How to decrypt video using FFmpeg?

I've managed to encrypt my video files using the ffmpeg command below; however, I can't find a way to save the decrypted output.

ffmpeg -i {file} -encryption_scheme cenc-aes-ctr -encryption_key {key} -encryption_kid {checksum} e.mp4

This post has an example for playing the video back using ffplay, which works, but I want to save the output to a file and want it done faster than normal playback speed.

I also tried using -decryption_key, but I get

Error while decoding stream #0:0: Invalid data found

when processing input with this command

ffmpeg -i {file} -max_muxing_queue_size 9999 -decryption_key {key} d.mp4

2 Answers

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You should use -decryption_key as input option.

ffmpeg -decryption_key {key} -i {file} -max_muxing_queue_size 9999 d.mp4

I am using the below ffmpeg command for file decryption.

ffmpeg -decryption_key {key} -i {file} -vcodec libx264 {output_file}