cetinajero/ffmpeg.md

## ffmpeg.md

      
    Raw
  

              ffmpeg.md
            
          
    Usefull ffmpeg commands

General options

List codecs
ffmpeg -codecs | grep -i sub
Quiet output:
ffmpeg -i input.avi -loglevel fatal -stats output.mp4
Search for more streams by analyzing more video:
ffmpeg -i input.avi -analyzeduration 300M -probesize 300M output.mp4
Previewing with ffplay

ffplay -i input.avi -vf crop=ih
Control size of the output

Define specific codecs
ffmpeg -i input.avi -c:v:0 h264 -c:a:0 aac output.mp4
Resize video mantaining aspect ratio
ffmpeg -i input.avi -vf scale=-1:720 output.mp4
Define bitrate
ffmpeg -i input.avi -vcodec h264 -b:v:0 250k -acodec aac -b:a:0 128k output.mp4
Export only a part of the video

Export only the first 30 seconds:
ffmpeg -i input.avi -t 30 output.mp4
Export only the defined section:
ffmpeg -i input.avi -ss 00:04:28 -to 00:55:06 output.mp4
Note: If speed is important... use -c copy to avoid encoding.
Map streams

Useful for removing and reordering streams:

Identifier: (source:type:number)

ffmpeg -i input.avi -map 0:v:0 -map 0:a:2 -map 0:a:0 output.mp4
Crop a video

Use cropdetect to auto-detect crop size:
ffplay -i input.avi -vf cropdetect
Use the crop filter:

crop=w:h:x:y

These 3 are the same:
ffmpeg -i input.avi -vf crop=640:360:1280:250 output.mp4
ffmpeg -i input.avi -vf crop=16*10*4:9*10*4:1920-16*10*4:250 output.mp4
ffmpeg -i input.avi -vf crop=iw/3:ih/3:iw-ow:250 output.mp4
The filter will automatically center the crop if x and y are omitted:

crop=w:h

Crop 10 pixels from the top, and 10 from the bottom:
ffmpeg -i input.avi -vf crop=iw:ih-2*10 output.mp4
Note: If speed is important... use -c:a copy to avoid audio encoding.
Adjust FPS

ffmpeg -i input.avi -vf fps=10 output.mp4
Multiplex three independent sources

ffmpeg -i input.avi -i left.wav -i right.wav -map 0 -map 1 -map 2 -c copy output.mp4
Concatenate three independent sources

Audio & Video
ffmpeg -i input1.mp4 -i input2.mkv -i input3.mov -filter_complex "[0:v:0][0:a:0][1:v:0][1:a:0][2:v:0][2:a:0]concat=n=3:v=1:a=1[v][a]" -map "[v]" -map "[a]" output.mp4
Just audio
ffmpeg -i input1.wav -i input2.wav -i input3.wav -i input4.wav -i input5.wav -i input6.wav -filter_complex "[0:a:0][1:a:0][2:a:0][3:a:0][4:a:0][5:a:0]concat=n=6:v=0:a=1 [a]" -map "[a]" output.mp3
Extirp a section from an audio

REMOVE_FROM="00:00:06"
REMOVE_TO="00:00:08.8"

ffmpeg -i input.mp3 -c copy -to $REMOVE_FROM input-temp1.mp3; \
ffmpeg -i input.mp3 -c copy -ss $REMOVE_TO input-temp2.mp3; \
ffmpeg -i input-temp1.mp3 -i input-temp2.mp3 \
       -filter_complex "[0:a:0][1:a:0]concat=n=2:v=0:a=1 [a]" \
       -map "[a]" output.mp3; \
rm input-temp*.mp3;
Convert audio 5.1 to stereo

Convert multichannel audio to stereo (Audio channels)
ffmpeg -i input.avi -ac:a:0 2 output.mp4
Define specific levels of audio channels to stereo (Audio filter)

FL/FC/BL: Front/Center/Back Left

ffmpeg -i input.avi -af "pan=stereo|FL=FC+0.30*FL+0.30*BL|FR=FC+0.30*FR+0.30*BR" output.mp4
Adjust volume

Analyze the file using the volumedetect filter
ffmpeg -i input.mp3 -af volumedetect -f null - 2>&1 | grep volume:
Adjust the volume by 10% or 5dB down
ffmpeg -i input.mp3 -af "volume=0.9" output.mp3

# or

ffmpeg -i input.mp3 -af "volume=-5dB" output.mp3
Fade in and fade out effects

Start with a black screen and fade into full view over 3 seconds
ffmpeg -i input.avi -vf "fade=t=in:st=0:d=3" output.mp4
Start fading to black over 5 seconds at the 10-second mark
ffmpeg -i input.avi -vf "fade=t=out:st=10:d=5" output.mp4
The audio file will start at a low volume and fade in to full over 5 seconds.
ffmpeg -i input.mp3 -af "afade=t=in:st=0:d=5" output.mp3
The audio file will start fading to zero volume over 5 seconds starting at the 15-second mark.
ffmpeg -i input.mp3 -af "afade=t=out:st=15:d=5" output.mp3
You can apply both fade in and out effects at the same time, to avoid having to re-encode twice.
ffmpeg -i input.avi -vf "fade=t=in:st=0:d=3,fade=t=out:st=10:d=5" output.mp4
Slow motion / Speed up / Timelapse

Slow mo:
ffmpeg -i input.avi -vf "setpts=PTS/0.5" -af "atempo=0.5" output.mp4
Speed up:
ffmpeg -i input.avi -vf "setpts=PTS/2" -af "atempo=2.0" output.mp4

NOTE: The atempo filter is limited to using values between 0.5 and 2.0 (so it can slow it down to no less than half the original speed, and speed up to no more than double the input). If you need to, you can get around this limitation by stringing multiple atempo filters together. The following with quadruple the audio speed:

ffmpeg -i input.avi -vf "setpts=PTS/4" -af "atempo=2.0,atempo=2.0" output.mp4
Timelapse:

Speed: 60x (1 hour in 1 min, 1 min in 1 sec)
Audio: No

ffmpeg -i input.avi -vf "setpts=PTS/60" -an output.mp4
Convert DVD VIDEO_TS folder to video format

cat ./VIDEO_TS/*.VOB | ffmpeg -i - output.mp4
Download Streaming videos from Salesforce @ Amazon CloudFront

ffmpeg -i rtmp://s39mvapi4g5wnh.cloudfront.net/cfx/st/flv:VideosPortalNuevo/Finanzas/Revaluacion_Moneda_Extranjera -profile:v high -preset slow -threads 0 Revaluacion_Moneda_Extranjera.mp4
Convert a RTSP url to RTMP url

ffmpeg -i "[your rtsp link]" -f flv -r -s -an "[Your rtmp link]"
Sync subtitles

http://subshifter.bitsnbites.eu
Download YouTube files (youtube-dl)

MP3 Playlist

youtube-dl --extract-audio --audio-format mp3 -i -o "%(title)s.%(ext)s" https://www.youtube.com/watch?list=RDQMYgJ4UDCmSlA
MP4 Video

youtube-dl -f 'bestvideo[ext=mp4]+bestaudio[ext=m4a]/mp4' -o "%(title)s.%(ext)s" https://www.youtube.com/watch?v=R8wG1W1TPgw
Referred Video

youtube-dl -f 'bestvideo[ext=mp4]+bestaudio[ext=m4a]/mp4' -o "%(title)s.%(ext)s" --referer https://www.taitradio.com/products/tait-enable-network-management/enablemonitor https://player.vimeo.com/video/106990265
Split an MP3 file by detecting silent parts

mp3splt is a program for splitting mp3s without re-encoding that has a silence detector (among other detection methods).
Usage with the Silence mode (-s):
mp3splt -s input.mp3