Html5 Video: Ffmpeg-encoded Mp4 Not Playing In Any Browser (plays In Vlc Though)

I am trying to serve HTML5 video in MP4 and WEBM fomats. I cannot get all browsers to work though: Browsers which support WEBM (Chrome desktop, Firefox desktop) play the videos f

Solution 1:

No MP4-playing browsers actually seem to have full support for MP4 - especially problematic for MS and Apple's browsers which are trying to create a royalty-hell / monopoly around the format.

I got it to work by re-encoding with the following FFMPEG parameters:

-pix_fmt yuv420p-preset slow-profile:v baseline

Giving a full command line of:

ffmpeg
  <INPUT DEFINITION>    # e.g. -i <FILE>
  -an    # if you won't want audio, otherwise -acodec libaac -b:a 128k
  -s hd720
  -vcodec libx264
  -b:v BITRATE    # e.g. 4M
  -vcodec libx264
  -pix_fmt yuv420p
  -preset slow
  -profile:v baseline
  -movflags faststart
  -y <OUTPUT PATH>

The problem was ultimately yet another example of proprietary software vendors not properly supporting their own standards.