2015-12-17, 16:55
Hollywood feature films and most TV shows on Region 1 DVDs are "soft-telecined," meaning the video is actually encoded progressively at 23.976fps. Pulldown flags are added to instruct the MPEG-2 decoder (e.g. consumer DVD player) to output 29.97fps NTSC video. Commercial ripping software (e.g. MakeMKV) maintains the pulldown flags.
Kodi on the Rasperry Pi 2 currently decodes these videos like a consumer DVD player -- outputting telecined 29.97fps NTSC video. Since interlaced video looks ugly on modern progressive displays, the Pi 2 then applies a de-interlacing filter (e.g. MMAL-Advanced). Unfortunately, the MMAL-Advanced filter cannot fully reconstruct the source image. The picture quality difference between the progressive source video and the MMAL-Advanced de-interlaced output is night-and-day, especially on content like scrolling credits. Any laymen could spot the difference if asked.
A "Force Film" mode that simply ignores the Repeat Field Flag (RFF) would provide a significant picture quality boost for owners of Region 1 content.
EDIT: This is a follow-on to my previous thread on IVTC. As I've learned more about the topic, I feel that thread is better suited to discussing "hard-telecine" content (i.e. content encoded as 29.97fps NTSC video).
Kodi on the Rasperry Pi 2 currently decodes these videos like a consumer DVD player -- outputting telecined 29.97fps NTSC video. Since interlaced video looks ugly on modern progressive displays, the Pi 2 then applies a de-interlacing filter (e.g. MMAL-Advanced). Unfortunately, the MMAL-Advanced filter cannot fully reconstruct the source image. The picture quality difference between the progressive source video and the MMAL-Advanced de-interlaced output is night-and-day, especially on content like scrolling credits. Any laymen could spot the difference if asked.
A "Force Film" mode that simply ignores the Repeat Field Flag (RFF) would provide a significant picture quality boost for owners of Region 1 content.
EDIT: This is a follow-on to my previous thread on IVTC. As I've learned more about the topic, I feel that thread is better suited to discussing "hard-telecine" content (i.e. content encoded as 29.97fps NTSC video).