Placing frame-by-frame chapter points in Adobe Encore?

[mikeja75]

I'm having one issue that I cannot resolve concerning timelines and placing chapter points at specific points.

I am adding chapter points to an mpg2 file and I’m zooming in to place the chapter points at very specific points during the video. I am placing my chapter on one of the tick marks and adobe seems to be recognizing this placement as a valid place to insert a chapter point. Unfortunately, if I place my chapter point at 00:01:29:20, for example, the program actually inserts the chapter point at 00:01:30:20. Why is this happening? All of my research leads me to believe that I'm selecting points where a chapter point can be inserted. When I attempt to manually key in the time that I want the chapter inserted, it still changes my chapter a second or two ahead of where I actually want it placed.

Would it be easier for me to set the chapter points in Premier Pro and then import them into Encore?

I truly don’t think that this is a user error, but perhaps I’m missing something. I’ve used other, less robust, DVD authoring programs in the past and haven’t encountered this type of problem before. I’m pretty impressed with the Encore product and find it hard to believe that version 1.5 has issues regarding specific chapter placement.

I do not want to convert the mpg file to avi to insert specific chapter points due to possible quality loss. Why does TMPGEnc DVD Author, a lesser program in many opinions, allow me to place chapter points frame-by-frame using an mpg file but adobe encore will not?

Thanks,
Mike

[groyal]

I'm not sure this reply ever went through (I see two blank replies on my screen) so I'll try to edit it back in:

A 'chapter point' is defined as a sequence header followed by a GOP header followed by a closed GOP. MPEG encoders typically insert them at scene changes, but this may not be fine enough for your purposes.

The top row of the Encore timeline shows a tickmark for every frame. The bottom row shows a tickmark for every chapter point. If you insert a chapter mark anywhere on the timeline, Encore moves it to the closest preceding legal chapter point automatically.

There are two ways to get around the problem: (a) insert chapter points at precisely the places you want them (most encoders have a facility for doing this), or (b) turn every GOP into a potential chapter point (set output sequence header every 1 GOP and close all GOPs). The advantage of the former is obvious, the latter ensures that there's roughly two legal chapter points per second.

In either case you have to determine your chaptering strategy before you encode the program, because you can't insert them afterward.

[groyal]

[roma_turok]

Unfortunately, if I place my chapter point at 00:01:29:20, for example, the program actually inserts the chapter point at 00:01:30:20

1 second NO BIG DEAL! Its not disaster.

[kickbxn5]

I personally prefer to do chapter points in Encore. That way, there is no mistake

[groyal]

I personally prefer to do chapter points in Encore. That way, there is no mistake

I think you missed the point: A frame has to be coded as a chapter point in order for Encore (or any other authoring program) to use it as one. If you don't plan for them at encode time, you have to make do with what you get, and if that's not close enough you're shit out of luck.

[mikeja75]

Groyal,

Thanks for the response and I have one question for you. You stated:

There are two ways to get around the problem: (a) insert chapter points at precisely the places you want them (most encoders have a facility for doing this), or (b) turn every GOP into a potential chapter point (set output sequence header every 1 GOP and close all GOPs). The advantage of the former is obvious, the latter ensures that there's roughly two legal chapter points per second.

Does the option exist in Adobe Encore to turn every GOP into a potential chapter point by setting the output sequence header using the specifics above? I can insert very specific chapter points using DVD Author, but Adobe doesn't allow me to import these chapter points into their program so I'm back at square one.

[groyal]

Groyal,
Does the option exist in Adobe Encore to turn every GOP into a potential chapter point by setting the output sequence header using the specifics above? I can insert very specific chapter points using DVD Author, but Adobe doesn't allow me to import these chapter points into their program so I'm back at square one.

The authoring program doesn't create chapter marks unless the frame you're pointing to is coded for that purpose. That's why Encore moves the marker to the closest legal chapter point on its own.

If you want to code specific chapter points, or turn all GOPs into a potential chapter point, you have to do this when you encode the file because it's the MPEG encoder that puts them there. The authoring program is too late to change them.

However, there is a utility here -- MPEG Sequence Maker -- that will insert sequence headers between every GOP, turning all the closed ones into chapter points. It can give you much more to work with. Give it a try.