Because of missing information in your problem description, you will see me using "assume"....we can fine tune the "assume" with your
reply to the post that I am writing now.
For now I am assuming that your Premiere Elements 13 is on Windows 7, 8, or 8.1 64 bit. I will further assume that your
1920 x 1080 is @ 25 progressive frames per second.
a. Open Premiere Elements 13 to its Expert workspace.
b. Go to File Menu/New/Project and Change Settings
c. In Change Settings, set the project preset to
Close out of there. When you do, you will be greeted by the new project dialog with the new project preset setting.
Make sure that you have a check mark next to "Force Selected Project Settings on this Project" in that new project dialog.
Close out of there.
d. Back in the Expert workspace, import your 1920 x 1080 @ 25 progressive frames per second into the project using the project's
Add Media/Files and Folders/Project Assets. From Project Assets, drag the video to the Timeline Video Track 1/Audio Track 1.
e. Now import your 1280 x 720 @ 50 progressive frames per second.
Render the Timeline by pressing the Render button above the Timeline. After the
render is complete, what does the playback in the Edit area monitor look like video and audio quality wise? Are there going to
f. When you arrive at Publish+Share/Disc/Blu-ray disc, consider the reset = H.264 1920 x 1080i PAL Dolby.
What is the result when you play back your Premiere Elements 13 Blu-ray disc format on Blu-ray disc?
Any questions or need clarification, please do not hesitate to ask.
Add On...See if you can find out for me whether your 1920 x 1080 source is recorded at 25 interlaced or 25 progressive frames per second. Brand/model/settings of camera that recorded the video might give us the information needed. Right now I am assuming 1080p instead of 1080i.