[FFmpeg-user] format for internet explorer post 8

Tim Hiles thiles at confex.com
Sat Mar 28 23:57:12 CET 2015

> The input has no audio, and why suggest '-async 1'? Also, libx264
> ignores '-qscale', so the default of '-crf 23' will be used instead.
Thank you Lou.  That helps me with a few things that I was unaware of.
That command is what I've typically used and have had good results with
playing mp4's in various browser players and hence why I suggested the user
try it.  I know I'm not the end all be all of ffmpeg so I assumed others
would have other suggestions.   I'll update it and compare and see if I see
different results.  In regards to no audio present in the users question I
confess I didn't think to look.

A question then is raised for:

The actual solution is shown in the console output:

"No pixel format specified, yuv444p for H.264 encoding chosen.
>  Use -pix_fmt yuv420p for compatibility with outdated media players."
> Of course, another solution is to use a more capable player.

Are you and ffmpeg suggesting that movflags faststart not be included in
the command, and that simply changing to -px_fmt yuv420p will play mp4
files better?  Without the movflags faststart present I've seen certain
browsers balk at playing mp4s without it.

More information about the ffmpeg-user mailing list