I am using ffmpeg & mp4box in my PHPmotion site to convert videos to mp4 format. When I convert a 50MB video to mp4, the file size remain same. So Its affecting the video streaming in my site. So I want to reduce the file size of the video in conversion. This is my code example, that I've used the site for converting m4v videos in PHPmotion.
$ffmpeg_cmd2_2 = "$config[path_to_ffmpeg] -i $raw_video_path -vcodec libx264 -vpre veryfast -crf 15 -b 5120000 -threads 0 -acodec libfaac -ac 2 -ab 128k -ar 44100 -f mp4 $new_flv_1";
$mp4box_cmd = "$mp4box_path -add $new_flv_1 $new_flv_2"
When I use this command,it converts the m4v file to mp4 format, but the filesize doesn't change. What command I should use in this to reduce the filesize during video conversion in PHPmotion? Can anyone write a ffmpeg command to reduce the filesize during conversion ?
There are two main factors involve in reducing the size of mp4 video
i: width and height of video, greater their widths, greater will be size and slower will be streaming e,g 360p, 480p, 720p, 1080p
ii: video bitrate, greater will be their bitrate, higher will be quality, size and slower will be their streaming.
For faster streaming i recommend using
i: 480x360 or lower width and height of video ii: -b value 360k or lower. iii: -ab value 64k (optional)
Hope this will help you.
Apart from using smaller video frame size, you need to use higher crf value to achieve bitrate reduction while maintaining good video quality.
Replace this
-crf 15 -b 5120000
with
-crf 22