I add to the timeline 60i clip

I export using customized mp4 preset

I don't know about quicktime, can that affect?

Hi

Your export dialog box looks different to mine in MX - see difference where circled in the image below - are you using a different codec to the MainConcept one installed with MEP?

The export  presets are optimised for each format of video format and changing these can have a considerable detriment on the video quality.

What is the end purpose of the exported video?

Did you change the default settings to those shown above, and if so for what reason?

John

I have changed the parameters in order to get much better video rendering quality compared to original "optimized" settings. And I get much better. I watct the exported videos in computer screen and in Samsung smartTV. This choppy video is happening only sometimes and is dependent on where I cut the video. I have experiemented to cut the clip in different positions and sometimes the result is choppy and sometimes OK. Most often I don't cut form the beginning of the clip so the problem is not big.  I don't want to use the original "optimized" video settings because then the quality of original clips worsen too much.

Hi

Your biggest improvement in quality has likely come from the big increase of almost double the bit rate. Increasing the Bframes will raise compression and lower filesize and quality.

Reducing the GOP length could increase quality by reducing compression but only if there is a sufficiently high bitrate in the stream. It could also create the jerking problems you are having.

It is best to analyse the original camera clips with Media Info and stick to the original specifications for the advanced parameters like GOP, Bframes and Bitrate. Or, if you are only trimming the clips with no other cleaning or effects then use Smart Render or Smart Copy, which will preserve the original structure of the picture stream.

Have you tried "Rt.Click > Create New Frametable" BEFORE you do any editing? This helps in maintaining a correct GOP structure when editing.

Ss

Hi

In addition to Scenestealers comments- the optimum GOP setting for quality depends on the content of the video and the amount of movement / action.

For high action complex scenes the optimum GOP length will be shorter than for a tranquil slow moving scene.

For 60i video GOP setting should be around the 30 mark.

. . . . Create New Frametable" BEFORE you do any editing? . . . .

This should only be applied to Mpeg video.  H.264 does not use frametables and applying this setting can cause issues.

John

I tested to render to different  formats usiong predefined profiles (mp4, Wmv, mpeg2). All the time same problem, jump every one second.  So this is not dependent on rendering options. It must be something else.

The clip is actually 59.94i  ie. 29.97 interlaced.  If I render the program as 30 interlaced  (60i) I don't get the jup every one second. But the I get some small disturbance (several frames) every 16 seconds.

New info. The jump every one second is actually visible already in timeline, so it is nothing to do with rendering of final program.

Hi

I think the issue is the result of 'pulldown' when changing framerates.  As an aside, if you change from Interlaced to Progressive you add in a second problem.

. . . . The clip is actually 59.94i  ie. 29.97 interlaced.  If I render the program as 30 interlaced  (60i) I don't get the jup every one second. But the I get some small disturbance (several frames) every 16 seconds.. . . . .

That is a  problem I sometimes had when changing framerates of video from one of my sport cams (30fps) down to 25 fps.  It is caused by the pulldown where it, in effect,  'drops' one or more frames at regular intervals to produce the correct framerate.

Some cameras are designed to shoot in progressive mode at 24 fps and then record the video to storage as a 60-field interlaced signal.  If yours is doing this then the 'pulldown' algorithm in MEP may not be sophisticated enough to handle this correctly.

Can you upload a short length of original video ~10 - 20 seconds long from the Nikon to, for example Dropbox, and post the link for us to have a look at and see if we can reproduce the problem?  If we can then I would suggest contacting Magix support and ask them to have a look at the problem.

Thanks

John

[[VIDEO:cloud://]]

I uploaded one V1 video file here. Can you download it?

Hi

V1 video file is found here

https://www.dropbox.com/s/q6f0tf779ij5tip/DSC_6506.MOV?dl=0

Hi,

I downloaded and tried the file in MEP2015Premium. I don't have MX workable anymore.

I tried a couple of seconds from the front and back, now 08:29 long. Playback was fine.

I rendered the modified clip. Playback was fine, no jumps.

So maybe the problem is just in MEP MX?

Hi

I have also tested with both MX and 2015 and get the following:-

All tests at 1920x1080 using the MainConcept encoder in both NTSC and PAL fomats - appears export as NTSC or PAL makes no difference.

One observation I have made using MEP 2015 is that there is very strong interlace 'combing' - see image - present where there is rapid movement eg the first red car as it nears the camera - this is not visible in MX.

I have a strong suspicion the camera is actually recording as 30p and then processing the video to 60i.

Try shooting 1920 x 1080 30p and then exporting as before from MX.

HTH

John

Thanks for trying to help with this. I also tried with MEP201 demo version and it worked OK. 

In my MEP MX, the problem exist in all export formats, even with uncompressed avi, and in timeline.

It is dependent of the position of cut. It I try out different poits to cut I can find a cut that doesn't lead to jumpy video.

Hi All

My tests with MX confirms the following:-

Uncut clip - no problem in timeline or export.

Trim 2 sec 15fr - OK

Trim total 3sec 14fr - jerk 1:15 caused by duplication of frame 15 and occurring every second from there but at 4th sec. looks like 1/2 frame forward then 1fr. back.

Export at 59.94 P then problem still there but at double the amount of time and clip plays in slow motion!

MEP2014 - all above scenarios play correctly.

Conclusion - must be a problem with that type of footage, in MX, that was fixed in later versions of MEP and could be to do with the Video Readers (don't ask me what they are) that Support sometimes refers to.

An interesting problem and discussion though. Actually I can not get the original to play smoothly in any of my installed players WMP, VLC or QT. Exported footage is fine however. 

John

I have a strong suspicion the camera is actually recording as 30p and then processing the video to 60i.

I think you may be spot on with your observation as I this is probably more common than we might think, especially with cameras that are primarily set up for progressive capture of still frames. It is sometimes referred to as "PSF = Progressive Segmented Frames" where the chip scans two half frames progressively with the result that there is no offset when it is interlaced. I was suspicious when I could not see any combing with the original footage in MEP regardless of whether "Interlace processing" was turned off or on in MEP's Program settings. Also the fact that Media Info reports the footage as 59.94FPS is unusual for 29.97 Interlaced material which usually reports 29.97 as the frame rate.

Not sure why you see such dramatic combing in MEP2015 (which I do not have installed).

For high action complex scenes the optimum GOP length will be shorter than for a tranquil slow moving scene.

This will only be true if the bitrate is raised to accomodate the decreased compression that results from a shorter GOP.

H.264 does not use frametables

I am not sure this is true, and the fact that it causes problems if used after editing has been carried out on H264 material tends to indicate it is messing with the said Frametables.

Peter

thank you for your efforts. So one solution would be to upgrade to MEP 2015.

Also confirmation that interlaced vidoe is difficult to handle compared to progressive. 

However, I need to use Nikon V1 60i since it gives better image quality than 30p (sharper, better motion)

I took another look at the video file in MEP2015. The problem was almost unnoticeable until I used the arrow key to scroll across the timeline. I got the same type of images as John EB. Just thought I'd clarify that.