@ Cormac

Have you considered or tried converting your avi files to Image sequences for that functionality?
(use the "vMix Video Tools" in the Windows Start Menu vMix folder)
I find avi files are hard drive intensive and can often be choppy depending on what else you have going on.


Ice

Some will disagree- Tom at ESB should chime in here -

But i get lower render times (which is the key) when recording in Mpeg-2 vs Mpeg 4.

This is on an i7 with a 1GB Nvidia.

Youtube seems to accept MPEG2, but no it's not ideal for direct upload to the web. The main reason is it's not as highly compressed. Which is why it is fast in editing and recording. It's an older format, but a quite a reliable format. For me the best feature is it seems to be good at file splitting, so you have have a new file every 30 minutes without upsetting anything. The joins are seamless between files. Often on MP4 if a few bytes get corrupted you can lose a substantial part of the video or in some cases all of the video. MPEG-2 .ts you generally just lose just the area of the corruption.

For the web your goal is the max compression with best visual quality. The best protocol for the web might be H.265 also called HEVC, except it's quite intensive to encode and decode. So your user has to have a fast computer and with so much Mobile everything, you can't assume every viewer is going to have a Core i3 or equivalent decoding capability or a video chip dedicated to decoding the video. (it will happen soon).

So H.264 is really the most popular choice, because most smartphones/tablets play it just fine (not just the new ones).

I've concluded in my workflow MPEG2 .ts is great for recording.

H.265 (HEVC) is great for Archiving footage where disk space is at a premium.

H.264 is the best choice right now for streaming due to wide compatibility.

.AVI or .MP4 or .TS are really containers and have their own pros/cons and subsets of features. You can even change the "container" without re-encoding the video if the codec is the same. Personally I don't care too much about the container except that my video editor plays nice with it.

That's my $0.02, you might have different requirements and a different workflow. If you can't accept any quality loss archiving, you may not want to re-encode at H.265 lower bitrates as I do all footage more than a year old. You might just want to use H.264 all the way. I used to, but found it wasn't for me and rather do the work to use all 3 of the above codecs for their specific roles in my workflow. It was better, even though a little more time consuming. (I let those big encoding jobs run when I sleep).