Converting High Quality ProRes 4444 to MP4 for web
Hello again folks!
Recently, our short film was mastered at Fotokem. In addition to getting a DCP, we also received a high-quality QuickTime, codec ProRes 4444.
Ideally, I want the highest Quality .mp4 file from this file so that we may send off to festivals, both for prepping a dvd and for ftp/cloud uploads to festival servers. I would also like a decent filesize.
I wanted to export as a high quality mp4, so i matched most settings except putting level at High 4.2. can anyone tell me if this is a good recipe and if not, please recommend ideal settings to get a high quality MP4, codec H264 from a Quicktime, codec ProRes 4444?
[Don Mick] "Ideally, I want the highest Quality .mp4 file from this file so that we may send off to festivals, both for prepping a dvd and for ftp/cloud uploads to festival servers. I would also like a decent filesize."
So these 2 things are in constant struggle. Quality vs. file size. They aren't necessarily mutually exclusive, but the bigger the file size generally the better quality your final product.
[Don Mick] "I wanted to export as a high quality mp4, so i matched most settings except putting level at High 4.2. can anyone tell me if this is a good recipe and if not, please recommend ideal settings to get a high quality MP4, codec H264 from a Quicktime, codec ProRes 4444?"
There's no magic bullet for this stuff. The presets in Media Encoder are a good place to start and you can tweak from there. Match settings is fine, but you'll want to focus on your data rate. The Mbps is telling the software how many bits to throw at an image. The more bits the better the image, but the larger the file size. The level is a specification dictating what the data rate range can be, and also what devices the file can play on (older devices can't play the newer, higher levels).
You'll also want to take a look at CBR vs. VBR - or Constant Bit Rate vs. Variable Bit Rate. In general a CBR will give you the best quality and the biggest file size. VBR typically will give you acceptable quality and a smaller file size. A CBR approach is going to take the data rate you've set and indiscriminately through it at the image. So if you specify 5Mbps, all 5Mb's will be used all the time. In a VBR setup, the software will attempt to use only what is necessary to define the image. So if it can use less, it'll use less. Tradeoffs for VBR - sometimes the quality isn't as good, and it takes longer since it's doing more estimation than a CBR).
These are all very general rules. There are caveats to all this, but hopefully that points you in a direction. Also take a look at YouTube and Vimeo's compression guides. Vimeo has tutorials on their site for all encoding software. This may give you some additional help:
Thanks again for your help.
Here is a summary of what happened:
our team found out that many festivals use either withoutabox, Film Freeway or both as an online submission for your film instead of a DVD (or prefer it to dvd). They both have a file size limit of 10gb for 1080p files. What we did was export another quicktime with h264 codec and a stereo mix instead of our surround sound mix. (AAC codec) The large file fotokem gaves us appears to be for theatrical playback.
in order to achieve the 10gb file limit, i set quality to 90 in Adobe media encoder's settings. i made sure to use max render and render at max depth settings. sound at 320kbps, 48hz.
for the mp4, i can't remember what bitrate was used, but i just kept going until i got close the 10gb limit. the result was still high quality and acceptable for screener quality.
oh lastly i forgot to mention that i put VBR two pass. it seemed like a better deal for quality and also for file size. my understanding of these two, VBR and CBR, seems like that VBR two pass can produce just as good of a quality in most cases than VBR, with less file size. however, a two pass VBR is cpu intensive and can easily triple your export times. (i7-4710hq) i set max bitrate to 300 so that the VBR will never hit a 'ceiling' ; the target is set for 25,50,70, etc but has a max allowable of 300.
i did not set "key frame every 'x' frames", i usually have that unselected, which i'm guessing is either off or automatic. either file, the quicktime or MP4, is high enough to show someone a quality, color corrected version of our film while also good enough to create DVD copies from.
off to the festivals we go!