[Ivan Myles]

[Keith Betts] “Although it doesn’t appear in raw footage or exported ProRes Master file but in my compressed file the lines fluctuate and wave and are a utter distraction to me. Tried different compression settings to but to no avail.”

Please provide more detailed information: codec, screen capture of best export settings, screen capture or clip of the issue, how the video is being viewed.

[Ivan Myles]

I wasn’t thinking of that specifically, but it is part of what I meant. Basically, you want to minimize the level of variation in each shot so the encoder can dedicate more bitrate to image quality. Every little bit [!] counts because online streaming tends to suffer from bitrate starving.

Regarding repositioning/resizing: with 4:2:0 source footage and 4:2:0 output, if the image is moved or resized the colors get remapped and subsequently blurred. Angelo Lorenzo posted recommendations regarding image sharpening that might be helpful.

[Ivan Myles]

Thank you for posting the images. Unfortunately, the results look normal/expected. The difference between the high bitrate H.264 video and the source file is probably attributed to 4:2:0 subsampling. (Was the video resized or re-positioned?) The degradation in the low bitrate file is likely due to high compression.

You could try applying the Warp Stabilizer effect to see if results improve. Also, consider re-editing some of the footage to minimize transitions between direct sunlight and shadows. Create a short test file rather than making changes to the entire video.

[Ivan Myles]

Yes, please post a short clip. It would also be helpful if you could post the same footage from the camera (or at least a screen capture showing the same frame from the source file and exported H.264).

Are you applying any effects to the clips?

Please also list or post a screen capture of the sequence settings.

At high enough export settings there should not be a significant difference between the source footage and exported H.264. Try boosting Target/Max bitrate to 40/62.5 to see if there is any difference.

[Ivan Myles]

To assure the best quality you could upload a ProRes or DNxHD file. It’s overkill, but low risk. Here are high quality H.264 settings:

– 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; 1920×1080; 30 fps (or 29.97, if appropriate); VBR, 2-Pass; 20-25 Mbps target bitrate; 40+ maximum bitrate; key frame distance 15 frames; enable Maximum Render Quality

YouTube recompresses videos at a very low bitrate, so ultimate quality also depends on the level of complexity and motion in the video.

[Ivan Myles]

Jordan, it looks like there are a few factors at play, and most are normal behavior. One is a bug, but it only relates to the case with the very low bitrate (737 kbps).

Unconstrained Maximum: Bitrate can only be so high based on the footage and encoder settings. The bitrate settings go up to 300,000 kbps using HiP@L5.1, but that doesn’t mean the encoder needs that much data.

For reference, take a look at the maximum allowed settings for each H.264 Level. HiP@L5.0 has a maximum allowed bitrate of 168,750 kbps, which correlates to 1920×1080 at 72.3fps. Doing the math, this is equivalent to 1.15 bits/pixel. Therefore at 24fps a 1.15 bpp video stream would be about 56 Mbps. Actual results will vary depending on encoder settings and the nature of the footage. The 21 Mbps rate in your example is equivalent to 0.45 bpp. This might seem low, but we need to consider other factors (see below).

GOP Length: If you want to force bitrate to be higher, set Key Frame Distance to a very low number. This will increase file size, but will not necessarily improve quality beyond a certain point. I typically set Key Frame Distance to 10-15 frames for high motion footage.

The chart shown below is from a characterization study. Unconstrained average bit rate is relatively high when Key Frame Distance is set to one frame. In the study average bitrate stabilized around 0.5 bpp as Key Frame Distance increased. Therefore the 0.45 bpp rate of your 21 Mbps sample file is within reason, especially if the video is relatively static.

Bitrate Tuning: Tweaking the maximum bitrate setting will sometimes produce incremental changes in the actual encoded average bitrate. This relates to the size of the data blocks the encoder uses when breaking down larger frames.

CBR vs VBR: At very high bitrate settings CBR will be relatively high while VBR does not exceed its “natural” maximum. Beyond a certain point the CBR encoding just becomes inefficient without noticeable improvements in image quality. (CBR offers other advantages especially for broadcast video.)

Multiplexer: Under the Multiplexer tab be sure Stream Compatibility is set to Standard. It defaults to iPad which forces the H.264 Profile to Baseline.

Encoding Bug: One of the Premiere Pro updates last year introduced a glitch when trying to encode high bitrate H.264 files. Specifically, if the Target Bitrate is set too high the encoder spaces out (technical term) and produces files at only a few hundred kbps. This behavior was observed with direct exports; sending jobs to the Media Encoder queue seems to be OK.

I submitted multiple bug reports to Adobe; feel free to submit another. Perhaps the company will be more responsive if more people raise the issue. Note that this only relates to your 737 kbps file.

Other:
– The data rate reported in Windows Properties is not always accurate. As Vince noted above QuickTime is more reliable. Also consider downloading the MediaInfo application.
– Please upload a screen capture or short video of the exported file. How does image quality compare between the source file and the encoded H.264 file?
– How will the video be used? There are not many reasons to encode 1920×1080-24p H.264 video at 88 Mbps.
– Compression is relatively complex. Be prepared to try different things and read reference material to become more familiar with the settings and practices.

[Ivan Myles]

I empathize with your situation, but there might be a simple solution to the error message. Check the text file on your harddrive listing Adobe-approved cards (do a file search for cuda_supported_cards.txt). Close all Adobe apps, open the file, and add the card to the list if it does not already appear.

[Ivan Myles]

Click on the time/frame number in bottom right corner of the Source Monitor and type + and the number of incremental time/frames to move the playhead to the desired out point (in this case +00:10:12).

[Ivan Myles]

I recommend setting Key Frame Distance to 12 frames instead of every frame.

[Ivan Myles]

Adobe Illustrator is probably the better tool for generating complex shapes. Good luck.