two different file sizes when airdropping from icloud photos...

kofman13

macrumors 6502
Original poster
May 6, 2009
255
75
When i drag a video out of the Photos app on my macbook to desktop (it pulls it from icloud first), the file is around 410MB. but when i airdrop the same video from my iphone to my macbook (it "prepares" from icloud first as well), it is a larger 589MB. why is the same video coming out to two different sizes? the lower size one worries me that it might be a degraded/compressed/lower quality version. i just want to make sure i am exporting the full quality
 

cynics

macrumors G4
Jan 8, 2012
11,303
1,695
What are the models/year of the devices being used?

You are experiencing a conversion for file compatible. The smaller file is HEVC/h265 (newer encoding) the larger is h264 (older encoding). HEVC is more efficient encoder so it can compress higher quality into the same file size or the same quality into a smaller file (or a combination of bit more quality into a bit smaller file). Apple is using a smaller file with the same quality.

HEVC requires a lot more computational power (or dedicated HEVC decoder) play/edit the file smoothly. One of your devices isn't capable of this so iOS/MacOS is transcoding to a compatible version as it being sent.
 
  • Like
Reactions: nicho

kofman13

macrumors 6502
Original poster
May 6, 2009
255
75
What are the models/year of the devices being used?

You are experiencing a conversion for file compatible. The smaller file is HEVC/h265 (newer encoding) the larger is h264 (older encoding). HEVC is more efficient encoder so it can compress higher quality into the same file size or the same quality into a smaller file (or a combination of bit more quality into a bit smaller file). Apple is using a smaller file with the same quality.

HEVC requires a lot more computational power (or dedicated HEVC decoder) play/edit the file smoothly. One of your devices isn't capable of this so iOS/MacOS is transcoding to a compatible version as it being sent.
macbook pro 2015, iphone XS. i have my iphone set to record in 265, so why is my phone sending a bigger file if my phone is set to 265 which is smaller
 

cynics

macrumors G4
Jan 8, 2012
11,303
1,695
macbook pro 2015, iphone XS. i have my iphone set to record in 265, so why is my phone sending a bigger file if my phone is set to 265 which is smaller
Your Macbook Pro (Haswell CPU) does not natively support HEVC. So if you record in HEVC on an iPhone and send it to the Macbook Pro the iPhone will convert it from HVEC (smaller file) to h264 (larger file) for compatibility. It wasn't until 2017 MacBook Pro (Skylake CPU) that HEVC decoding started to becoming a thing. Even then 2018 using Kaby Lake that hardware decoding AND encoding was a thing.

MacOS does well with HEVC though through software decoding. My 2013 iMac (Haswell) does good with basic video with 4k 30fps 8bit being about the limit before performance issues are easily seen.

I only have an iPhone 6S so I can't verify this but if you goto Settings > Photos > Transfer to Mac and PC > Keep originals you'll probably be able to play with the original HEVC. If not you can try recording a video, share to files, and then open the file on your Mac (iCloud). Right click "get info" on the video and you can see its codec.

HEVC
Screen Shot 2019-07-10 at 7.40.05 PM.png


h264
Screen Shot 2019-07-10 at 7.40.27 PM.png


Things to keep in mind. Your Macbook is using software to decode and encode HEVC which CPU intensive (more power/battery). Decoding might not seem like a problem but encoding using HEVC via software can be quite a long process. While its impossible to be perfect quality is very close with the sacrifice being file size (both are lossy). The majority of time this compatibility conversion is happening because the majority of computer can't play it which is why Apple made the transcoding process so transparent (and thus difficult to circumvent). iCloud Photo Library saves the original codec and devices supporting the codec won't get a converted version.

Hope this helps some. Personally I wouldn't worry about it.