ffmpeg tips

ffmpeg.sh

# video to image by fps
ffmpeg -i in.mp4 -vf fps=1/5 pic%03d.png

# video to image by input seeking
ffmpeg -ss 5 -i in.mp4 -frames:v 1 pic.png

# https://trac.ffmpeg.org/wiki/Seeking
# cut from 00:05 to 00:10
ffmpeg -ss 00:05 -i in.mp4 -t 00:05 -c copy -copyts out.mp4

# segment video
ffmpeg -i in.mp4 -c copy -f segment -segment_time 10 out%03d.mp4
ffmpeg -i in.mp4 -c copy -f segment -segment_time 10 -reset_timestamps 1 out%03d.mp4
ffmpeg -i in.mp4 -c copy -map 0:0 -f segment -segment_time 5 -reset_timestamps 1 out-%03d.mp4

# segment video into small chunks(2s)
ffmpeg -i in.mp4 -segment_time 2 -g 60 -sc_threshold 0 -force_key_frames "expr:gte(t,n_forced*60)" -f segment -preset veryfast out-%03d.mp4

# show frames information
ffprobe -show_frames -pretty in.mp4

# get h264 rawvideo
ffmpeg -i out1-000.mp4 -c copy -f h264 out1-000.h264
ffmpeg -i out1-001.mp4 -c copy -f h264 out1-001.h264
...

# concat demuxer
# https://stackoverflow.com/questions/7333232/how-to-concatenate-two-mp4-files-using-ffmpeg
# >cat files
# file '/Users/XXX/demo/concat/./out1-006.h264'
# file '/Users/XXX/demo/concat/./out2-002.h264'
# file '/Users/XXX/demo/concat/./out1-002.h264'
ffmpeg -f concat -safe 0 -i files -c copy output1.mp4

# concat protocol
# convert to ts
# https://trac.ffmpeg.org/wiki/Concatenate
ffmpeg -i intro.mp4 -c copy -bsf:v h264_mp4toannexb -f mpegts intro.ts
ffmpeg -i text1.mp4 -c copy -bsf:v h264_mp4toannexb -f mpegts text1.ts
...
ffmpeg -i end.mp4 -c copy -bsf:v h264_mp4toannexb -f mpegts end.ts
ffmpeg -i "concat:intro.ts|text1.ts|text2.ts|text3.ts|end.ts" -c copy output.mp4

# merge audio
# https://superuser.com/questions/277642/how-to-merge-audio-and-video-file-in-ffmpeg
ffmpeg -i output1.mp4 -i audio.aac -c copy output2.mp4

# convert video for iOS
# https://trac.ffmpeg.org/wiki/Encode/H.264
ffmpeg -i output2.mp4 -preset veryfast output2-veryfast.m4v

# convert video for swf
ffmpeg -i output2.mp4 -preset veryfast output2-veryfast.swf