Cannot slide timeline bar when opening video made with Avidemux

[theat934]

Hi everyone; this is a question probably related to codec settings.

I used Avidemux to encode .MTS camera footage. I used the x.264 codec with some custom settings (by consulting the fine tutorial at http://www.avidemux.org/admWiki/doku.php?id=tutorial:h.264). Then I saved my output successfully into an .avi file.

Later on, I opened this .avi file in Avidemux to create a few shorter clips. At that point, I noticed I was unable to use the timeline slide bar to jump to any arbitrary frame. I can always use the arrows to navigate forward/backward on a frame-by-frame basis. Yet, whenever I would click on the slider to take it to an arbitrary position in the clip, the slider would be stuck at the beginning of the clip. In the original .MTS video I was able to use the slider to jump to any I-frame or P-frame in the clip, but the transcoded .avi video I produced had no longer this capability.

I assume that the above behavior might have to do with some x.264 codec setting that I have overlooked. Would anyone happen to know what setting I would possibly need to tweak in the x.264 configuration, so that I can get the slider functionality in the target video?

Thanks!

[Jan Gruuthuse]

think you should not use avi for this, perhaps more like mp4v2 or mkv. And perhaps upgrade to avidemux 2.6.3.

[theat934]

Thank you Jan, I am actually running the latest 2.6.3. I posted my question here, because I see the 2.6.x technical discussions revolve mostly around 2.6.x development

I have experienced the issue I am seeking feedback for in previous versions, too, so I hope the question is unrelated to the software version. I notice the same behavior regardless whether I save into an AVI or MP4 container. For these reasons, I assume the issue might be rather related to the x.264 settings.

Alternatively, it could be that only uncompressed raw video might be arbitrarily accessible by the slide bar, such as the .MTS clips from a video camera. If this is so, then it would make better sense why I cannot use the Avidemux slide bar to navigate around compressed videos produced with a codec like x.264.

[Jan Gruuthuse]

Try removing filename related name.idx2, avidemux should reindex.
If none windows avidemux: use QT version a not GTK and you have installed:
avidemux3-core-2.6.3-8592-Linux
avidemux3-plugins-COMMON-2.6.3-8592-Linux
avidemux3-qt4-2.6.3-8592-Linux
avidemux3-plugins-QT4-2.6.3-8592-Linux
avidemux3-cli-2.6.3-8592-Linux   installable from r8592
avidemux3-plugins-CLI-2.6.3-8592-Linux
avidemux3-plugins-SETTINGS-2.6.3-8592-Linux   new from r8592

If only video with one audio track: install ffmpeg and try:

Code Select Expand

ffmpeg -i input.avi -acodec copy -vcodec copy output.avi
if that gives none workable result:

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ffmpeg -i input.avi -acodec copy -vcodec copy output.mkv

replace input.avi by the real filename.
no spaces allowed or diacritic characters

[theat934]

Thank you again, Jan. I work on MasOS and use the available builds, so I am less flexible to pick components. The file I am interested in did not rebuild upon import, or at least did not visibly produce an .idx2 file. But it did spend a few moments building the time map. I also followed your suggestions with ffmpeg to no solution.

Another way to express what I experience is that I am unable to navigate to the next I-frame. When I push the "up" button or go to "Go">"Next Intra Frame", then either nothing happens or I get the error "Cannot go to next keyframe". I know my video has more than one I-frames because I specified so when encoding, and I can also see them when I move forward frame-by-frame with the right arrow in Avidemux.

In any case, this is not that big of a deal at this time. I've been only trying to learn and understand more about the topic.

[Jan Gruuthuse]

sorry for the limited attempt to explain.
2.6 branch is bad idea to process frame based video, it is time based: not all frames are there, some are virtual and reconstructed from previous/upcoming information.
2.5 branch should work for frame based.
avi container (box) and newer codecs don't mix well either: frame versus none frame based compression algorithms

[theat934]

Problem understood and solved.
I opened the .AVI video in question in v.2.5.x, and I could indeed navigate the slider just fine to any of the I-frames. Under v.2.6.x it is impossible to even navigate by time by using the "Time" button in the interface.
Yet, upon creating an .MP4 version, I was able to navigate through it under v.2.6.x, too.
Many thanks for the insight, Jan.