My Frequently Used FFmpeg Commands

Compress Video with Given Encoding Parameters

ffmpeg -i input.mp4 -c:v libx264 -b:v 6000k -b:a 192k -vf scale=1920:1080 output.mp4

• -i: Input file
• -c:v: Video codec
• -b:v: Video bitrate, 50m for 4K and 6000k for 1080P are advised.
• -b:a: Audio bitrate
• -vf scale=1920:1080: Filter, scale video resolution
• output.mp4: Output file

Hardware Acceleration

FFmpeg has a lot of hardware acceleration supports for each platform, for example, videotoolbox is the hardware acceleration codec for macOS:

ffmpeg -i input.mp4 -c:v hevc_videotoolbox -tag:v hvc1 output.mp4
ffmpeg -i input.mp4 -c:v h264_videotoolbox output.mp4

• -c:v hevc_videotoolbox: Use hevc_videotoolbox as the video codec
• -tag:v hvc1: Set the video tag to hvc1 for Final Cut Pro HEVC support.

Filters

ffmpeg -i input.webm -c:v libx264 -vf scale=1920:1080,zscale=t=linear:npl=100,format=gbrpf32le,zscale=p=bt709,tonemap=tonemap=hable:desat=0,zscale=t=bt709:m=bt709:r=tv,format=yuv420p output.mp4

• -vf: Filters
• scale=1920:1080: Scale video resolution
• zscale=t=linear:npl=100,format=gbrpf32le,zscale=p=bt709,tonemap=tonemap=hable:desat=0,zscale=t=bt709:m=bt709:r=tv,format=yuv420p: SDR Color grading

Copy Audio or Video Streams

ffmpeg -i input.mp4 -c:v copy -c:a copy output.mkv

• -c:v copy: Copy video codec
• -c:a copy: Copy audio codec

Copy Audio out of a Video File

ffmpeg -i input.mp4 -vn -acodec copy output.aac

• -vn: Disable video
• -acodec copy: Copy audio codec

Convert Video with Similar Bitrate

Tips: Convert video with similar or higher bitrate preserves the quality of the original video well.

Firstly, we need to get the video and audio bit_rate of the input file:

ffprobe -v quiet -print_format json -show_entries stream=index,codec_name,codec_type,bit_rate input.mp4

Let's assume the video bit_rate is 6000k and the audio bitrate is 192k, then we can convert the video with similar bitrate:

ffmpeg -i input.mp4 -c:v libx264 -b:v 6000k -c:a aac -b:a 192k output.mp4

• -c:v libx264: Use libx264 as the video codec
• -b:v 6000k: Set the video bit_rate to 6000k
• -c:a aac: Use aac as the audio codec
• -b:a 192k: Set the audio bit_rate to 192k

Merge Audio and Video Files

ffmpeg -i input.mp4 -i input.aac -c copy output.mkv

• -i input.mp4: Input video file
• -i input.aac: Input audio file
• -c: Copy

Cut Video

I wrote a nodejs wrapper of FFmpeg to cut video into clips with given timestamps in a config file, which I think is a better way to cut video.

# Cut by timestamp
ffmpeg -ss 00:00:30.0 -i input.wmv -t 00:00:10.0 -c copy output.wmv
# Cut by frame number
ffmpeg -ss 30 -i input.wmv -t 10 -c copy output.wmv

• Arguments' order is important, fail to keep them in the following order -ss <START_TIME> -i <INPUT_FILE> -t <END_TIME> [other] will result in getting a corrupted video. Official document on this matter.

• -ss: Start time

• -i: Input file

• -t: Duration

• -c: Copy content

• output.mp4: Output file

Merge Files in Directory

ffmpeg -f concat -safe 0 -i <(for f in *.mp4; do echo "file '$f'"; done) -c copy output.mp4

• -f: File format
• -safe: Safe mode
• -i: Input file
• -c: Copy
• output.mp4: Output file
• *.mp4: Files in directory
• -i <(for f in *.mp4; do echo "file '$f'"; done): Command to generate input file
• -c copy: Command to copy
• output.mp4: Output file

Remove Tag or Chapters

ffmpeg -i input.mp4 -map_metadata -1 -map_chapters -1 -vcodec copy -acodec copy output.mp4

• -map_metadata -1: Remove metadata
• -map_chapters -1: Remove chapters
• -vcodec copy: Copy video codec
• -acodec copy: Copy audio codec