Comments on: Encode h.264 and WebM videos for MediaElement.js using FFmpeg

By: Aslam Doctor

Aslam Doctor — Sat, 20 Sep 2014 16:17:02 +0000

This is just perfect. Thank You for all the efforts in sharing. I had the MP4 files but they were not working on chrome. Now after using Your conversion method, its working perfectly.

By: Faron Coder

Faron Coder — Wed, 03 Sep 2014 22:52:18 +0000

Hello —

For those who use unix based ffmpeg – here’s the corresponding to author’s codes (above) in name of unix.

ffmpeg -y -i $fileid -vcodec libx264 -pix_fmt yuv420p -vprofile high -preset fast -b:v 500k -maxrate 500k -bufsize 1000k -vf “scale=trunc(oh*a/2)*2:480” -threads 0 -acodec libvo_aacenc -b:a 128k “$file.mp4” < /dev/null

ffmpeg -y -i $fileid -vcodec libvpx -quality good -cpu-used 5 -b:v 500k -maxrate 500k -bufsize 1000k -vf "scale=trunc(oh*a/2)*2:480" -threads 0 -acodec libvorbis -f webm "$file.webm" < /dev/null

ffmpeg -y -i $fileid -ss 1 -vframes 1 -r 1 -vf "scale=trunc(oh*a/2)*2:480" -f image2 "$file.jpg" < /dev/null
ffmpeg -y -i $fileid -ss 2 -vframes 1 -r 1 -vf "scale=trunc(oh*a/2)*2:480" -f image2 "$file.jpg" < /dev/null
ffmpeg -y -i $fileid -ss 3 -vframes 1 -r 1 -vf "scale=trunc(oh*a/2)*2:480" -f image2 "$file.jpg" < /dev/null
ffmpeg -y -i $fileid -ss 5 -vframes 1 -r 1 -vf "scale=trunc(oh*a/2)*2:480" -f image2 "$file.jpg" < /dev/null
ffmpeg -y -i $fileid -ss 10 -vframes 1 -r 1 -vf "scale=trunc(oh*a/2)*2:480" -f image2 "$file.jpg" < /dev/null

By: Peter

Peter — Thu, 20 Feb 2014 15:47:02 +0000

For backup, example (from that web site):

This will create one thumbnail image every minute, named img001.jpg, img002.jpg, img003.jpg, … (%03d means that ordinal number of each thumbnail image should be formatted using 3 digits)

ffmpeg -i myvideo.avi -f image2 -vf fps=fps=1/60 img%03d.jpg

By: Peter

Peter — Thu, 20 Feb 2014 15:45:40 +0000

For image thumbnails. Your sample means that ffmpeg must load video file each time it will generate image thumbnail from it. This can be expensive on memory consumption. There is another way to extract multiple image thumbnails from video at once. Sample: https://trac.ffmpeg.org/wiki/Create%20a%20thumbnail%20image%20every%20X%20seconds%20of%20the%20video

By: Dan

Dan — Wed, 14 Aug 2013 21:32:05 +0000

Hi Chris, great article! It helped me to get started with webm encoding.

I couldn’t figure out why my webm videos would play on Firefox and Chrome, but not Android, so I did some testing and analysis and discovered that the formula for resizing would only work for my Android S3 if the formula was: scale=trunc(oh*a/16)*16:x where x is a multiple of 16.

I may be incorrect, but it seems to be consistent in my results.

I hope this helps some peeps out!

By: Chris Coulson

Chris Coulson — Wed, 13 Feb 2013 22:38:46 +0000

In reply to Mike. Thanks for pointing that out. It's actually supposed to be AAC (for the audio codec used). I've updated the post.

By: Mike

Mike — Wed, 13 Feb 2013 22:29:18 +0000

It’s probably just a typo in your batch file, but I think you mean (H.264 / AVC) rather than ACC. If this is the biggest problem either of us run into, we’re in good shape. Thanks for this!