If you are having issues with multiple framerates in a Premiere timeline--the best solution is to transcode ALL your footage to ONE FORMAT and ONE FRAMERATE. By doing this, you are eliminating so many issues and problems. Premiere is fantastic at mixing framerates--but there can be issues. Use the INGEST settings in Premiere to import all your footage into a single format or use Media Encoder by itself to encode BEFORE you edit. Most of us love Premiere for its ability to work natively with camera footage. Instantly import and edit in seconds! Premiere is the best editor in the world natively and I work with Avid and Final Cut professionally. Premiere has them both beat. This is all great--but the truth is, if you have the time and hard drive space, transcoding all your footage into a single format and framerate almost completely ensures the success of a project (how good or bad the original footage is another matter). In reference to one of your statements, it looks as if your bitrate is too high. If you are exporting your video for Youtube--as long as the video looks fine on your computer--Youtube should not reject it unless it is too big or the bitrate is too high. Even if you mix multiple video clips with different framerates--all will be converted to one framerate when you export to H.264. As stated previously, 150 Bitrate is too high. If you wanted a higher bitrate for a 1080P or 4K video--I would keep it within 8 to 45 Mbps. If you want a great video quality on Youtube--you have 2 choices. Use the official Adobe Youtube Presets (which are excellent: Youtube 1080P, Youtube 2160P,etc.) or high encode using a high bitrate. Once again, I would keep your bitrate below 50-70Mbps. We've used 40 to 45 quite a bit with great success. And, as a side note, Premiere + Media Encoder applications are some of the best in the world for encoding H.264. I use them daily for all levels of professional work. Just FYI--Here are the most recommended settings for Youtube now in 2018 (From Youtube's Website): Container: MP4 Audio codec: AAC-LC Channels: Stereo or Stereo + 5.1 Sample rate 96khz or 48khz Video codec: H.264 Progressive scan (no interlacing) High Profile Variable bitrate. No bitrate limit required, though we offer recommended bit rates below for reference Frame rate Content should be encoded and uploaded in the same frame rate it was recorded. Recommended video bitrates for SDR uploads To view new 4K uploads in 4K, use a browser or device that supports VP9. Type Video Bitrate, Standard Frame Rate (24, 25, 30) Video Bitrate, High Frame Rate (48, 50, 60) 2160p (4k) 35-45 Mbps 53-68 Mbps 1440p (2k) 16 Mbps 24 Mbps 1080p 8 Mbps 12 Mbps 720p 5 Mbps 7.5 Mbps 480p 2.5 Mbps 4 Mbps 360p 1 Mbps 1.5 Mbps Recommended video bitrates for HDR uploads Type Video Bitrate, Standard Frame Rate (24, 25, 30) Video Bitrate, High Frame Rate (48, 50, 60) 2160p (4k) 44-56 Mbps 66-85 Mbps 1440p (2k) 20 Mbps 30 Mbps 1080p 10 Mbps 15 Mbps 720p 6.5 Mbps 9.5 Mbps 480p Not supported Not supported 360p Not supported Not supported Recommended audio bitrates for uploads Type Audio Bitrate Mono 128 kbps Stereo 384 kbps 5.1 512 kbps ----------------------------------------------------------------------------------------------------
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