Reduce file size of an .mp4

[Erin Pelkey]

I have a series of 5-7 minute training videos that I provide on YouTube and for download. The videos include live footage, imported audio, and image overlay. I haven't implemented any video effects or major transitions, other that 'Cross Dissolve.'

I export to mp4/H.264 codec, reducing bitrate and frame size (even though I understand this shouldn't matter as much), but am still ending up with 250-300MB files. While I am able to upload to YouTube, I'm not able to provide these files for download as they are considered too large.

My question is if there are additional actions I can take to provide a smaller file size. I can't find a consistent answer as to what my file size should be for these short videos.

I'm going back to school to learn more about video soon, but obviously that's not a sufficient answer to a customer.

Any guidance on this topic is greatly appreciated.

Thanks, in advance!

[cc_merchant]

File size = (number of frames) x (bitrate per frame).

To reduce size either lower the number of frames (shortening the time-line or FPS) or lower the bitrate per frame (reducing quality).

[Erin Pelkey]

Thanks so much! I will definitely keep this equation in mind from now on...

[Peter J Kovacs · Accepted solution]

Actually 250mb sounds very reasonable for 5-7 mins of full HD 1080p footage.

With variable bitrate H264, a major part of the filesize depends on the dynamics of the video. So if the video has lots of camera motion, moving background elements (ie. flapping leaves in a tree), scene changes, fast cuts, shaky camera, and grainy footage it will increase the filesize. For example, shooting a scene on a tripod vs. handheld could give you a much smaller file. This happens because H264 (like most mpeg encoders) uses information from neighboring frames/pixels during the encoding process... and the more the information changes, the more bits is needed.

Anyways, try a really low bitrate like 2 average 5 max for 720p and 5 average 8 max for 1080p. Then check to see if it still looks good visually (no obvious compression artifacts).

Personally, I use an x264 based H264 encoder like HandBrake (which is free) set to constant quality 23.

-Pete

[Erin Pelkey]

Ah, thanks so much! More than anything, I think I just needed to hear someone say that this file size was reasonable, but the bitrate info is incredibly helpful, as well. So, thanks!

[ArunGovam]

Handbrake is worked!!! Excellent!!!!