyeD3 trace> TagHeader rendered 10 bytes
eyeD3 trace> Writing 1118 bytes of tag data
eyeD3 trace> Seeking to beginning of audio data, byte 0 (0)
eyeD3 trace> Tag write complete.  Updating state.
ID3 v2.4:
title: Траляля и пр.          artist: 
album:          year: None
track: 
$ eyeD3 --debug a.mp3 

a.mp3   [ 12.41 MB ]
--------------------------------------------------------------------------------
eyeD3 trace> Linking File: a.mp3
eyeD3 trace> Located ID3 v2 tag
eyeD3 trace> TagHeader [major]: 2
eyeD3 trace> TagHeader [minor]: 4
eyeD3 trace> TagHeader [revis]: 0
eyeD3 trace> TagHeader [flags]: unsync(0) extended(0) experimental(0) footer(0)
eyeD3 trace> TagHeader [size string]: 0x00000854
eyeD3 trace> TagHeader [size]: 1108 (0x454)
eyeD3 trace> sizeLeft: 1108
eyeD3 trace> +++++++++++++++++++++++++++++++++++++++++++++++++
eyeD3 trace> FrameSet: Reading Frame #1
eyeD3 trace> FrameHeader [start byte]: 10 (0xA)
eyeD3 trace> FrameHeader [id]: TIT2 (0x54495432)
eyeD3 trace> FrameHeader [data size]: 44 (0x2C)
eyeD3 trace> FrameHeader [flags]: ta(0) fa(0) ro(0) co(0) en(0) gr(0) un(0) dl(0)
eyeD3 trace> FrameSet: Reading 44 (0x2C) bytes of data from byte pos 20 (0x14)
eyeD3 trace> FrameSet: 44 bytes of data read
eyeD3 trace> TextFrame encoding: utf_8
eyeD3 trace> TextFrame text: Траляля и пр.
eyeD3 trace> sizeLeft: 1054
eyeD3 trace> +++++++++++++++++++++++++++++++++++++++++++++++++
eyeD3 trace> FrameSet: Reading Frame #2
eyeD3 trace> FrameHeader [start byte]: 64 (0x40)
eyeD3 trace> FrameHeader [id]: TDTG (0x54445447)
eyeD3 trace> FrameHeader [data size]: 20 (0x14)
eyeD3 trace> FrameHeader [flags]: ta(0) fa(0) ro(0) co(0) en(0) gr(0) un(0) dl(0)
eyeD3 trace> FrameSet: Reading 20 (0x14) bytes of data from byte pos 74 (0x4A)
eyeD3 trace> FrameSet: 20 bytes of data read
eyeD3 trace> TextFrame encoding: utf_8
eyeD3 trace> TextFrame text: 2009-11-19T16:41:29
eyeD3 trace> TextFrame encoding: utf_8
eyeD3 trace> TextFrame text: 2009-11-19T16:41:29
eyeD3 trace> sizeLeft: 1024
eyeD3 trace> +++++++++++++++++++++++++++++++++++++++++++++++++
eyeD3 trace> FrameSet: Reading Frame #3
eyeD3 trace> FrameHeader [start byte]: 94 (0x5E)
eyeD3 trace> FrameHeader: Null frame id found at byte 98
eyeD3 trace> No frame found, implied padding of 1024 bytes
eyeD3 trace> Tag contains 1024 bytes of padding.
eyeD3 trace> mp3 header search starting @ 45e
eyeD3 trace> MPEG audio version: 1.0
eyeD3 trace> MPEG audio layer: III
eyeD3 trace> MPEG sampling frequency: 44100
eyeD3 trace> MPEG bit rate: 320
eyeD3 trace> MPEG channel mode: Joint stereo
eyeD3 trace> MPEG channel mode extension: 0
eyeD3 trace> MPEG CRC error protection: False
eyeD3 trace> MPEG original: 0
eyeD3 trace> MPEG copyright: 0
eyeD3 trace> MPEG private bit: 0
eyeD3 trace> MPEG padding: 0
eyeD3 trace> MPEG emphasis: None
eyeD3 trace> MPEG frame length: 1044
eyeD3 trace> mp3 header fffbe040 found at position: 0x931
Time: 5:25      MPEG1, Layer III        [ 320 kb/s @ 44100 Hz - Joint stereo ]
--------------------------------------------------------------------------------
ID3 v2.4:
title: Траляля и пр.          artist: 
album:          year: None
track: 
$ echo 'Траляля и пр.' | iconv -t latin1
Траляля и пр.
$