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IDProjectCategoryView StatusDate SubmittedLast Update
0001616KdenliveMLTpublic2010-05-25 10:312011-03-19 20:07
Assigned Toddennedy 
Platform64 bitOSKubuntu LinuxOS Version8.10
Product Version0.7.7.1 
Target VersionFixed in Version 
Summary0001616: Imported video into new project - cannot seek backwards on timeline
DescriptionIf I import this clip into a new project

I can play the file but if I change timeline backwards the audio will reflect the change but the video will carry on from the last from it was on.

If I play the video until just before the end of the clip, move the timeline back to the beginning then continue to play the video it will finish the end of the clip and then kdenlive will just close (crash)
Steps To ReproduceDownload clip
import into project
add video to timeline
move timeline to near end of video
move timeline to beginning of video

audio should be seeked properly but video is still in the last old position. once video reaches past end of the clip kdenlive crashes.
Additional Informationseeking forward works past the last position works.

link in case of upload failure
TagsNo tags attached.
Build/Install Method(select)
Attached Files? file icon charl.flv [^] (2,980,078 bytes) 2010-05-25 10:31
? file icon croatia mountain view.avi [^] (19,104,708 bytes) 2011-03-19 14:43

- Relationships

-  Notes
ttill (developer)
2010-05-27 21:48

Can reproduce.
Seeking works fine in ffplay, but in kdenlive only audio is seeked.
ttill (developer)
2010-05-27 21:50

Same problem in melt (MLT's command line tool).
gnopaks (reporter)
2011-03-13 12:36

10 months later this problem persists in melt 0.5.10 and kdenlive 0.7.8
ddennedy (developer)
2011-03-15 04:05

I looked into this for a while, but I have not yet figured it out.
gnopaks (reporter)
2011-03-19 14:46

I attached croatia mountain view.avi (Biokovo mountain range) to ask if this file is affected by the same error. It is impossible to seek in the attached file in kdenlive. Avidemux "copy" fixes the file so that it can be used in kdenlive. However even the fixed file does not seek properly in ffplay and even the broken file seeks properly in mplayer. The attached file comes from Canon HF10 and was transcoded from MTS with simple "ffmpeg -qscale 4" command.
ddennedy (developer)
2011-03-19 20:07

Both files fail an initial test to see if the file supports seeking to key frames. If I relax the test to request a seek to any kind of frame, then charl still fails but croatia succeeds. Then, the croatia video seeking mostly works but still exhibits some problems. Next, when I relax the main seek call from non-keyframe to any-frame, the croatia video seeks and plays rather well. However, I am not yet committed to apply this change. Video editing requires frequent and accurate seeking. Therefore, I currently lean towards being pessimistic instead of optimistic about seeking support - even if that means some files that ought to be supported are rejected.

One change to make is that Kdenlive should check the "seekable" property of a file added to the Project Tree. On the other hand, it provides this Transcode function in the Project Tree that can be used to "fix it," and rejection would prevent its usage in many cases. Therefore, I suppose a warning dialog is in order with a suggestion to Transcode it.

As for the seeking flags change in MLT per the first paragraph, I must make a new release in the coming days, and this change is definitely not going into that release because it requires much regression testing. In the meantime, you can fix the original file by remuxing it to mov or mkv:
ffmpeg -i in.avi -vcodec copy -acodec copy
ffmpeg -i in.avi -vcodec copy -acodec copy out.mkv

- Issue History
Date Modified Username Field Change
2010-05-25 10:31 genjix New Issue
2010-05-25 10:31 genjix File Added: charl.flv
2010-05-27 21:46 ttill Status new => acknowledged
2010-05-27 21:48 ttill Note Added: 0005211
2010-05-27 21:50 ttill Note Added: 0005212
2010-06-04 20:44 ttill Category File Loading => MLT
2011-03-13 12:36 gnopaks Note Added: 0006572
2011-03-15 04:04 ddennedy Assigned To => ddennedy
2011-03-15 04:04 ddennedy Status acknowledged => assigned
2011-03-15 04:05 ddennedy Note Added: 0006577
2011-03-19 14:43 gnopaks File Added: croatia mountain view.avi
2011-03-19 14:46 gnopaks Note Added: 0006605
2011-03-19 20:07 ddennedy Note Added: 0006608

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