I have got an Video, which was shot with 1920x1080 and 25FPS. I imported the clips into Adobe Premiere Pro and exported them with the H.264 format and with the Youtube presettings (1920x1080 and 25FPS). In Youtube the video looks okay, also there are small black bars on top and on the bottom of the video. If i share and play the video through Facebook, there are big black bars on top and on bottom of the video. Before this i edited videos with the same setting with Adobe Premiere Elements and there was no such a problem. I also checked the sequenz setting, but they also seem to be alright. I can't change anything here, but they look exactly like the source video settings!
Does someone knows where the problem might be?
If using the pre-settings remember you have two options SD and HD. When selecting the HD option your export won't appear to be letter-boxed (black bars).
Letterbox means that a 16:9 widescreen video, played on a 4:3 display, has the black bars top and bottom. From my understanding 1920x1080 will give you bigger bars than if 720. If uploading to youtube or FB the black bars are pronounced even though the bars to appear on the file when viewing for example on your computer.
I can't really determine if the black bars you're getting are abnormal without a screenshot. But here is some detail info from Adobe on exporting. http://helpx.adobe.com/media-encoder/using/export-settings-reference.html#video_exports_settings