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Microstock Footage Forum => General - Stock Video => Topic started by: superdone on January 26, 2016, 03:40

Title: Clip exhibits issues related to frame rate
Post by: superdone on January 26, 2016, 03:40
Hi all,

I have started to uploading videos for a few weeks. In particular SS accepted some videos and rejected some other ones for the following reason "Clip exhibits issues related to frame rate". The workflow and the settings are the same both for accepted videos and for rejected ones. They are basic HD clips at normal speed. I work with adobe premiere cs6.

I really don't know what does "Clip exhibits issues related to frame rate" mean so I ask for your help to try to fix the issue and to upload them again.

Can you kindly give some hints?
Title: Re: Clip exhibits issues related to frame rate
Post by: Mantis on January 26, 2016, 09:04
Are you outputting at 24fps but shooting at something higher? That can cause choppiness, hence a "frame rate"rejection.   
Title: Re: Clip exhibits issues related to frame rate
Post by: superdone on January 26, 2016, 09:53
Mantis, thanks a lot. I'll check it.
Title: Re: Clip exhibits issues related to frame rate
Post by: superdone on January 28, 2016, 19:47
Are you outputting at 24fps but shooting at something higher? That can cause choppiness, hence a "frame rate"rejection.

I checked it. I shooted at 50p (50 frame per seconds progressive mode) and I outputted at 25 frame per seconds
So how I can fix it? My camera permit me to shoot at 50i or 50p so I am obliged to opt for 50p. So I have to output at 50 frame per seconds? Am I right? I use premier pro cs6. Do I have to flag some options in exporting settings window???....for instance "Use Maximum render quality" or something else???

Thanks in advance
Title: Re: Clip exhibits issues related to frame rate
Post by: Mantis on January 28, 2016, 20:22
Are you outputting at 24fps but shooting at something higher? That can cause choppiness, hence a "frame rate"rejection.

I checked it. I shooted at 50p (50 frame per seconds progressive mode) and I outputted at 25 frame per seconds
So how I can fix it? My camera permit me to shoot at 50i or 50p so I am obliged to opt for 50p. So I have to output at 50 frame per seconds? Am I right? I use premier pro cs6. Do I have to flag some options in exporting settings window???....for instance "Use Maximum render quality" or something else???

Thanks in advance

I don't use Adobe Premier so I can't tell you how to conform, but I would try to create a project at 29.9 fps and conform to that, as it is a standard frame rate.  Are you trying to shoot for slower speeds? Going from 50 to 25 cuts down your speed.  Otherwise, why not submit at 50? Or set your camera to shoot at 29.9 fps. Conforming a video might do a better job of getting rid of super visible choppiness or jitters.
Title: Re: Clip exhibits issues related to frame rate
Post by: ACS on January 29, 2016, 02:32

I checked it. I shooted at 50p (50 frame per seconds progressive mode) and I outputted at 25 frame per seconds
So how I can fix it? My camera permit me to shoot at 50i or 50p so I am obliged to opt for 50p. So I have to output at 50 frame per seconds? Am I right? I use premier pro cs6. Do I have to flag some options in exporting settings window???....for instance "Use Maximum render quality" or something else???

Thanks in advance

You are doing right. Shooting at 50p and exporting at 25p is good to have smooth motion. Actually your actual frame rate should always be equal or double of your exporting frame rate.

What might have happened?

1) it was a low light scene, you shutter speed was below 1/25 secs although your recording fps was 50.

2) due to the nature of the scene it looks like as if it is choppy but actually it is not. It happened to me once when I submitted rain drops on window timelapse. The motion itself was choppy because of the wind pattern.

3) the reviewer hit the wrong button.

If it is not (1) try to resubmit.
Title: Re: Clip exhibits issues related to frame rate
Post by: superdone on January 29, 2016, 06:21

You are doing right. Shooting at 50p and exporting at 25p is good to have smooth motion. Actually your actual frame rate should always be equal or double of your exporting frame rate.

This is what I really wanted to know! Thanks a lot! ;)



Title: Re: Clip exhibits issues related to frame rate
Post by: PhotoLA on January 29, 2016, 14:48
Step through your rendered movie frame by frame and double check that there's no repeating frames. That's the biggest frame rate problem people have.
Title: Re: Clip exhibits issues related to frame rate
Post by: superdone on January 29, 2016, 17:30
Step through your rendered movie frame by frame and double check that there's no repeating frames. That's the biggest frame rate problem people have.

I didn't understand. And if I found a repeated frame, what should I do?
Title: Re: Clip exhibits issues related to frame rate
Post by: ACS on January 29, 2016, 18:13
Step through your rendered movie frame by frame and double check that there's no repeating frames. That's the biggest frame rate problem people have.

I didn't understand. And if I found a repeated frame, what should I do?

If you find any repeating frame, do not resubmit. It will be choppy. But it is a painfull process, if I were you I would invest my time creating new clips.

Some cameras, in S mode (shutter priority) allow you to shoot below 1/25 secs. Lets say you shoot at 1/10 secs and you are recording it at 50 frames per second. In this case your cam repeats each frame 5 times and this cause choppiness. And this happens especially in low light situations. Shoot at manual exposure mode, and keep your shutter speed value 1/25 or 1/50 or 1/100 etc. Never go below 1/25. These settings are fine for 50p mode and 25p export from Premiere.
Title: Re: Clip exhibits issues related to frame rate
Post by: superdone on January 29, 2016, 18:19
Shoot at manual exposure mode, and keep your shutter speed value 1/25 or 1/50 or 1/100 etc. Never go below 1/25. These settings are fine for 50p mode and 25p export from Premiere.

Thanks again for this hint!
Title: Re: Clip exhibits issues related to frame rate
Post by: PhotoLA on February 01, 2016, 19:40
Step through your rendered movie frame by frame and double check that there's no repeating frames. That's the biggest frame rate problem people have.

I didn't understand. And if I found a repeated frame, what should I do?

If you're on a Mac, you can open the movie that you're submitting in the Quicktime Player application. You can use the arrow keys to step frame by frame through your movie and see if you have repeating frames. I'm not sure what programs on the PC allow you to go frame by frame.

If you find repeat frames, then you're doing something wrong in your post processing.

Title: Re: Clip exhibits issues related to frame rate
Post by: superdone on February 02, 2016, 01:24
thanks!
Title: Re: Clip exhibits issues related to frame rate
Post by: superdone on February 16, 2016, 05:10
I still don't understand what is the problem. I got other videos rejected from SS for issues related to frame rate. In particular for two similar (basic) videos shot with the same camera, same lens, same session, same work flow, same subject.......one has been accepted and one has been rejected for issues related to frame rate  :(

   
Title: Re: Clip exhibits issues related to frame rate
Post by: superdone on February 19, 2016, 20:11
I asked for clarifications to SS staff and they kindly gave them (thanks SS staff!).

"the videos appeared to have ghosting because they are interlaced"

How can I check if my videos are interlaced? I would say no, but I want to be sure.

Do I have to look at exif data and make a comparison between shooted video and output video???
Title: Re: Clip exhibits issues related to frame rate
Post by: increasingdifficulty on March 02, 2016, 06:32

You are doing right. Shooting at 50p and exporting at 25p is good to have smooth motion. Actually your actual frame rate should always be equal or double of your exporting frame rate.

What might have happened?

1) it was a low light scene, you shutter speed was below 1/25 secs although your recording fps was 50.
...

Shooting at 50p and exporting at 25p is only good for smooth SLOW MOTION. If you want real time you will just delete every second frame if you export 25p.

If you want smooth motion for quick subjects in real time you need to export 50p.

Also, if you have a shutter speed of 1/25 when recording 50p every second frame will be a duplicate = no benefits at all. You should then shoot 25p, and only if the light is low and demands it. This doesn't even work on most cameras.

Unless you want slow motion, always shoot at the same settings you want to export.

If you shoot 50p the "correct" shutter speed would be 1/100th of a second, giving you too little motion blur if your intended output is 25p in real time.