Change:
MP4_CHOICES = ('240p', '360p', '720p', '1080p')
to
MP4_CHOICES = (('240p', '240p'),
('360p', '360p'),
('720p', '720p'),
('1080p', '1080p'))
The reason you are seeing the numbers is, choices
expects a tuple, and since you are not providing it a tuple, it is doing this.
('240p')
is being evaluated as ('2', '4', '0', 'p')
, and it is getting ('2', '4', '0', 'p')[1]
to display in the dropdown. Hence the (4, 6, 2, 0)
.