H.264 export choppy

[Ivan Myles]

It is not a playback issue; the choppiness is caused by repeated frames encoded into the export file.

I went through the first ~1000 frames and only noticed an issue with the clip starting at f226. Because the other clips look fine, it does not appear to be an encoder issue. To check, import the H.264 output file into your project and insert it onto the timeline. Compare the repeated frames (e.g. f228-229, f230-231, f233-234) in the H.264 file to the source clip on the timeline. Are the same frames repeated in the original clip on the timeline?

The clip starting at f226 repeats in the following pattern:

ABCCDDEFFGHHIJJKLLMNNOPPQRRSTTU

One out of every three frames is a repeat frame. It looks like Premiere is trying to play a 20fps clip on a 30fps timeline. You said you slowed down the original footage. I think this clip went too far. Verify the source frame rate and make sure the you don’t slow it below 30fps. Otherwise, try using After Effects to create interpolated frames.

[Scott Talbot]

Hey thanks so much for the reply. I’m going to go in and check that stuff now. I do have a question about premiere and slowing down footage. For this project I was right clicking on the clips in the timeline and changing the “Speed/Duration…”. Is there better way to do this so that I can say like 24fps and it will play all the frames at that speed?

Thanks.

[Ivan Myles]

For this project I was right clicking on the clips in the timeline and changing the “Speed/Duration…”. Is there better way to do this…

There are a few different methods depending on what you are trying to accomplish:

Interpret Footage – always play a source file at a specified frame rate; all clips from the file will play at the new frame rate (unless modified as outlined below)
Speed/Duration – specify a unique frame rate for a clip on a timeline; does not affect other clips from the same source file
Time Remapping – Use keyframes to vary speed at different points within a clip; does not affect other clips from the same source file

…so that I can say like 24fps…

Slowing a clip to 24fps on a 30fps timeline will result in every 5th frame being a repeat:

ABCDDEFGHHIJKLLMNOPP…

This won’t be noticeable in static shots, but high motion and panning shots might appear to stutter. Take a look at creating interpolated frames in After Effects.

…and it will play all the frames at that speed?

Interpret Footage or Speed/Duration will work.

[Scott Talbot]

Hey thanks for the quick reply.

So I’ve been messing with stuff. I basically changed everything to either 100% speed or 40% speed. And I’m rendering at 24p.

Things seem to be fine in the preview but when I render, it will randomly just get choppy. For example a clip will be playing fine but then in the last 1/5 of it, it will get really choppy. And I’ve hit pause during the choppy parts and it looks interlaced…

I will try and post an example of my problem on vimeo tomorrow morning.

[Ivan Myles]

Repeat the process outlined above to troubleshoot. It is important to narrow down whether the issue is with playback, encoding, or on the timeline.

[Scott Talbot]

Okay so I brought it into VLC and went frame by frame because I couldn’t figure out how to do that in Premiere.

I’m uploading an example right now to show you, but basically the 5th clip in is set to 40% of 60fps. The project is rendered at 24fps. The clip starts fine but right at the end it starts cutting out every other frame. I know there is frame skipping because if you played the at 2x and it keeps the same panning speed.

For clarification there are clips with the same settings before this clip and they play fine. And this clip plays fine until the very end.

Thoughts?

[Scott Talbot]

Here is the vimeo example:

Password is “otis” again.

https://vimeo.com/59273174

[Ivan Myles]

I see what you mean. Starting at frame 801 every frame is repeated. Could you please post an H.264 version of the 5th clip source file at 60fps, and preferably all I-frame? I would like to try replicating the issue. Also, does the source clip look good when you view it on the 24fps timeline, or are frames repeated prior to encoding?

[Ivan Myles]

I just use the arrow keys to view frame by frame in Premiere.

[Scott Talbot]

Here is the original file. All I did was drag it in and set it to 40%

https://dl.dropbox.com/u/12914186/MVI_8259.MOV

I tried to do arrows but repeats frames all over. I think thats a preview rendering issue though. Whenever I hit render effects or render work area premiere crashes…