ffmpeg-cheatsheet

Cheat sheet for ffmpeg.

ffmpeg

understanding & examples

ffmpeg -i input_file […parameter list…] output_file
ffmpeg <global-options> <input-options> -i <input> <output-options> <output>

{Input_file,output_file} <=> {file, http, pipe, rtp/rtsp, raw udp, rtmp for all REGEX}

Supply '-f' in case your input file type is different from a normal file/rtsp stream. ex- grabbing screen, "images" as input regex.

ffmpeg -f image2 -i image%d.jpg –r 25 video.flv

ffmpeg calls the FFmpeg application in the command line window, could also be the full path to the FFmpeg binary or .exe file
-i is follwed by the path to the input video
-c:v sets the video codec you want to use
Options include libx264 for H.264, libx265 for H.265/HEVC, libvpx-vp9 for VP9, and copy if you want to preserve the video codec of the input video
-b:v sets the video bitrate, use a number followed by M to set value in Mbit/s, or K to set value in Kbit/s
-c:a sets the audio codec you want to use Options include aac for use in combination with H.264 and H.265/HEVC, libvorbis for VP9, and copy if you want to preserve the audio codec of the input video
-b:a sets the audio bitrate of the output video
-vf sets so called video filters, which allow you to apply transformations on a video like scale for changing the resolution and setdar for setting an aspect ratio
-r sets the frame rate of the output video
-pix_fmt sets the pixel format of the output video, required for some input files and so recommended to always use and set to yuv420p for playback
-map allows you to specify streams inside a file
-ss seeks to the given timestamp in the format HH:MM:SS
-t sets the time or duration of the output

SPEED vs. QUALITY vs. FILE SIZE (Lossy) encoding is always a trade-off between:

You can have fast, high-quality encoding, but the file will be large
You can have high-quality, smaller file size, but the encoding will take longer
You can have small files with fast encoding, but the quality will be bad.

ffmpeg -i <input> -c:v libx264 -crf 23 -preset ultrafast -an output.mkv
ffmpeg -i <input> -c:v libx264 -crf 23 -preset medium -an output.mkv
ffmpeg -i <input> -c:v libx264 -crf 23 -preset veryslow -an output.mkv

Transcoding: Conversion from one encoder to another. Ex- H264 to H265 Transmuxing: Conversion from one format/Container to another. Ex- mp4 to mkv

# Transcoding from one codec to another (e.g. H.264 using libx264):
ffmpeg -i <input> -c:v libx264 output.mp4
# Transmuxing from one container/format to another – without re-encoding:
ffmpeg -i input.mp4 -c copy output.mkv

Record Screen

# just video
ffmpeg -video_size 1024x768 -framerate 25 -f x11grab -i :0 output.mp4
# for audio too, co-ordinates are passed along with screen number, i.e. 100,200.
ffmpeg -video_size 1024x768 -framerate 25 -f x11grab -i :0.0+100,200 -f alsa -ac 2 -i hw:0 output.mkv

Remove audio/video

# disable audio
ffmpeg -i ibiza.mp4 -an ibiza_muted.mp4 # transcoding will be done if codecs differ.
ffmpeg -stats -i ibiza.mp4 -vn -c:a copy ibiza_novid.<container>
# disable video
ffmpeg -i ibiza.mp4 -vn ibiza_novid.mp3

Mux audio + video

ffmpeg -i audio.mp4 -i video.mp4 output.mp4

Grab webcam & dump

ffmpeg -f v4l2 -i /dev/video0 out.mp4

You can use the -ss option to specify a start timestamp, and the -t option to specify the encoding duration. The timestamps need to be in HH:MM:SS.xxx format or in seconds (s.msec).

The following would clip the first 30 seconds, and then clip everything that is 10 seconds after that:

ffmpeg -ss 00:00:30.0 -i input.wmv -c copy -t 00:00:10.0 output.wmv
ffmpeg -ss 30 -i input.wmv -c copy -t 10 output.wmv

Generate random noise

ffmpeg -ar 48000 -t 60 -f s16le -acodec pcm_s16le -i /dev/urandom -ab 64K -f mp2 -acodec mp2 -y noise.mp2

Add album cover

ffmpeg -i input.mp3 -i cover.png -c copy -metadata:s:v title="Album cover" -metadata:s:v comment="Cover (Front)" out.mp3

converting file to formats

ffmpeg -i MyMovie.mkv -vf scale=-1:720 -c:v libx264 -crf 0 -preset veryslow -c:a copy MyMovie_720p.mkv
ffmpeg -i MyMovie.mkv -vf scale=-1:720 -c:v libx264 -crf 18 -preset veryslow -c:a copy MyMovie_720p.mkv

The scale video filter is for resizing the video. You just set one size – which is the height in this example – and use -1 for the other dimension. ffmpeg will recalculate the correct value automatically while preserving the aspect ratio.

Srcs:

beyondszine / ffmpeg-cheatsheet