[MPlayer-users] how to "step backforward" ?

[Oliver Seitz]

> My feeling is that the full frame caching is certainly more general and
> probably easier to implement, and would mean consistent behaviour
> regardless of source. People will scream about the massive memory
> footprint, but it seems like a reasonable application of RAM to me.

I've thought about that, but the method lacks of inflexibility. You then
can only step back to frames you've recently played. I think if there is a
feature for stepping back one frame it should do that, regardless if the
part was played before. If the cache of decoded frames has to be extended
backwards you get almost the behavior of VirtualDub, just a bit more
complex and memory consuming.

I am quite unfamiliar with video file formats. Is it true that frames are
accessed via some sort of "linked list" and is therefore difficult to find
the start of a certain frame? Implementing a cache storing the entry
points of every frame may help. If not the file position but the length of
each frame is stored, 32bit should suffice. 1MB of cache would hold enough
frame lengths for 2.5 hours of video. This "extended index" could be
generated on request by command line switch.

Sorry, I'm dreaming ;-)

Greets,
Kiste