[Ivan Myles]

Consider using JPG2000 at max quality for lossless image sequences in 8-bit RGB. I prefer 10-bit DPX to minimize RGB-to-YCC artifacts.

[Ivan Myles]

At 150% speed (1.5x faster) the new frame rate would be 90fps.
At 150% duration (1.5x longer) it becomes 40fps.

Note that neither of these rates is standard. At 150% speed you could reinterpret the footage to 90fps and then insert it into a 30fps sequence for export. As a result, every third frame will be used and the video will play at 150% speed. Alternatively, if you want the output to be 60fps use After Effects to interpolate every second and third frame into a new frame.

[Ivan Myles]

What is the format of the lossless file? Is there a lot of motion in the shot?

Here are a few things to try:

– In the Multiplexer tab be sure MP4 Stream Compatibility is set to Standard.
– In the Video tab select: H.264 format; Level 4.1; High Profile; VBR, 2-Pass; 20 Mbps target bitrate; 40-62.5 maximum bitrate; key frame distance set to half of frame rate; enable Maximum Render Quality

Also: What is the frame rate? 20 Mbps is plenty for 24-30fps, but might not be sufficient at 60fps.

[Ivan Myles]

I agree with Craig’s points. As an extension of his comments, I see two primary issues: 1) the low bitrate of YouTube videos, and 2) the bitrate-hungry nature of the source video. Vimeo’s x264 encoder is a little more efficient and should produce better results, but may not resolve the problem.

Low bitrate encoding produces the highest image quality when change is minimized; you want to construct shots so that pixels can be reused from frame-to-frame to the greatest degree possible. For example, a flat pan is better than a camera swivel because the image can just be repositioned in the following frames. Similarly, don’t move the camera when there is a lot of motion/change in the shot.

Here are some things to consider when trying to improve the quality of low-bitrate video:

– degree of change within the subject matter
– level of image detail
– camera movements and/or changes in perspective
– length of each shot (i.e. frequency of cuts)
– framerate and frame dimensions
– codec and encoder settings

On one extreme, HD movies with high motion, quick cuts, detailed images, and moving cameras will need to be encoded at high bitrates to look good. At low bitrates shots should be simplified if you want to produce good quality.

FYI: The file you submitted is 0.81 bits/pixel at 1080p. YouTube typically transcodes video to about 0.07 bpp. Apple uses around 0.12 bpp. I typically target 0.15-0.20 bpp at 480p for high quality streaming and provide a hi-def version for downloading.

[Ivan Myles]

These are work-arounds rather than solutions, but here are a couple ways to address the issue:

Edit clip on its own: Temporarily disable the upper tracks in the timeline, edit the target clip as desired, and re-enable the upper tracks.

Edit clip in context with other tracks: Temporarily move the target clip to the highest track and reduce its opacity. Edit as desired, move the clip back to its original track, and reset opacity.

[Ivan Myles]

Check that the keyframes in the Effect Controls panel are linear and not Bezier or Continuous Bezier.

Did you drag/reposition the video in the program window at any point?

It would be helpful if you posted a screen capture with the Effect Controls panel, timeline (with video tracks expanded), and Program Monitor.

[Ivan Myles]

As Ryan mentioned, it is probably the H.264 Level. Set this parameter first.

[Ivan Myles]

Yes, you will experience issues if the harddrive is nearly full.

There are several potential causes: encoding, hardware, software. Troubleshoot to determine whether the stuttering was encoded into the file or is a playback issue. View the file frame by frame in Premiere or QuickTime to ensure there is smooth motion in the encoded file. If the file looks good, are you reading from a platter disk or SSD? Are there any effects applied in Premiere? Are there other video tracks in the Premiere timeline?

[Ivan Myles]

[Abel Fernandez] “I have the same issue, but if I just unlink it and set the new size to 1280×720 the video gets distorted.”

Check the Aspect setting. Otherwise, please provide more information regarding the observed distortion. A screen capture would be helpful.

[Ivan Myles]

I have experienced issues when changing the frame rate of compressed source files. Here are two approaches:

1) Instead of using the 50fps footage directly in the 25fps timeline, create a 50fps sequence for the source file. Insert the 50fps sequence into the main 25fps timeline and adjust Speed/Duration of the inserted sequence accordingly. Or,

2) Transcode the source file into an all intra-frame intermediate format such as ProRes, DNxHD, AVC-I, DPX, or uncompressed YUV. Be sure to check/adjust the luminance and RGB levels before transcoding. If you don’t need the source footage at its native frame rate, transcoding at 25fps will save file space.