Blackmagic Forum

Hello all , I want to know how to reduce video file size for 1080 p quality .
I took a video footage for aroung 22 minutes in iphone in 1080p at 30fps and its size is 1.7 gb , now i just replaced audio file in davinci resolve 14 which is 49 mb only , Now i render in in quik time and h.264 1980p * 1080p quality , frame rate was 20000kb/s and finally clip is 3.7 gb , So please tell me the solution how i reduce the size in 1980 * 1080p olny.

I know my another clip is also going to be 20 minutes and around 1.5 gb in 1080p quality, so what should be the right setting in davinci resolve for rendering in 1980 * 1080p quality?

Gaurang patel wrote:
I know my another clip is also going to be 20 minutes and around 1.5 gb in 1080p quality, so what should be the right setting in davinci resolve for rendering in 1980 * 1080p quality?

Hi Gaurang

Without going to deep into what is quality and transcoding.

Think of it as a factor of 2 parameters BitRate and Duration - the higher the Bitrate the larger the file and (potentially) better the quality.. per second so if you have 22 minutes you have 1320 seconds - if you transcode at 20000 Kbs = 20 Mbs = 2.5 MBs x 1320 = 3.3Gb. Lower the bitrate and file size goes down as well as (potentially) quality on a given duration.

Then ther's where you started...

Your iPhone compresses video extremely (for it to be 1.7 GB on 22 minutes it had to shoot at about 10 Mbs)
As soon as you try to recompress its output you'll suffer from apparent generation loss if you try matching the original bitrate.

In your case I think you can try to compress to anywhere between 4500 to 12000 Kbs from Resolve for about 800 to 2 GB 22 min file, not sure how much it will preserve original quality...

If you have to use a smartphone for shooting, and want better end results, I'd warmly recommend using an app like Filmic Pro or Mavis where you have control over bitrate and can shoot up to 100 Mbs

hope this helps

Thank you very much for nice explanation Sir