[Kdenlive-devel] Problem: Brightness changing when using still frames

[Claus R. F. Overbeck]

Hi,

I have a problem with inserting still frames in a video. The brightness
of the frozen/still frame changes compared to the rest of the video.
What I do is: Extract a frame from a clip. Than insert that frame as a
still. The same happens when I use the original clip and the freeze
effect. One can see this in the project preview but also in the rendered
video. My problem seems to be very similar to this:
https://forum.kde.org/viewtopic.php?f=270&t=116531&sid=1ae1f924705dcf0755177a39731fea19

I have placed a test project, that shows the issue, at
http://overbeck-it.de/tmp/kdenlive-test.tgz
When you play the project you can see changes in brightness. It also
occurs in the rendered output.

Is this a known issue and is there a workaround?
I am trying to finish an urgent project and would hate to have to switch
to a different software now but I really cannot live with the "blinking".

Thanks for your help!

Claus

P.S.: I love kdenlive, thanks for the great work!

[Dan Dennedy]

On Wed, Feb 19, 2014 at 7:28 AM, Claus R. F. Overbeck

Post by Claus R. F. Overbeck
Hi,
I have a problem with inserting still frames in a video. The brightness
of the frozen/still frame changes compared to the rest of the video.
What I do is: Extract a frame from a clip. Than insert that frame as a
still. The same happens when I use the original clip and the freeze
effect. One can see this in the project preview but also in the rendered
https://forum.kde.org/viewtopic.php?f=270&t=116531&sid=1ae1f924705dcf0755177a39731fea19
I have placed a test project, that shows the issue, at
http://overbeck-it.de/tmp/kdenlive-test.tgz
When you play the project you can see changes in brightness. It also
occurs in the rendered output.
Is this a known issue and is there a workaround?
I am trying to finish an urgent project and would hate to have to switch
to a different software now but I really cannot live with the "blinking".
Thanks for your help!
Claus
P.S.: I love kdenlive, thanks for the great work!

I do not have time to test this now, but please take a look at this
bug, which might be related:

http://sourceforge.net/p/mlt/bugs/204/

And here is a current 64-bit build you can test that includes the bug fix:

http://builds.meltytech.com/kdenlive/kdenlive-ubuntu12.04-x86_64-20140215.tar.bz2

P.S. You did not say anything about your OS and versions.

[Claus R. F. Overbeck]

Post by Dan Dennedy
http://builds.meltytech.com/kdenlive/kdenlive-ubuntu12.04-x86_64-20140215.tar.bz2

I use debian with kdenlive 0.9.6

and

$ dpkg -l |grep -i mlt
ii libmlt++3:i386 1:0.8.8-dmo1
i386 MLT multimedia framework C++ wrapper (runtime)
ii libmlt-data 1:0.8.8-dmo1
all multimedia framework (data)
rc libmlt3 1:0.6.2-0.0
i386 multimedia framework (runtime)
ii libmlt5:i386 1:0.8.8-dmo1
i386 multimedia framework (runtime)
ii libsmltk0 3.4.0.16.7-1
i386 library for SyncML-DS (SyncML Data Sync) clients
(shared libraries)
ii libxmltok1 1.2-3
i386 XML Parser Toolkit, runtime libraries
ii python-mlt5 1:0.8.8-dmo1
i386 multimedia framework (python bindings)


If you can provide a 32bit build I will test it! Does that build include
MLT?

Yours Claus

[Dan Dennedy]

On Wed, Feb 19, 2014 at 9:32 AM, Claus R. F. Overbeck

Post by Claus R. F. Overbeck

Post by Dan Dennedy
http://builds.meltytech.com/kdenlive/kdenlive-ubuntu12.04-x86_64-20140215.tar.bz2

I use debian with kdenlive 0.9.6
and
$ dpkg -l |grep -i mlt
ii libmlt++3:i386 1:0.8.8-dmo1
i386 MLT multimedia framework C++ wrapper (runtime)
ii libmlt-data 1:0.8.8-dmo1
all multimedia framework (data)
rc libmlt3 1:0.6.2-0.0
i386 multimedia framework (runtime)
ii libmlt5:i386 1:0.8.8-dmo1
i386 multimedia framework (runtime)
ii libsmltk0 3.4.0.16.7-1
i386 library for SyncML-DS (SyncML Data Sync) clients
(shared libraries)
ii libxmltok1 1.2-3
i386 XML Parser Toolkit, runtime libraries
ii python-mlt5 1:0.8.8-dmo1
i386 multimedia framework (python bindings)
If you can provide a 32bit build I will test it!

Here is today's 32-bit version. I do not recall if it runs on Debian
stable. I think it might depend on a newer glibc such that it will
work on Debian testing or unstable tho. Well, you can try:

http://builds.meltytech.com/kdenlive/kdenlive-ubuntu12.04-x86-20140219.tar.bz2

Post by Claus R. F. Overbeck
Does that build include MLT?

Yes, and x264, lame, frei0r, and FFmpeg. :o) You do not need to
install this. You simply extract it anywhere you like and run the
start-kdenlive script. You must use this launch script and not try to
run the binary in bin/ directly!

[Claus R. F. Overbeck]

Post by Dan Dennedy
Here is today's 32-bit version. I do not recall if it runs on Debian
stable. I think it might depend on a newer glibc such that it will
http://builds.meltytech.com/kdenlive/kdenlive-ubuntu12.04-x86-20140219.tar.bz2

Post by Claus R. F. Overbeck
Does that build include MLT?

Yes, and x264, lame, frei0r, and FFmpeg. :o) You do not need to
install this. You simply extract it anywhere you like and run the
start-kdenlive script. You must use this launch script and not try to
run the binary in bin/ directly!

Hi Dan,

thanks for the build. It runs on my debian (which has some packets from
testing and unstable).

However the problem persists. Could you check my project
(http://overbeck-it.de/tmp/kdenlive-test.tgz)? The error is easily
reproduced:
Open 00038_53.MTS in the clip monitor.
1. Extract some frame from the middle to a PNG and add this to the project.
2. Add the png to the timeline (track1)
2. Add 00038_53.MTS to the timeline (track2)
The change in brightness can be easily seen on the switch from track 1
to track 2

The same goes for overlapping 00038_53.MTS with a frozen version of
00038_53.MTS.

I really appreciate your help!

Claus

[Dan Dennedy]

On Wed, Feb 19, 2014 at 12:05 PM, Claus R. F. Overbeck

Post by Claus R. F. Overbeck

Post by Dan Dennedy
Here is today's 32-bit version. I do not recall if it runs on Debian
stable. I think it might depend on a newer glibc such that it will
http://builds.meltytech.com/kdenlive/kdenlive-ubuntu12.04-x86-20140219.tar.bz2

Post by Claus R. F. Overbeck
Does that build include MLT?

Yes, and x264, lame, frei0r, and FFmpeg. :o) You do not need to
install this. You simply extract it anywhere you like and run the
start-kdenlive script. You must use this launch script and not try to
run the binary in bin/ directly!

Hi Dan,
thanks for the build. It runs on my debian (which has some packets from
testing and unstable).
However the problem persists. Could you check my project
(http://overbeck-it.de/tmp/kdenlive-test.tgz)? The error is easily
Open 00038_53.MTS in the clip monitor.
1. Extract some frame from the middle to a PNG and add this to the project.
2. Add the png to the timeline (track1)
2. Add 00038_53.MTS to the timeline (track2)
The change in brightness can be easily seen on the switch from track 1
to track 2
The same goes for overlapping 00038_53.MTS with a frozen version of
00038_53.MTS.

I am not able to look into this for a while. I suggest you adjust the
brightness to at least make it close. There are a few adjustment
effects you can try to use.

[Dan Dennedy]

On Wed, Feb 19, 2014 at 12:05 PM, Claus R. F. Overbeck

Post by Claus R. F. Overbeck

Post by Dan Dennedy
Here is today's 32-bit version. I do not recall if it runs on Debian
stable. I think it might depend on a newer glibc such that it will
http://builds.meltytech.com/kdenlive/kdenlive-ubuntu12.04-x86-20140219.tar.bz2

Post by Claus R. F. Overbeck
Does that build include MLT?

Yes, and x264, lame, frei0r, and FFmpeg. :o) You do not need to
install this. You simply extract it anywhere you like and run the
start-kdenlive script. You must use this launch script and not try to
run the binary in bin/ directly!

Hi Dan,
thanks for the build. It runs on my debian (which has some packets from
testing and unstable).
However the problem persists. Could you check my project
(http://overbeck-it.de/tmp/kdenlive-test.tgz)? The error is easily
Open 00038_53.MTS in the clip monitor.
1. Extract some frame from the middle to a PNG and add this to the project.
2. Add the png to the timeline (track1)
2. Add 00038_53.MTS to the timeline (track2)
The change in brightness can be easily seen on the switch from track 1
to track 2
The same goes for overlapping 00038_53.MTS with a frozen version of
00038_53.MTS.

Claus, I started looking into this. I do not have a fix yet, but it
looks like a workaround (with the build I provided) is to make the
project use the ITU-R 601 colorspace. You will need to create a custom
project profile under Settings, switch the project to it using Project

Post by Claus R. F. Overbeck
Project Settings, and save (Save As?) the project. I recommend you

restart Kdenlive after that and load the new project. Hope that helps
for now.

[Dan Dennedy]

Post by Dan Dennedy
On Wed, Feb 19, 2014 at 12:05 PM, Claus R. F. Overbeck

Post by Claus R. F. Overbeck

Post by Dan Dennedy
Here is today's 32-bit version. I do not recall if it runs on Debian
stable. I think it might depend on a newer glibc such that it will
http://builds.meltytech.com/kdenlive/kdenlive-ubuntu12.04-x86-20140219.tar.bz2

Post by Claus R. F. Overbeck
Does that build include MLT?

Yes, and x264, lame, frei0r, and FFmpeg. :o) You do not need to
install this. You simply extract it anywhere you like and run the
start-kdenlive script. You must use this launch script and not try to
run the binary in bin/ directly!

Hi Dan,
thanks for the build. It runs on my debian (which has some packets from
testing and unstable).
However the problem persists. Could you check my project
(http://overbeck-it.de/tmp/kdenlive-test.tgz)? The error is easily
Open 00038_53.MTS in the clip monitor.
1. Extract some frame from the middle to a PNG and add this to the project.
2. Add the png to the timeline (track1)
2. Add 00038_53.MTS to the timeline (track2)
The change in brightness can be easily seen on the switch from track 1
to track 2
The same goes for overlapping 00038_53.MTS with a frozen version of
00038_53.MTS.

Claus, I started looking into this. I do not have a fix yet, but it
looks like a workaround (with the build I provided) is to make the
project use the ITU-R 601 colorspace. You will need to create a custom
project profile under Settings, switch the project to it using Project

Post by Claus R. F. Overbeck
Project Settings, and save (Save As?) the project. I recommend you

restart Kdenlive after that and load the new project. Hope that helps
for now.

OK, I found and fixed the bug. When the project called for an ITU 709
YCbCr colorspace, MLT also requested that colorspace for the RGB side
of a YCbCr-to-RGB conversion. But, libswscale in FFmpeg needed the
default 601-based coefficients.

Now, I want to warn you about an unresolved problem using the freeze
effect in Kdenlive preview. You see, Kdenlive via MLT uses SDL for
video playback. Normally, during playback, it is using YCbCr, but when
paused it switches to RGB mode. When you switch back and forth between
paused scrubbing/stepping over the freeze and playing through it
several times, it causes the "frozen" frame within the effect to
render between RGB and YCbCr respectively. There are slight
inaccuracies in the YCbCr<->RGB conversions that will accumulate on
the frozen frame's image each time you do this. This is not a problem
when you Render as it makes one pass through the freeze effect using
the same image format throughout, but it will manifest in the preview
depending upon how often you review the effect in different modes.

By mid-day Thursday, you can get a new build:

http://builds.meltytech.com/kdenlive/kdenlive-ubuntu12.04-x86-20140220.tar.bz2

[Claus R. F. Overbeck]

Hi List,

Dan fixed the problem mentioned below for me in the beginning of the
year. Now I have a new computer, I got Ubuntu 14.04 on it and installed
the recent kdenlive version from the ppa. And now the initial problem
returned. Didn't the fix make it into the new kdenlive version?

Any help on how to fix the blinking is appreciated.

Thanks
Claus

Post by Dan Dennedy

Post by Dan Dennedy
On Wed, Feb 19, 2014 at 12:05 PM, Claus R. F. Overbeck

Post by Claus R. F. Overbeck

Post by Dan Dennedy
Here is today's 32-bit version. I do not recall if it runs on Debian
stable. I think it might depend on a newer glibc such that it will
http://builds.meltytech.com/kdenlive/kdenlive-ubuntu12.04-x86-20140219.tar.bz2

Post by Claus R. F. Overbeck
Does that build include MLT?

Yes, and x264, lame, frei0r, and FFmpeg. :o) You do not need to
install this. You simply extract it anywhere you like and run the
start-kdenlive script. You must use this launch script and not try to
run the binary in bin/ directly!

Hi Dan,
thanks for the build. It runs on my debian (which has some packets from
testing and unstable).
However the problem persists. Could you check my project
(http://overbeck-it.de/tmp/kdenlive-test.tgz)? The error is easily
Open 00038_53.MTS in the clip monitor.
1. Extract some frame from the middle to a PNG and add this to the project.
2. Add the png to the timeline (track1)
2. Add 00038_53.MTS to the timeline (track2)
The change in brightness can be easily seen on the switch from track 1
to track 2
The same goes for overlapping 00038_53.MTS with a frozen version of
00038_53.MTS.

Claus, I started looking into this. I do not have a fix yet, but it
looks like a workaround (with the build I provided) is to make the
project use the ITU-R 601 colorspace. You will need to create a custom
project profile under Settings, switch the project to it using Project

Post by Claus R. F. Overbeck
Project Settings, and save (Save As?) the project. I recommend you

restart Kdenlive after that and load the new project. Hope that helps
for now.

OK, I found and fixed the bug. When the project called for an ITU 709
YCbCr colorspace, MLT also requested that colorspace for the RGB side
of a YCbCr-to-RGB conversion. But, libswscale in FFmpeg needed the
default 601-based coefficients.
Now, I want to warn you about an unresolved problem using the freeze
effect in Kdenlive preview. You see, Kdenlive via MLT uses SDL for
video playback. Normally, during playback, it is using YCbCr, but when
paused it switches to RGB mode. When you switch back and forth between
paused scrubbing/stepping over the freeze and playing through it
several times, it causes the "frozen" frame within the effect to
render between RGB and YCbCr respectively. There are slight
inaccuracies in the YCbCr<->RGB conversions that will accumulate on
the frozen frame's image each time you do this. This is not a problem
when you Render as it makes one pass through the freeze effect using
the same image format throughout, but it will manifest in the preview
depending upon how often you review the effect in different modes.
http://builds.meltytech.com/kdenlive/kdenlive-ubuntu12.04-x86-20140220.tar.bz2

--
Claus R. F. Overbeck
Geschäftsführer

Abovo-IT UG (haftungsbeschränkt)
Zeisigweg 41
52146 Würselen
Germany

Geschäftsführer: Claus R. F. Overbeck
Phone: [phone]
Amtsgericht Aachen HRB 18473
USt.-IdNr.: DE291391750

[Steve Guilford]

Are you referring to this problem?

Post by Claus R. F. Overbeck
However the problem persists. Could you check my project
(http://overbeck-it.de/tmp/kdenlive-test.tgz)? The error is easily
Open 00038_53.MTS in the clip monitor.
1. Extract some frame from the middle to a PNG and add this to the project.
2. Add the png to the timeline (track1)
2. Add 00038_53.MTS to the timeline (track2)
The change in brightness can be easily seen on the switch from track 1
to track 2
The same goes for overlapping 00038_53.MTS with a frozen version of
00038_53.MTS.

[Claus R. F. Overbeck]

Post by Steve Guilford
Are you referring to this problem?

Post by Claus R. F. Overbeck
However the problem persists. Could you check my project
(http://overbeck-it.de/tmp/kdenlive-test.tgz)? The error is easily
Open 00038_53.MTS in the clip monitor.
1. Extract some frame from the middle to a PNG and add this to the project.
2. Add the png to the timeline (track1)
2. Add 00038_53.MTS to the timeline (track2)
The change in brightness can be easily seen on the switch from track 1
to track 2
The same goes for overlapping 00038_53.MTS with a frozen version of
00038_53.MTS.

Yes. I get a change in brightness on the transition from a still
"frozen" frame to the moving picture.

[Brian Matherly]

This is the commit for the fix (Feb 20):
https://github.com/mltframework/mlt/commit/4fd6c14958ac5bd739c8d2b66b86cbf99ae68c23

It was released in MLT 0.90 (June 2):
https://github.com/mltframework/mlt/releases/tag/v0.9.0

The sunab kdenlive-release PPA has MLT versions for both 0.90 and 0.88:
https://launchpad.net/~sunab/+archive/ubuntu/kdenlive-release
The 0.90 build has a date of May 20. I'm not sure how that works out.

Minimally, make sure that your installed MLT version is 0.90 or newer.

Or use the latest daily build:

http://builds.meltytech.com/kdenlive/latest.rss


Or use the latest unstable build from sunab:
https://launchpad.net/~sunab/+archive/ubuntu/kdenlive-svn


~BM



________________________________
From: Claus R. F. Overbeck <***@abovo-it.com>
To: For kdenlive developers <kdenlive-***@lists.sourceforge.net>
Sent: Wednesday, September 17, 2014 10:44 AM
Subject: Re: [Kdenlive-devel] Problem: Brightness changing when using still frames

Post by Steve Guilford
Are you referring to this problem?

Post by Claus R. F. Overbeck
However the problem persists. Could you check my project
(http://overbeck-it.de/tmp/kdenlive-test.tgz)? The error is easily
Open 00038_53.MTS in the clip monitor.
1. Extract some frame from the middle to a PNG and add this to the project.
2. Add the png to the timeline (track1)
2. Add 00038_53.MTS to the timeline (track2)
The change in brightness can be easily seen on the switch from track 1
to track 2
The same goes for overlapping 00038_53.MTS with a frozen version of
00038_53.MTS.

Yes. I get a change in brightness on the transition from a still
"frozen" frame to the moving pictur

[Claus R. F. Overbeck]

Post by Brian Matherly
Minimally, make sure that your installed MLT version is 0.90 or newer.

I got 0.9.0-3 :

dpkg -l | grep -i mlt
ii libmlt++3 0.9.0-3 amd64 MLT multimedia framework C++
wrapper (runtime)
ii libmlt-data 0.9.0-3 all multimedia framework (data)
ii libmlt6 0.9.0-3 amd64 multimedia framework (runtime)



Claus
--
Claus R. F. Overbeck
Geschäftsführer

Abovo-IT UG (haftungsbeschränkt)
Zeisigweg 41
52146 Würselen
Germany

Geschäftsführer: Claus R. F. Overbeck
Phone: [phone]
Amtsgericht Aachen HRB 18473
USt.-IdNr.: DE291391750

[Brian Matherly]

Post by Claus R. F. Overbeck

Post by Brian Matherly
Minimally, make sure that your installed MLT version is 0.90 or newer.

dpkg -l | grep -i mlt
ii libmlt++3 0.9.0-3 amd64 MLT multimedia framework C++
wrapper (runtime)
ii libmlt-data 0.9.0-3 all multimedia framework (data)
ii libmlt6 0.9.0-3 amd64 multimedia framework (runtime)

My next piece of advice would be to try the daily build or the unstable package. Maybe there is something wrong with the sunab 0.90 package (I have some suspicion since the date was wrong).

~Brian

[Claus R. F. Overbeck]

Post by Brian Matherly

Post by Claus R. F. Overbeck

Post by Brian Matherly
Minimally, make sure that your installed MLT version is 0.90 or newer.

dpkg -l | grep -i mlt
ii libmlt++3 0.9.0-3 amd64 MLT multimedia framework C++
wrapper (runtime)
ii libmlt-data 0.9.0-3 all multimedia framework (data)
ii libmlt6 0.9.0-3 amd64 multimedia framework (runtime)

My next piece of advice would be to try the daily build or the unstable
package. Maybe there is something wrong with the sunab 0.90 package (I
have some suspicion since the date was wrong).

Hi Brian,

thanks for your help!
The problem seems to be fixed in the latest daily build!

Claus
--
Claus R. F. Overbeck
Geschäftsführer

Abovo-IT UG (haftungsbeschränkt)
Zeisigweg 41
52146 Würselen
Germany

Geschäftsführer: Claus R. F. Overbeck
Phone: [phone]
Amtsgericht Aachen HRB 18473
USt.-IdNr.: DE291391750

[Claus R. F. Overbeck]

Post by Dan Dennedy
Claus, I started looking into this. I do not have a fix yet, but it
looks like a workaround (with the build I provided) is to make the
project use the ITU-R 601 colorspace. You will need to create a custom
project profile under Settings, switch the project to it using Project

Post by Claus R. F. Overbeck
Project Settings, and save (Save As?) the project. I recommend you

restart Kdenlive after that and load the new project. Hope that helps
for now.

THANK YOU! Thank you for taking the time to look into this!

This works, the blinking is gone and I am a really happy user :-)

As I am no expert on colorspaces (I know what they are, but not all the
details and implications): Is there any downside to using this workaround?

Thanks!

Claus

[Steinar H. Gunderson]

Post by Claus R. F. Overbeck
As I am no expert on colorspaces (I know what they are, but not all the
details and implications): Is there any downside to using this workaround?

Yes; your colors will be subtly off if you show them on anything that expects
Rec. 709 or sRGB primaries, which means almost any modern HDTV or computer
monitor (although YMMV here, especially if your project is not in HD to begin
with).

/* Steinar */