12 Oct Apple iOS Video Pipeline Experiment- Part 2
In my last post, I talked about my experiences with capturing video using my fourth generation iPod touch and getting that video into my iPad for use. Recording video with the iPod was easy. Getting the video from the iPod 4 to the iPad was painless, but there were trade-offs. So let’s look at the experience of working with the video on the iPad.
Video Stitching on the iPad
Now that I had the content on the iPad, it was time to turn all of the individual files into one single file, or movie. iMovie is available for the iPod, but not the iPad, so I used an app calledReelDirector ($3.99).
This process was straightforward. I gave the movie a name, changed the font to a more “pony-like” one, pressed “+”, and added the videos from the iPad’s Photo Roll. Each video went through a compression process which took a few minutes. I figure it was just putting it into a more workable format that was quick to edit. After I got all the videos into ReelDirector, I then surveyed the entire video to make sure I got everything right.
To turn it into one video I pressed the “Render” button. ReelDirector told me that it could take a long time. For the simple stitching it was very fast; it took only 4 minutes to render a 19 minute movie which it saved into the Photo Roll. Was this too good to be true? Yes, it was.
When I got back to the office and had a PC, I used QuickTime’s “Movie Inspector” to see the output video’s technical characteristics. Movie Inspector showed that the ReelDirector application compresses the 720p HD/10.53Mbps video to 360P/ 3.55Mbps. It was too good to be true.
So what does this mean? Well, in terms of the quality measured by the amount of pixels, this is a 75% decrease in the amount of pixels. In terms of bit rate this means a 66% decrease in bit rate. There are a lot of factors (i.e. screen size) that determine how this could impact the experience, but I will save that for the “Playback” section.
4 minutes to render 19 minutes of video was pretty good, but I know that the “downsampling” helped that. So would it be as fast when I started to get a little “fancier” with my video effects?
Well, the short answer is no. When I zoomed in on the first video in the series, that same 19 minute video took 33 minutes and 9% of the battery life. That’s an 8X increase over the video above. Adding audio or music really slowed it down, too.
Of note, I couldn’t do anything on the iPad when it was rendering. Not a big deal on a short video, but suboptimal with a large video. So, remembering that this test is designed to push the limitations of the devices, here are my pros and cons for using the iPad and ReelDirector.
- Fast when just stitching and adding titles.
- Inexpensive video rendering app at $3.99.
- Export to YouTube option.
- 720p HD video was reduced to 360p video, a 75% reduction in pixel count
- Rendering files with panning or zooming took a very long time and a lot of battery life. 8X longer than the standard file with no effects.
- Couldn’t use the iPad while movie was rendering.
- Only .mov file formats exported. Won’t play on many movie players or playback well on a Windows 7 or Vista PC without QuickTime.
- My iPad is pricey at $899.
I now had one single video file that my wife or I, or more importantly my daughters, could easily watch on the iPad and on the hotel HDTV.
The convenience of having highly portable devices for capturing and editing videos on the road was great, but there were tradeoffs. In my next blog, we will see if the video degradation matters and I’ll give my conclusions on the iPad and iPod as my portable video studio.
Let me know if you have found a solution that you find works well as your portable production house.