matroska seeking rocks

[chepe36]

i love the way matroska seeks a file.
i have a file that is broken, i fixed it now the problem is that the file has a lot of keyframes like any other movie but the header just knows about the first frame being a keframe :( .

if i put this in avi when i try to seek to a point in the middle of the movie the player will just decode every frame until it reaches the frame i pointed, but in matroska it will go right to that frame without a problem, i know that for many programers this might be a bug but for me its a great feature that should be kep or made optional.

and does anybody knows why this happens?:confused:


sorry for my bad english :D

[Atamido]

Well, there are three ways to seek in a video file.

1. Seek only to keyframes. This means that if you try to seek to a point, it will start playing the video at the keyframe just previous to the seek point. The benefit is that you always get quick seeking. The drawback is that, for example, if you have 10 seconds between keyframes, and you click to seek to the 9th second, you have to watch the previous 8 seconds of video.

2. Render from keyframe. This is like above, but after seeking to the previous keyframe, it renders the video as quickly as possible to get to the seek point. Depending on how it is done, you may or may not see the quickly rendered frames. The benefit to this is it gets you to the point that you selected to seek to with the picture rendered correctly. The drawback is that the video is basicaly frozen until it can render to the point you selected.

3. Seek to point. This means that you go directly to the seek point and start rendering the frames. If its not at a keyframe (very likely) then you will start to a screwy picture as motion compensation and picture additions are made to whatever was previously displayed. The benefit of this is that you immediately get to the point you selected with the audio playing. The drawback is that the picture will be screwey until it hits the next keyframe.


The current official Matroska DS filter uses method 3, and there are some that like it, and some that don't. Either method 1 or 2 will be added to the filter, and there will most likely be a little checkbox letting you decide how you would like to seek. It would be really cool though to have all three methods as options.

[chepe36]

Yes the option to have the 3 methods would be great.

thanx for the info...

[robUx4]

We just added a dialog box in the filter, so sooner or later you'll have lots of things configurable in the filter :)

[duartix]

The current official Matroska DS filter uses method 3 Well this explains a lot.:)