[Ivan Myles]

Try MediaInfo to determine the file attributes.

[Ivan Myles]

• You might need to use several tracking points in series to get through the clip.
• If individual points don’t work, try tracking the entire candle.
• If the image is low contrast, make another composition with the clip and blow out the levels to create high contrast between the candle and the surrounding area. Insert the comp with the modified levels into the main comp, track the high contrast candle, apply the motion data to the original clip, and hide the high contrast comp.

[Ivan Myles]

The higher the bitrate the better the picture quality. As bitrate decreases the pixels get grouped into larger blocks and the encoding gets more approximate / less accurate. This becomes especially problematic with frequent cuts and high motion footage.

For reference, YouTube videos come out to about 0.07 bits/pixel. Vimeo is a little higher, and Apple uses 0.12 bits/pixel. I consider 0.20-0.40 bits/pixel to yield good to very good quality in H.264. Blu-rays are encoded around 0.60-0.70 bits/pixel.

[Ivan Myles]

[Leo Kann] “I am starting with a 7,8 GB prores422/mov file, exported from FCP. I need to compress it to a mp4 150-200 MB .

Now I am using MPEG Streamclip and there are the well known options:

1. Reduce the “Quality” (whatever that means) and try to hit the desired size
2. Set the MBPS to match the desired size (for me it would be very low, 3,7 MBPS)
3. Downscale the Material (its Full HD)

Whats bringing the best results here? One of them? A mix?”

A mix of tactics will be required most likely. In addition to Craig’s recommendations, consider downscaling the frame dimensions so that the resulting file size and bitrate correlate to at least 0.10 bits/pixel (preferably higher). The calculation is as follows:

bitrate(Mbps) * 1024 * 1024 / width / height / frame rate > 0.10

Therefore, for frame rates of 24-30fps and a bit rate of 3,7 Mbps you would want to reduce your full HD file to 1280×720. If you keep it at 1920×1080 the data rate per pixel would be equivalent to a YouTube video.

[Ivan Myles]

YouTube allows high bitrate uploads. Is the 300MB file size arbitrary or is there a constraint behind it (like upload bandwidth, for example)?

The equivalent bitrate to meet your file size requirement for a 7 minute duration is 5.7 Mb/s. This is OK (though not maximum quality) for 1280×720 at 24-30fps, but a little low for 50-60fps.

In general, when encoding set maximum bitrate to 1.5-2X average bitrate, use a key frame distance of 1/2 frame rate, and enable 2-pass VBR encoding.

[Ivan Myles]

Hardware constraints will vary at different stages of the process. Have you tried using any system tools to monitor performance during the render/encode process? In general, SSD(s) would be a high priority. RAID with high speed I/O might be required depending on your usage scenario. Additional RAM is a low cost upgrade. Also consider things like a UPS and disk backup system which won’t necessarily boost performance, but might save time if something goes wrong.

[Ivan Myles]

Consider speaking with an attorney to discuss your options.

[Ivan Myles]

Looks fine on my phone. Where are you seeing the issues? First, download the Vimeo transcoded file and view frame by frame through the problem areas to be sure there is an encoding issue and not just a streaming bandwidth issue when viewing online. Second, if there is an encoding issue, consider increasing the number of frames between quick cuts, and reducing/slowing some of the motion. High compression encoding works by reusing pixel blocks from frame to frame. That can produce poor results when there is too much motion and too many quick cuts.

[Ivan Myles]

You seem to have everything set properly; perhaps someone with more intimate knowledge can comment. From a troubleshooting perspective I would try transcoding the ProRes file to H.264 with Premiere Pro and QuickTime Pro or Compressor, if available.

[Ivan Myles]

What are your delivery specs (codecs and media)? Do you plan to create discs (DVD/Blu-ray)?

Alternative audio tracks are saved as separate files and selected using the disc’s menu system. If you are trying to create a multiplexed standalone file–for example, H.264 for web distribution–you will need to create separate files for each language.

BTW, use short clips as test files instead of rendering the entire project.