Mosu
12th August 2005, 12:04
Heya guys,
as I do not know which programs out there create timecode files for mkvmerge I'll post this here in the hope that the authors either read this or some of you will point the authors to this post.
The situation
Until today it was necessary for timecode file authors (persons as well as programs) to know which frame type was which and to sort the timecodes accordingly. In a v2 timecode file, and assuming you have the usual picture sequence IPBBP... with 40 fps, the timecode file would have to look like this:
# timcode format v2
0
120
40
80
...
This is both cumbersome and error-prone.
The change
The upcoming mkvmerge 1.5.1 has been fixed to accept sorted timecodes in the timecode files and to re-order them itself as it is necessary. This means that for the same picture sequence IPBBP... the timecode file will now have to look like this:
# timecode format v2
0
40
80
120
...
This should make it a lot easier for folks to write their timecode files, especially with advanced video codecs like AVC which can even have timecode sequences like 0, 120, 80, 40, ... In fact, if mkvmerge encounters a timecode v2 file with timecodes that are not sorted then it will error out. A new format will be introduced, v4, that is identical to v2 but allows unsorted timecodes. This format should never EVER be used because if you think you know better than mkvmerge how to timecode the frames then you're most likely mistaken. But anyway, I don't want to prevent the user from shooting himself in the foot ;)
I'd appreciate it if you guys could forward this to whoever wrote the tools out there creating timecode files. Thanks.
as I do not know which programs out there create timecode files for mkvmerge I'll post this here in the hope that the authors either read this or some of you will point the authors to this post.
The situation
Until today it was necessary for timecode file authors (persons as well as programs) to know which frame type was which and to sort the timecodes accordingly. In a v2 timecode file, and assuming you have the usual picture sequence IPBBP... with 40 fps, the timecode file would have to look like this:
# timcode format v2
0
120
40
80
...
This is both cumbersome and error-prone.
The change
The upcoming mkvmerge 1.5.1 has been fixed to accept sorted timecodes in the timecode files and to re-order them itself as it is necessary. This means that for the same picture sequence IPBBP... the timecode file will now have to look like this:
# timecode format v2
0
40
80
120
...
This should make it a lot easier for folks to write their timecode files, especially with advanced video codecs like AVC which can even have timecode sequences like 0, 120, 80, 40, ... In fact, if mkvmerge encounters a timecode v2 file with timecodes that are not sorted then it will error out. A new format will be introduced, v4, that is identical to v2 but allows unsorted timecodes. This format should never EVER be used because if you think you know better than mkvmerge how to timecode the frames then you're most likely mistaken. But anyway, I don't want to prevent the user from shooting himself in the foot ;)
I'd appreciate it if you guys could forward this to whoever wrote the tools out there creating timecode files. Thanks.