In addition to the correct advice given, reducing the resolution (pixel dimensions) will allow the same relative quality by reducing bitrate in proportion to the pixel area..
Example:
8Mbs at 1280x720
2Mbs at 640x360
These are the same encoding quality, relative to the new size.
Mainconcepts AVC/AAC (mp4) template with the folowing render settings (custom): 1280 x 720, profile: main, frame rate: 29.97, Field order: progressive, PAR: 1, Num. of ref. frames: 2, check Use deblocking filter, Variable bit rate with 2 pass, Maximum (bps): 8,000,000 and average: 5,000,000
My videos are all under 15 min. and end up being between 400 to 500MB.
I need to start uploading to a video sharing site that has a 100MB size limit. I have tried compressing one of the videos I have and it was horrible in quality.
What settings would give me a quality file that is under 100MB? Also, should I use these new settings and run a render of the original file from my camera or use the .mp4?
You need to revisit the two answers already given and do the math. Really, that's all there is, no mystery.
What you are asking for is 15 minutes of 1280x720 HD at ~1Mbs. I can promise you, you won't like the result. Likely no one else will either.
If you reduce your pixel dimensions to 640x360, you "might" get acceptable quality at 1 to 1.5Mbs ABR.
You are also welcome to try Handbrake, which many of the pros here say works better at very low bitrates. But quality vs. file size is always relative to time, bitrate, and real estate. No getting around it.
Ok, I think I have a better idea. How can I just chop the original video into a smaller size and put a end cap on it saying "to continue viewing video please visit...."
Will I have to re-render the video to produce the shortened version?
Yes, that's the beauty of long GOP p- and b-frames and VBR. I can take full res 1920x1080 HD with no motion (just my grayscale charts) and render it out at 50Kbs at visually lossless quality. But that's not the real world where there are lighting, motion, and color variants.
But that doesn't diminish my appreciation for your results, which are indeed remarkable.
;?)