I\’m not an expert in Video Editing but what I want to understand the logic of Whatsapp video processing. First of all I have noticed that whatever the file is, Whatsapp sets the limit of Uploaded videos to 16MB, after which whatsapp crops the video to not exceed the limit. is this a convention or it\’s a personal choice ? Secondly, When a video is recorded using the Camera it\’s not compressed by default, so whatsapp gb compresses it using FFMPEG I guess, and it takes no time. (tried for a video of 1min 1920×1080 with 125MB of size, becomes 640×360 with 5MB of size in no time, and the upload starts automatically).. how may they do this ? and why the choice of 640×360, It seems to me very fast for 2 asynchronous tasks : Compression + Upload. When I run the compression command ffmpeg -y -i in.mp4 -codec:v libx264 -crf 23 -preset medium -codec:a libfdk_aac -vbr 4 -vf scale=-1:640,format=yuv420p out.mp4 it takes approximatively 1 min and the video is being rotated !! 😀 Finally, when we download a video from Youtube it\’s already compressed (I guess) and whatsapp doesn\’t even try to compress it. So I think that it automatically detects thats the video is compressed. How can we detect this ?
I have received a solution from my friend that When you record a video using the camera on your device, it’s typically stored in a high-quality and larger file size format. To optimize video transmission and reduce file sizes, GB WhatsApp employs compression techniques using tools like FFMPEG.
The choice of 640×360 resolution is likely a trade-off between video quality and file size reduction. By reducing the resolution, the file size decreases while still maintaining acceptable visual quality for viewing on mobile devices. This choice is influenced by factors such as limited screen sizes and data usage considerations.