Useful FFMPEG Commands

FFMPEG Commands

Record HLS Stream from Beginning (or as far back as segments go)

ffmpeg -live_start_index -99999 -i 'http://domain.com/hls/master.m3u8' -c copy output.mkv

Timeslip one Decklink to Another

ffmpeg -f decklink -audio_input embedded -channels 16 -i 'DeckLink SDI (1)' -vcodec libx264 -crf 25 -preset ultrafast output.mkv

ffmpeg -re -i output.mkv -f decklink -pix_fmt uyvy422 'DeckLink SDI (2)'

Mirror HLS to directory via FTP: 

ffmpeg -i http://remote.com/hls/segs/master.m3u8 -c:a copy -hls_time 9 -hls_list_size 3 -hls_wrap 0 -start_number 0 -hls_allow_cache 0 -segment_list_flags +live -hls_flags delete_segments ftp://[email protected]:[email protected]/master.m3u8

Split Video By Silence

ffmpeg -i input.mkv -filter_complex "[0:a]silencedetect=n=-90dB:d=0.3[outa]" -map [outa] -f s16le -y /dev/null |& F='-aq 70 -v warning' perl -ne 'INIT { $ss=0; $se=0; } if (/silence_start: (\S+)/) { $ss=$1; $ctr+=1; printf "ffmpeg -nostdin -i input.mkv -ss %f -t %f $ENV{F} -y %03d.mkv\n", $se, ($ss-$se), $ctr; } if (/silence_end: (\S+)/) { $se=$1; } END { printf "ffmpeg -nostdin -i input.mkv -ss %f $ENV{F} -y %03d.mkv\n", $se, $ctr+1; }' | bash -x https://stackoverflow.com/questions/36074224/how-to-split-video-or-audio-by-silent-parts#comment63050906_36077309

SRT to Decklink

ffmpeg -i srt:remote.com:port?mode=listener -f lavfi -i anullsrc=sample_rate=48000:channel_layout=mono -filter_complex "join=inputs=3:channel_layout=octagonal:map=0.0-FL|0.1-FR|1.0-FC|1.1-BL|2.0-BR|2.0-BC|2.0-SL|2.0-SR[a]" -map 0:v -map "[a]" -f decklink -pix_fmt uyvy422 -s 1920x1080 -r 60000/1001 -ar 48000 "DeckLink Duo (2)" https://discord.com/channels/494428283094564864/494428766525718528/939278974410952745

Stream Static File to Youtube

You may need to update the video parameters to meet newer Youtube recommendations for stream ingest {.is-info}

ffmpeg -i "input.mov" -deinterlace -vcodec libx264 -pix_fmt yuv420p -preset medium -r 30 -g 60 -b:v 2500k -acodec libmp3lame -ar 44100 -threads 6 -qscale 3 -b:a 712000 -bufsize 512k -f flv "rtmp://a.rtmp.youtube.com/live2/key"

Stream Local File to Facebook

You may need to update the video parameters to meet newer Facebook recommendations for stream ingest {.is-info}

ffmpeg -i "input.mov" -deinterlace -vcodec libx264 -pix_fmt yuv420p -preset medium -r 30 -g 60 -b:v 2500k -acodec aac -ar 44100 -threads 6 -qscale 3 -b:a 712000 -bufsize 512k -f flv "rtmp://rtmp-api.facebook.com:80/rtmp/key"

Output file with timestamp record of every blackframe

ffmpeg -i "file.mp4" -t 00:00:40 -filter_complex "[0]trim=start_frame=0:end_frame=1[c];[c][0]blend=all_mode=difference,blackframe=amount=98:threshold=32" -f null - 2>&1 | grep blackframe > output.txt

Use "difference" blend mode to find all subsequent occurances of frame

This can be useful to find every instance of where a video loops if given a single still frame by matching future occurances of that single frame (which are written to output.txt) ffmpeg -i "input.mp4" -t 00:00:40 -filter_complex "[0]trim=start_frame=0:end_frame=1[c];[c][0]blend=all_mode=difference,blackframe=amount=98:threshold=32" -f null - 2>&1 | grep blackframe > output.txt

Create Visual Audio Spectrum from Input File

ffmpeg -i input.mkv -filter_complex "[0:a]showspectrum=s=854x480:mode=combined:slide=scroll:saturation=0.2:scale=log,format=yuv420p[v]" -map "[v]" -map 0:a -b:v 700k -b:a 360k output.mkv

Capture raw DV video over firewire and save to file (Mac only)

ffmpeg -f avfoundation -capture_raw_data true -i "DV-VCR" -c copy -map 0 -f rawvideo capture.dv

To convert to Prores LT with proper color metadata: ffmpeg -i capture.dv -c:v prores_ks -profile:v 1 -colorspace smpte170m -color_primaries smpte170m -color_trc 1 -c:a copy -movflags +write_colr capture_prores.mov {.is-info}