Exported files pixelate

So, as I understand you, your HG20 is not a supported camera. Per my earlier post, that may be the cause of the problem.

In Finder, try control-clicking on the AVCHD folder and then click on Show Package Contents. In the package contents, in one of the folders, will be the MTS files that are the actual movie files. The MTS files are what need to be converted to an iMovie supported format. Option-drag (Copy, not move) them to your desktop, and then convert with Handbrake.

Take a look at this link and see if the procedure described there works for you:

https://bronami.video/avchd-files-extract-files/

-- Rich

Hi,

It could be a compression artifact or possibly some corruption in the clip.

Try sharing at High Quality, Better Quality Compression, and higher resolution if such an

option is available.

You also can try sharing in Best (pro res) if you don't mind a high file size.

Another thing you can try is to open the clip in QuickTime Player, and save to your desktop. You will get a .mov file. Drag that into iMovie and see if it plays properly.

-- Rich

You could experiment with various compression settings until you find one that doesn't cause compression artifacts in your shared project. I would reduce the resolution to 720 (or one level below the resolution in which the video was recorded). Reducing to 540 apparently was too big a jump. Use Handbrake to set the encoder as H.264 and the container as Mp4 if not already that. You can use Handbrake to reduce the audio quality if audio quality is not paramount. Or you could eliminate an unnecessary audio track.

Here's a You Tube vid that discusses some of this:

How to Reduce Video File Size Without Sacrificing Quality

-- Rich

What you see in the iMovie library should be exactly what came out of the camera. If you are seeing pixelation that was not there in the camera preview, then perhaps iMovie is not functioning properly or the clip is in a video format that iMovie doesn't support. What are the specs of your movie clip? Open it in Quicktime and click on Window/Show Movie Inspector. Take a screen shot of the inspector window and post it here.

What puzzles me is that iMovie exports it with no pixelation at 1080p.

Since it is a simple thing to do, you might try opening iMovie while holding down the Option and Command keys, and selecting to delete preferences in the box that appears. Sometimes that cures glitches. Also, I would update to High Sierra, because iMovie 10.1.8 (that I assume you are using) was designed for that operating system.

A practical consideration: Rather than fight it why not just use Final Cut Pro since it works there?

-- Rich

Your iMac Late 2009 can run High Sierra. You would need 2GB memory and 14.3 GB of available storage for the download.

macOS High Sierra - Technical Specifications

I was thinking more of your 2017 MacBook Pro.

As for the clip specs, they all look fine. Per my earlier post, for diagnostic purposes you can try using the free download, Handbrake, to convert the clip to Mp4/AAC, that Handbrake will do by default. Then see if that makes any difference. Also, try exporting from your camera to your desktop using the Image Capture app on your Mac. Then drag the movie into iMovie and see if that solves it. Possibly iMovie is not importing it properly with a direct import.

I didn't see your Canon HG20 listed in Apple's list of iMovie supported cameras. (There is a Canon HF G20, so maybe your post had a typo.) Perhaps that's the problem. If it's a tape based camera, it could still be supported even though not specifically listed. Here's the list in case I missed your camera:

iMovie supported cameras - Apple Support

At the start of this I was of the opinion that it was a compression artifact. But since it pixelates in the iMovie library, before share-out compression, then that likely is not the cause. At this point I am out of ideas as to what may be causing the issue.

-- Rich

File size and quality are always a trade off. iMovie has compression and bitrate adjustment capabilities to deal with it on a consumer level. You can choose higher or lower resolution, higher or lower bitrate, faster or better compression. To build in the professional converter and audio editing capabilities of specialty apps, though, would be beyond the pale of a free consumer app I would think.

-- Rich

Thanks for the info re iMovie converting MTS files.

Cheers,

-- Rich

Looks like we had the right workaround but just needed to find the correct converter for your camera. Interesting that FCP converts the MTS files. I'll remember that in case someone else reports your issue and also has FCP on their computer. iMovie used to convert the MTS files but doesn't in recent iterations.

Did the MTS files that you converted with Handbrake play without pixelation?

BTW, you can do batch conversions in Handbrake by adding them to queue. You don't need to do them one at a time.

-- Rich