Standard Compression
Adobe Media Encoder preset – ‘Vimeo 1080p Full HD’ (larger file size, better image quality)
- It has a target bitrate of 16Mbps and creates a file that is about 120 Mb/minute. But it is perfectly fine to select the Vimeo preset and then lower the bit rate to around 12.
- This works well for online submissions, crit sessions and the like. As long as the original image quality is reasonably good in terms of light and contrast, compression can hardly be noticed.
- One important thing with this preset is to make sure that it is set to 25fps and not 50fps, since it will either take twice the file space or lower the quality significantly.
- In general, there is no reason to shoot in 50p unless you are planning to use slow-motion in the final edit. There used to be a setting for 50i, which is a frame rate not used anymore and has been replaced by 25p.
- Note about terminology: while 25fps means that there are 25 frames per second, 25p means that there are 25 frames per second and that they are recorded progressively. 50i means that there are 25 frames per second and that they are recorded interlaced.
Smaller Compression
Adobe Media Encoder preset – ‘Match Source – Adaptive Low Bitrate’ (smaller file size, good (enough) image quality)
- With this preset, the image quality should be acceptable and the file size will be brought down to around 30-40 Mb/minute.
- This preset will work better in remote areas with poor internet. For smaller clips, one could even send these files through a mobile phone connection. The difference in quality with the above is hardly noticeable in normal lighting conditions.
- In theory, though not recommended, the target bitrate could be lowered if circumstances require it. It is not advisable to go lower than 4 Mbps.
Optimizing long cuts for slower internet: When uploading your Rough cut or Fine cut to Kaltura Media Gallery: Set bitrate to 6 Mbps. Chose VBR, 2 pass for best quality without increasing the size. A 30-minute sequence will result in about 1.5GB.
Step-by-step:
- File -> Export -> Media
- A pop-up export window opens
- Select under format: H.264
- Select under preset: Vimeo 1080p Full HD
- Click the file name in blue to select the output location (and new name)
- Halfway down the settings page, select the tab called ‘Video’.
- Scroll down to ‘Bitrate Settings’
- Change the Target Bitrate (the blue number) to 6
- Change the Bitrate Encoding in the dropdown menu to VBR, 2 pass
Finding the Optimal Compression
Before going ahead though, we suggest you do some testing to find the optimal compression. By setting in and out-points on your timeline, simply select one minute of your video and export the file using the suggested preset. Save it to your desktop. Once done, open it and review the quality. In case the quality looks good enough but you still want to create a smaller file, you can try lowering the bitrate target settings. If, on the contrary, you want to improve the quality by creating a larger file, you can increase the bitrate settings. To do that, follow these instructions:
- Select in and out-points of a minute piece of your video in order to test the new settings. Select ‘Export Media’.
- Media Encoder opens. Select ‘H.264’ under ‘Format’ and ‘Match Source – Adaptive Low Bitrate’ under ‘Preset’.
- In the central part of the column there is a section that can scroll. Make sure the video tab is selected and scroll down to nearly the end.
- The top image shows the ‘preset’ settings. The lower shows the settings you could try in order to increase quality. If you want to decrease file size, these numbers have to go down. Selecting ‘VBR, 2 pass’ will also increase quality but not increase file size. However, it takes your computer longer to execute the compression.
- Once encoded, open the resulting file and check for quality. Repeat if required.
- Once you have reached the compression that looks reasonable for you, select in and out-points for the entire video (or smaller parts, if required) and execute the encoding process.
