the vertical black bars on the outside of the screen, they need to be gone.
The problem is you have 4:3 content, and YouTube only offers a 16:9 player. That means you get black bars on the sides.
The real issue with your upload is that the black bars are not big enough. Your piece has been stretched out, distorting the image, but not all the way.
Go back to Premiere Pro and export again using a YouTube SD 480p preset. Do not choose Widescreen.
As has been stated, what you see is a mis-match of the Source Footage and the Project, plus a mis-match between the Source Footage, and YouTube's player.
There are a couple of options:
- Leave the black bars, and fix that footage that has been "stretched" to almost fill the Frame, as per Jim's suggestion.
- Create a Widescreen Project, and manage the black bars in another way. One would be to create a Color Matte, with some pleasing color, and basically add your 4:3 footage as a PiP (Picture in Picture), or create a pleasing abstract background, with the 4:3 material in a PiP.
- Create a Widescreen Project, Import the 4:3 footage into that, then Scale it up to fit the width, allowing the top and bottom to be effectively cropped. If one has artwork, those should be redone to match the 16:9 Project Frame. Note: with any Scaling, there will be some quality loss, but maybe not too much.
Many news networks, that have to handle 4:3 material, will do a PiP, for their Widescreen broadcasts. One trick is to Scale UP that Source Footage (quality loss will not be noticed, due to the next steps), "ghost" it back (usually with Levels, or similar to adjust both Contrast and Brightness), add a fairly heavy Blur, then drop the 4:3 material as a PiP. That ends up having the same footage in both the background, but with the ghosting and Blur in the "background," the PiP footage stands out very well.
Doing things like using Interpret Footage, to alter the PAR will result in "squeezing," or "stretching," and that will almost never look good.