The period_filter in DASH.to_tracks() only affected track listing but had no effect on n_m3u8dl_re downloads, which re-parsed the raw MPD and downloaded all periods including ads/pre-rolls. This caused DRM decryption failures and corrupted video output.
When periods are filtered during to_tracks(), write a filtered MPD (with rejected periods removed) to a temp file and pass it to n_m3u8dl_re via track.from_file.
Closes#51
d1e6d0812c