a question about MP4s and the H.264 codec

[Dragonrider1227]

This will probably sound silly but are all MP4 videos automatically encoded with the H.264 codec? Or should I run all my videos through Zarx just to be sure?

[Qyot27]

No, MP4 is just a container, and can store MPEG-4 Part 2 ASP (aka Xvid), H.264, HEVC, and even MPEG-2 (although I'm sure that's extraordinarily rare; it's been a while since I checked, but it can probably even do MPEG-1, which would be even rarer than the MPEG-2 case).

[Dragonrider1227]

So I guess then I should always run my videos through something like Zarx if I want to make sure it has the H.264 codec?

[Dragonrider1227]

oh, and thank you

[Qyot27]

Use MediaInfo to check the files - it will tell you what format the video stream is and you can make the decision of whether to do anything to it. It's generally safe to assume it'll be H.264, but it's simply not a guarantee (not that you should be editing with H.264, but that's a separate topic). HEVC will probably be getting more common in the next few years.

[Dragonrider1227]

Okay, thanks. I'll take a look at that. I'm not editing with H.264, I'm saving my final product as one and wanted to know if when saving it as an MP4, it automatically has that codec. Since so many contests prefer videos with it.
What's HEVC?

[Dragonrider1227]

That program helpe me out. Thanks. And I figured out what HEVC is. Sounds like a good successor but it is getting hard to keep up XD

[Qyot27]

Well if it's saving on output, then yes, I would say that the odds are extremely high that they mean H.264 when the option is for 'MP4'.

I would recommend exporting from the editing program as lossless, preferably the same format you were editing with, and then encode for distribution after the fact (so yes, give the lossless output to Zarx). The H.264 encoders shipped with editing programs are probably not as good as x264 is.