Losslessly compressing screenrecording of video chat

Question

I have a screenrecording of a video chat I had and the filesize is massive because the screen recording itself was done at 59.93 fps. However, I think the video chat was something like 15-30 fps. Plus it was a video chat, so the individual frames were obviously compressed as well.

I don't want to lose the quality of the video (it's already somewhat poor considering it was a vid chat). However, I'd like to reduce the filesize. I don't quite know how to best go about this though... I suppose my question boils down to:

Is there a way to somehow lower the framerate of the video in a way such that it is in sync with the framerate of the vid chat?
Are there any other compression options I have that I'm unaware of?

Here's the ffmpeg -i output if that helps:

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '.\Untitled1.mov':
  Metadata:
    major_brand     : qt
    minor_version   : 0
    compatible_brands: qt
    creation_time   : 2015-08-02T20:32:54.000000Z
    com.apple.quicktime.make: Apple
    com.apple.quicktime.model: MacBookAir4,2
    com.apple.quicktime.software: Mac OS X 10.10.4 (14E46)
    com.apple.quicktime.creationdate: 2015-08-02T12:46:10-0700
  Duration: 00:45:19.57, start: 0.000000, bitrate: 12981 kb/s
  Stream #0:0[0x1](und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, bt709, progressive), 1438x874, 12974 kb/s, SAR 1:1 DAR 719:437, 59.93 fps, 60 tbr, 6k tbn (default)
    Metadata:
      creation_time   : 2015-08-02T20:32:54.000000Z
      handler_name    : Core Media Video
      vendor_id       : [0][0][0][0]
      encoder         : H.264

mashuptwice · Accepted Answer · 2022-02-18T09:00:10.663

FFMPEG simply drops "unnecessary" frames of the video when using -filter:v fps=n

A detailed explanation can be found here

By additionaly converting the video from h264 to h265 you can compress the video by approximately a factor of up to 10, without a noticeably quality loss. That means a 100MB file would only take up 10MB of space afterwards, without taking the reduced framerate into consideration.

Example:

ffmpeg -i <input> -filter:v fps=30 -c:v libx265 -vtag hvc1 -c:a copy <output>

Losslessly compressing screenrecording of video chat

1 Answers1