|Originally posted by dszlucha
Does this apply when I hold SHIFT while using Virtualdub with MPEG2 capability? Or only when I don't use I-frames?
From the rtvtools docs:
|Since RVTEDIT is intended to use times from EVTDUMP, the times used in the
edit list are based off the .ndx/.evt clock (which is different from the
stream clock). If you are creating an edit list manually, you must use an
application that will give you frame times (not MPEG times) or your results
will be off. The -t1 flag allows using frame times from an external
application. This only works for original RTV 5K streams (not converted or
VirtualDub-MPEG2, 1.5.4 or later, is recommended for manually finding edit
times. For best results, hold SHIFT to snap to I-frames and pick the one
where you want the edit to occur. Once you've created the edit list, use:
rtvedit -t1 <edit-script>
This will adjust the script times to the closest editable locations in the
stream. This should be much more accurate (within 2 frames from my testing
with medium quality streams).
Basically, any external MPEG editor will use a different time-base than the replay files.
Therefore, you need the switch unless you rely on the evt times themselves.
I-frames don't matter in regard to the "t1" switch, but you SHOULD snap to I-frames
when locating cut points.
Here's a slightly flawed analogy:
Suppose two guys, Ernie and Bert are driving from LA to Vegas. They take separate cars,
but drive the same speed. Each one keeps a log in which he writes down the time every 10 miles.
However, Ernie's watch is SLIGHTLY faster than Bert's.
Now, if you want to know at what time Ernie was at 100 miles, you'd have to rely on his watch.
Likewise, all of Bert's logs are based on his watch. So, if you want to know how long it takes
to get to a specific point along the route, you need to know whose watch was used to record the times.
Similarly, since the Replay "evt" times are a slightly different speed than most MPEG editors,
rtvedit needs to know whose watch was used to record the log. That's what the "t1" switch does:
it distinguishes between the default "evt" times, and the external editor times.