Issue with UK Masters Of Cinema Blu-rays. Maybe others?
Posted: Sat May 16, 2020 6:17 am
I've just started noticing an issue with some UK Master of Cinema discs that contain an extra video "segment" that is usually 1 minute long before the movie starts. This "segment" can include things like colour bars, title cards containing technical info, blank video etc. Similarly, I've noticed that some of these Blu-rays also contain extra video at the end of the film that isn’t part of the feature.
Here's a specific example. On the UK Master Of Cinema Blu-ray The African Queen, the MakeMKV Segment Map property is showing a value of 13 and there is a matching file named 00013.m2ts in the Stream folder. When I play this .m2ts file on my computer the video starts by showing a technical title card for 30 seconds followed by blank video for 30 seconds before the movie begins. Also, the total playing time of the video file is 1:46:16. Now, if I use MakeMKV to remux this title, the resulting MKV incorrectly includes this 1 minute "segment” at the start and the resulting file length is also 1:46:16. Basically, MakeMKV is remuxing the entire M2TS file and not starting at the correct point in the video stream.
However, if I use other software like MKVTOOLNIX or CloneBD to remux this title, they create an MKV file that has a correct length of 1:45:18 and does not include that "segment" at the start. This tells me that there must be something else within the Blu-ray files (maybe the playlist which in this case is 00010.mpls?) that instructs Blu-ray players to start 1 minute into that file so the initial "segment" is skipped. MKVTOOLNIX/CloneBD are clearly taking this into account when generating their MKV's.
If anyone knows what the purpose of this extra video is doing on a Blu-ray and specifically, how the Blu-ray instructs the players to start at the correct timestamp I would be interested to hear about this.
More importantly, I'm hoping this issue can be fixed in a future version of MakeMKV.
Here is that technical title card that is shown for the first 30 seconds.
Here is the Blu-ray loaded in MakeMKV and it is incorrectly showing a video length of 1:46:16
Here is the Blu-ray loaded in CloneBD and it is correctly showing a video length of 1:45:18
Here is the Blu-ray loaded in MKVTOOLNIX and it is correctly showing a video length of 1:45:18
Here's a specific example. On the UK Master Of Cinema Blu-ray The African Queen, the MakeMKV Segment Map property is showing a value of 13 and there is a matching file named 00013.m2ts in the Stream folder. When I play this .m2ts file on my computer the video starts by showing a technical title card for 30 seconds followed by blank video for 30 seconds before the movie begins. Also, the total playing time of the video file is 1:46:16. Now, if I use MakeMKV to remux this title, the resulting MKV incorrectly includes this 1 minute "segment” at the start and the resulting file length is also 1:46:16. Basically, MakeMKV is remuxing the entire M2TS file and not starting at the correct point in the video stream.
However, if I use other software like MKVTOOLNIX or CloneBD to remux this title, they create an MKV file that has a correct length of 1:45:18 and does not include that "segment" at the start. This tells me that there must be something else within the Blu-ray files (maybe the playlist which in this case is 00010.mpls?) that instructs Blu-ray players to start 1 minute into that file so the initial "segment" is skipped. MKVTOOLNIX/CloneBD are clearly taking this into account when generating their MKV's.
If anyone knows what the purpose of this extra video is doing on a Blu-ray and specifically, how the Blu-ray instructs the players to start at the correct timestamp I would be interested to hear about this.
More importantly, I'm hoping this issue can be fixed in a future version of MakeMKV.
Here is that technical title card that is shown for the first 30 seconds.
Here is the Blu-ray loaded in MakeMKV and it is incorrectly showing a video length of 1:46:16
Here is the Blu-ray loaded in CloneBD and it is correctly showing a video length of 1:45:18
Here is the Blu-ray loaded in MKVTOOLNIX and it is correctly showing a video length of 1:45:18