I figured I would go ahead and make this thread discussing my method of rendering video files in 720p HD since it can be confusing at times and Youtube will occasionally not accept an HD render. Basically this thread is just a tutorial on how to get good quality video up on youtube for anyone that wants to.
For Sony Vegas:
1. Make sure that any video you are importing into Vegas (to add audio or whatever) is already in an HD format (16:9 aspect ratio).
2. Set the composition size to 1440x720 pixels (the size that youtube is).
3. Right click the video footage you have and uncheck the maintain aspect ratio box.
4. File - Render As.
5. Under the 'Save As' drop down menu - select Sony AVC.
6. Beside the template box, click Custom.
7. Under the Project Tab, select Best.
8. Under the Video Tab, select custom. Then type enter 1440 and 720 in the boxes.
9. Under the Audio Tab, make sure the drop down box has 192kbps audio selected.
10. *Optional* In the Bit Rate box, type in the bit rate from the original video. (For example, if the video size is 10MB, you would put 10,000,000)
11. Render
For Adobe After Effects:
1. Make sure that the Composition is 1440x720.
2. After finishing, hit ctrl+shift+?. This will bring up the pre-render box down below. There will be a link that says
Lossless. Click this.
3. You should now see the output setting menu.
4. Click the format options box.
5. Choose XVID MPEG-4 Codec from the drop down list. (You might have to download and install it if you dont already have it).
6. Click Configure.
7. Drag the slider all the way to the left and click OK.
8. At the bottom of the output settings menu, there will be a checkbox for audio output. Make sure this is checked even if there is no audio.
9. Press Render
The above methods should result in 720p Youtube video 100% of the time. Hopefully this will be of assistance to many.