Blackmagic Forum

For the last couple of betas I’ve noticed that videos rendered under h.264 (default settings, MP4) doesn’t playback properly on iOS.

On iPhone (iOS 14.3 both beta and release) audio plays back fine but video stutters badly. I’ve seen others complain about this in Facebook groups as well. It only seems to be an issue when it’s saved to the iOS device. If I save the video to the cloud and stream it from the cloud, it plays back ok. Only when played from the device does the problem appear.

MacOS 11.1 doesn’t have an issue playing it back. YouTube also doesn’t have an issue ingesting it. I’ve only noticed the issue on iOS.

UPDATE:

Did a whole bunch of testing. Videos encoded with HARDWARE ENCODING h.264 on the 2020 iMac i9 with AMD 5700XT (whether in Quicktime or MP4 wrapper) will not play without major stuttering on the following apple devices:

2020 13" MacBook Pro M1(MacOS 11.1)
iPhone 12 (iOS 14.3)
iPhone 12 Pro (iOS 14.3)
iPad (iOS 14.3)

it DOES play on ALL these devices if you DO NOT use hardware encoding on h264.

H265 Hardware encoding is just fine.

If I take the same thing and encode it on the MACBOOK M1 with HARDWARE ENCODING,

It plays back just fine.

So, maybe something with instructions to Intel processors with hardware encoding?

UPDATED again 12/16

Did a whole bunch more testing with iOS devices, Intel Macs, M1 Macs and Windows.

It looks like the bug is when you use h.264 hardware encoding on an Intel Mac (mine is a 2020 iMac 10th gen i9) and you play back that encoded file on a device with an APPLE-MADE chip like Axx or M1. Either of those do not playback right and have major stuttering. If you encode with SOFTWARE encoding it's not an issue.

Also... if you hardware encode ON THE M1 Mac, it plays back on Apple Axx and M1 AND intel just fine.

Hopefully this is something that can be fixed in DR17.