I recently received my GoPro HD Hero camera. I wanted it to start doing some in car filming at the track. I did a few test clips at 1280 x 720 resolution. I then imported them into NeoScene. When I compare the outputted files to that of my Canon 5D Mark II, the GoPro files seem to get bloated a bit more than the 5DM2 ones. Not to mention, I was shooting 1080p on the 5D Mark II and only 720p on the GoPro Hero HD.

Examples: (resolution, clip time, original file size, converted file size, ratio)

5D Mark II
1920x1080, 00:24, 124 MB, 391 MB, 3.15:1
1920x1080, 00:12, 63.2 MB, 179 MB, 2.8:1
1920x1080, 03:03, 929 MB, 2.44 GB, 2.62:1

GoPro Hero HD
1280x720, 00:39, 38.6 MB, 222 MB, 5.75:1
1280x720, 00:14, 14.3 MB, 69.9 MB, 4.88:1
1280x720, 04:41, 272MB, 1.72 GB, 6.32:1

that is normal. 5DM2 file are I-frame compression, no temporal redundancy to around 40Mb/s. Most other H264 cameras use temporal compression to achieve high compression rates, in this case to around 7.5Mb/s. For 1080p CineForm averages 100-120Mb/s (2.5-3 times the 5DM2 data rate.) For that you get more precision, more color accuracy and more speed.

So does that explain why the GoPro videos that I run through NeoScene have a higher compression ratio than the 5D Mark II run through NeoScene? Seems odd, but I'm not a video guy.

Yes, totally explains it. Canon is 5D is 18:1 compressed (vs 4:2:0 1080) and the GoPro is 44:1 compressed. CineForm is between 6 an 9:1, not matter which source you use.

I have a GoPro Hero HD on the way. I am planning to use it mixed with 5D clips using Prospect. Curious what settings work the best. I was planning on the 1080p setting.

^^

Just stick with the 1080p settings. The only downside to the camera at this point is that the upside down feature is not in place. Therefore if you have the camera upside down, the video will stay that way. You will have to do the vertical and horizontal flip in post. I asked GoPro about that and they said it will be included in the first firmware update.

Only thing I would caution is that that the video will be no where near as good as the 5D Mark II.