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Slider not working

Started by andyavi, January 22, 2014, 04:18:42 AM

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andyavi

HI,

I have an avi where I want to cut certain pieces. The slider doesn't work. I can only play the video or skip frame by frame. I found via google some older posts which sounded a bit like that the slider is kind of not supposed to work, which I cannot imagine. I tried on Win and Linux, both have the same issue. version 2.6.7. Can someone shed some light on it what I can do?

Thanks, A.

mean

If it is h264 in avi, it will not work
Maybe put the video into mkv with mkvmerge and edit the mkv

andyavi

yes the codec is H264. Why is the slider not working here, is that rather a bug or is that rather something in the nature of avi/h264? When watching the movie with a normal player I can do fast forward and use the slider in the movie player so I assume it is a bug. Is that being planned to get fixed?

Thanks.

AQUAR

#3
Don't think its a bug but a limitation of the avi container.

The guru's here can give an accurate explanation, but the gist of it is:

The avi container is just not suited to store H.264 as an editable video stream.
With H.264 most video frames are "virtual" frames constructed in part from other previous and future frames.
Further more these other frames may also be "virtual" and be called out of order.
AVI is strictly '1 frame into the decoder and one frame out of the decoder'  and already needs tricks to work with codecs with simple implementations of "virtual" frames (like XVID).

On top of that Avidemux 2.6.x relies on time codes for frame seeking and so avi further breaks down as a suitable container.
Hence H.264 in AVI means there is no seeking to a frame for cut editing in avidemux 2.6.x, thus no slider function.

In a media player the slider is not for selecting a video cut point, its just an approximate positioning point in a movie (idr frames).
And the fact that you can still play the H.264 means the decoder is doing some buffering type tricks to get at those more frames in for 1 frame out.

Best to use a more modern container like MKV or MP4.