Marker tracking erratic when used directly on video but perfect on imported image sequence of same video for stabilization purpose. #48551

New Issue

Andy · 2016-05-30T22:12:07+02:00

Andy commented

2016-05-30 22:12:07 +02:00

Hey devs

I have noticed feature tracking behavior behaves erratically when used on relatively long videos as compared to its use on image sequence of same videos. Manually done tracking data appears to get offset or out of sync. slightly on videos when stabilization is previewed. When same is done on image sequence instead of movie clip tracking data remains perfectly synced.

Here are steps to reproduce.

Take a relatively long video (3 min. long in my case) break it down to image sequence.

Make two blends open 'video sequence editor' in each.

Import video clip in one and image sequence in another.

Add a marker on common feature with all settings default. Track it precisely enough on both blends and lock the track.

Add track on 2d stabilization and check it (enable it). Enable Display Stabilization.

Go to start of timeline and replay movie.

I found one with image sequence behaved as expected and tracking data remains as it is, but other behaves erratically it some times remains in sync for a portion of clip but for most of it is out of sync, this also changes with reloads or replays. Notice worthy thing is it doesn't forget tracking data it is just not perfect and jittery but still remains around the tracked feature as if it is offset.

When rendered result is same as previewing suggests ie jittered from blend using video clip and perfectly stabilized form blend using image sequence.

This user on blender stackexchange faced same issue and one answer suggested it could be caused by inconsistent decoding of particular video codec by Blender.

https://blender.stackexchange.com/questions/6196/my-markers-in-the-movie-clip-editor-keep-moving-around-what-gives

OS: Win 7,
Blender version 2.76 (32 bit)
CPU: 3Ghz (Dual core Intel)
RAM: 4GB

Hey devs I have noticed feature tracking behavior behaves erratically when used on relatively long videos as compared to its use on image sequence of same videos. Manually done tracking data appears to get offset or out of sync. slightly on videos when stabilization is previewed. When same is done on image sequence instead of movie clip tracking data remains perfectly synced. Here are steps to reproduce. Take a relatively long video (3 min. long in my case) break it down to image sequence. Make two blends open 'video sequence editor' in each. Import video clip in one and image sequence in another. Add a marker on common feature with all settings default. Track it precisely enough on both blends and lock the track. Add track on 2d stabilization and check it (enable it). Enable Display Stabilization. Go to start of timeline and replay movie. I found one with image sequence behaved as expected and tracking data remains as it is, but other behaves erratically it some times remains in sync for a portion of clip but for most of it is out of sync, this also changes with reloads or replays. Notice worthy thing is it doesn't forget tracking data it is just not perfect and jittery but still remains around the tracked feature as if it is offset. When rendered result is same as previewing suggests ie jittered from blend using video clip and perfectly stabilized form blend using image sequence. This user on blender stackexchange faced same issue and one answer suggested it could be caused by inconsistent decoding of particular video codec by Blender. https://blender.stackexchange.com/questions/6196/my-markers-in-the-movie-clip-editor-keep-moving-around-what-gives OS: Win 7, Blender version 2.76 (32 bit) CPU: 3Ghz (Dual core Intel) RAM: 4GB

Andy commented

2016-05-30 22:12:07 +02:00

Changed status to: 'Open'

Andy commented

2016-05-30 22:12:07 +02:00

Added subscriber: @Bugsh

Andy commented

2016-05-31 03:10:58 +02:00

Quote: "Make two blends open 'video sequence editor' in each."

I meant to say 'Movie clip editor' not 'video sequencer editor' in OP.

Quote: "Make two blends open 'video sequence editor' in each." I meant to say 'Movie clip editor' not 'video sequencer editor' in OP.

Andy commented

2016-05-31 03:11:02 +02:00

Quote: "Make two blends open 'video sequence editor' in each."

I meant to say 'Movie clip editor' not 'video sequencer editor' in OP.

Quote: "Make two blends open 'video sequence editor' in each." I meant to say 'Movie clip editor' not 'video sequencer editor' in OP.

Sergey Sharybin commented

2016-06-07 17:55:41 +02:00

Added subscriber: @Sergey

Sergey Sharybin commented

2016-06-07 17:55:41 +02:00

Changed status from 'Open' to: 'Archived'

Sergey Sharybin closed this issue

2016-06-07 17:55:41 +02:00

Sergey Sharybin self-assigned this 2016-06-07 17:55:41 +02:00

Sergey Sharybin commented

2016-06-07 17:55:41 +02:00

This is usually happens when video has stuff like variable framerate or badly encoded frames in them. This causes seek to work unreliably. This is why it is recommended to build Timecode in order to make seek in the video be robust.

Here's quick explanation of them https://wiki.blender.org/index.php/User:Nazg-gul/ProxyAndTimecode

Surely improvements are always possible, like building timecode automatically, but it's not really bug. Thanks for the report anyway.

This is usually happens when video has stuff like variable framerate or badly encoded frames in them. This causes seek to work unreliably. This is why it is recommended to build Timecode in order to make seek in the video be robust. Here's quick explanation of them https://wiki.blender.org/index.php/User:Nazg-gul/ProxyAndTimecode Surely improvements are always possible, like building timecode automatically, but it's not really bug. Thanks for the report anyway.

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Marker tracking erratic when used directly on video but perfect on imported image sequence of same video for stabilization purpose. #48551