python3: write ogg vorbis (vorbiscomment) cover art (METADATA_BLOCK_PICTURE)

gistfile1.py

from PIL import Image
 
cover = Image.open(self.get_art_path(track))
cover_mime = Image.MIME[cover.format]
cover_width = cover.size[0]
cover_height = cover.size[1]
cover_bitdepth = cover.bits
 
with open(self.get_art_path(track), 'rb') as image_file:
    cover_data = image_file.read()
 
METADATA_BLOCK_PICTURE = struct.pack(
    #https://github.com/imalone/oggflacblock/blob/master/oggflacblock.pl#L278
    #(L[2]A[%d]LA[%d]L[5]a[%d])>
    '>2L%dsL%ds5L%ds' % (len(cover_mime), 0, len(cover_data)),
    3, # The picture type according to the ID3v2 APIC frame: = Cover (front)
    len(cover_mime), # The length of the MIME type string in bytes.
    cover_mime.encode(encoding='ascii'), # The MIME type string, in printable ASCII characters 0x20-0x7e.
    0, # The length of the description string in bytes.
    b'', # The description of the picture, in UTF-8.
    cover_width, #The width of the picture in pixels.
    cover_height, # The height of the picture in pixels.
    cover_bitdepth, # The color depth of the picture in bits-per-pixel.
    0, # For indexed-color pictures (e.g. GIF), the number of colors used, or 0 for non-indexed pictures.
    len(cover_data), # The length of the picture data in bytes.
    cover_data #The binary picture data.
)
 
tags.append('METADATA_BLOCK_PICTURE=%s' % base64.b64encode(METADATA_BLOCK_PICTURE).decode(encoding='ascii'))