Working with H.265 - The Art of Transcoding

Posted by Kerry 12/27/2016 3 Comment(s) Tips and Tricks,

The DJI Phantom 4 Pro and DJI Inspire 2 have seriously raised the bar for video quality in a ready-to-fly aerial camera platform. With 20 megapixel sensors, variable aperture, and mechanical shutters, these new systems are "real" cameras and can deliver professional quality results. The challenge is to get the most out of the capabilities of the cameras without sacrificing any quality along the way. One new feature of these new systems is the ability to record in H.265. The big advantage of H.265 is that there is about 50% more data being saved over H.264 while still maintaining about the same file size.

While H.265 is preserving more data and thus, can deliever better image quality, none of the top editors (Adobe Premeire Pro / Apple Final Cut X) can edit H.265 files well. To get either package to smoothly edit the H.265 files, we need to transcode (convert) them to something more usable. For our goal of maintaining maximum image quality while providing the smoothest editing experience, we will want to transcode the source files into ProRes 422 LT. While there are higher quality versions of ProRes, they will only cause unneccesary larger files and ProRes 422 LT can handle just slightly more data than we are generating, thus making it a great fit for our use.

The Tools

The two tools we are going to put to the test and considered to be the best ones available:

PavTube $35 (http://www.pavtube.com)
Available for both Mac and Windows

EditReady $49.99 (http://www.divergentmedia.com/editready)
Available for Mac systems

Our test setup was a 494.7mb H.265 file created from a DJI Phantom 4. The computer system was a 2013 MacBook Pro with the source file on an external USB hard drive and saving the converted file to the MacBook's internal SSD drive. Newer systems should result in faster conversion times but we felt this was a pretty middle-of-the-road test setup.

The Results

PavTube
Conversion Time: 5:53
Converted Filesize: 1,893,572,353 bytes (1.89 GB on disk)

EditReady
Conversion Time: 3:30
Converted Filesize: 1,890,698,876 bytes (1.89 GB on disk)

As you can see, EditReady clearly was significantly faster on the transcoding process. We didn't expect there to be any really noticable difference in file size and the difference is pretty trivial.

Why ProRes?

So why did we transcode to ProRes and not H.264? There are two main reasons why we chose the workflow we did. First, going from H.265 to H.264 is going to result in higher compression. Think of this like shooting a photo in DNG and then converting it to a JPEG before editing it. You are going to lose more image quality along the path. Secondly, once you import the H.264 into either editing system, you will STILL need to transcode it to something that is more editable, so going from H.265 to H.264, and then transcoding again, it simply a waste of time and quality. Going from H.265 to ProRes and then immediately being able to edit will save time and preserve as much quality as possible.

The Result

After editing in Final Cut Pro X, the final project was then exported as H.264 for upload to YouTube. Since YouTube is going to do some of it's own compression, the better the quality of the video we upload, the better the final result will be. Below is the fully finished video:

 

3 Comment(s)

Thure Wikberg:
12/27/2016, 12:27:12 PM
Reply

Great picture quality.

Nick Tucker:
12/27/2016, 01:03:43 PM
Reply

FWIW Premiere Pro now supports H.265 but it takes a lot of hardware to run smoothly.

Sam Armstrong:
12/31/2016, 06:28:08 PM
Reply

thanks for the explanation. Just got my P4P drone and spent the first 2 weeks mystified on how to even SEE the video. I can now see there's much to learn. thanks much Sam

Leave a Comment