Advice on compressing to MP4

[Jesse Alk]

I'm submitting a feature documentary to a festival with very specific upload requirements and am having no luck getting a watchable copy at these specs. I'm a novice at compression techniques, and using Apple Compressor. Any advice on how to get this looking passable would be greatly appreciated. It's a 77 min 1080p feature, 23.976, stereo audio. When I try to encode at 1.5 Mbps (1500 kbps) I end up with a file a little over one GB, which looks unusable. I'm compressing from a 138.8 GB 422 Pro Res HQ master. Thanks.

Specs provided by festival:

Container: MP4 (H.264)
Max File Size: 2 GB
Max Bit Rate: 1.5 Mbps
Constant Frame Rate (CFR)
(Variable Frame Rate (VFR) is NOT acceptable.)

[Pete Cofrancesco]

You can give Handbrake a try. I use the Best Quality preset in Apple Compressor then re encode with Handbrake at around RF22. But honestly at that low of bit rate especially at constant it’s going to look bad no matter what you use.

[Gary Huff]

At that low of a bitrate, you need to be in SD. Just deliver your movie in that resolution.

[Pete Cofrancesco]

agreed or 720p as a compromise

[Seth Bloombaum]

Somewhat agreeing with the above posts!

Throw your ProRes HQ master into Handbrake.

Figure out the not-quite-intuitive settings to bring it down to 720p, and, use the Bitrate method at 1.5Mbps instead of the Constant Quality method (the RF numbers, which for your specs would involve some trial and error).

Unless there’s a lot of picture complexity (handheld shaky camera, moving water, leaves/grass blowing in wind, sports) you should get a good result - please post back as to how this works for you. If there is a lot of picture complexity, you’d next consider 854x480, which should be great at 1.5Mbps even if complex.

Note that Handbrake includes the best MP4 encoder (x264), the best scaler to get your resolution down (Lancsoz), and, incidentally, the best deinterlacing method (Yadif). It’s been quite some time since I used Apple Compressor; Handbrake is excellent.

[Roger Gunkel]

I don't disagree with what has been suggested, although my main work is weddings which I convert to mp4 at a variable BR of minimum 10mbs and max of 14mbs to maintain a decent image quality. That BR gives me a maximum file length of 55minutes which will allow for 4Gb limit on Fat 32 formatted sticks. I use Fat 32 as it is the most universally readable in my experience. I also use variable BR to allow for any sections that contain more movement.

Using those figures would mean reducing the Bitrate to about 7mbs min and 10mbs max to accomodate your 77 minutes in one file on a Fat 32 drive. I would suggest testing short clips of perhaps 30 secs each to see what is acceptable to you with different bitrates.

JUST EDITED TO SAY: Sorry, missed the spec submitted at the bottom of your post, so 3.5mbs would be about the best you could use for one file at 77mins. I think they are expecting too much if they want decent quality within the spec they have suggested and will look poor on any reasonable sized screen in my opinion if limited to 1.5mbs and 2 Gbs. Also just a thought, H265 would possibly give better results than H264

Roger

[Gary Huff]

I would not use H.265 unless that is absolutely in the spec. H.265 requires horsepower to decode, and it may not even be compatible with what they may be using on the backend, just stay away from that.

[Seth Bloombaum]

Originally Posted by Roger Gunkel

...Also just a thought, H265 would possibly give better results than H264

Originally Posted by Gary Huff

I would not use H.265 unless that is absolutely in the spec. H.265 requires horsepower to decode, and it may not even be compatible with what they may be using on the backend, just stay away from that.

I have to agree with Gary here. h.265 delivers great quality at bitrates of 1/3 to 1/2 that of h.264 in my testing. But, I’m frequently running into compatability issues on playback, even on devices that list compatibility. It’s gonna’ be great someday...