====== FFMPEG ======

FFMPEG exemple script visual

Original article : https://lukaprincic.si/development-log/ffmpeg-audio-visualization-tricks
 
 
  Often one wants to share audio online, but it seems like video as a format has many more options: mastodon, twitter, facebook, youtube, all allow to upload video, but not only audio. Here are some ffmpeg tricks, how to add interesting video to your audio file, often autogenerated visuals. All the code is supposed to be used as one line without line-breaks.< 
 
====== Audio Vector Scope ======

<code csharp [enable_line_numbers="true",highlight_lines_extra="2"]>
ffmpeg -i INPUT_AUDIO.wav -filter_complex 
"[0:a]avectorscope=s=480x480:zoom=1.5:rc=0:gc=200:bc=0:rf=0:gf=40:bf=0,format=yuv420p[v]; 
 [v]pad=854:480:187:0[out]" 
 -map "[out]" -map 0:a 
-b:v 700k -b:a 360k 
OUTPUT_VIDEO.mp4
</code>

The code above creates a mp4 video file with a vectorscope nicely centered inside a 854×480 (480p) video. If you need a 1:1 video, just exclude the pad part:

<code csharp [enable_line_numbers="true",highlight_lines_extra="2"]>
ffmpeg -i INPUT_AUDIO.wav -filter_complex 
"[0:a]avectorscope=s=480x480:zoom=1.5:rc=0:gc=200:bc=0:rf=0:gf=40:bf=0,format=yuv420p[v]" 
 -map "[v]" -map 0:a 
-b:v 700k -b:a 360k 
OUTPUT_VIDEO.mp4
</code>
    

Documentation on ‘avectorscope’ filter is here: https://ffmpeg.org/ffmpeg-filters.html#avectorscope. One can play with zoom and other options to produce desired form.

====== Show waves ======

<code csharp [enable_line_numbers="true",highlight_lines_extra="2"]>
ffmpeg -i INPUT.wav -filter_complex 
"[0:a]showwaves=mode=line:s=hd480:colors=White[v]" 
-map "[v]" -map 0:a -pix_fmt yuv420p 
-b:a 360k -r:a 44100  OUTPUT.mp4
</code>

more options: http://www.ffmpeg.org/ffmpeg-filters.html#showwaves
 
======   Showspectrum ======

v
ffmpeg -i INPUT.wav  -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.mp4
</code>

Above code will create almost completely desaturated spectrum of the audio sliding from right to left. Again, there are various options to tweak, see here: https://ffmpeg.org/ffmpeg-filters.html#showspectrum-1
 

======  Histogram ======

 

<code csharp [enable_line_numbers="true",highlight_lines_extra="2"]>
ffmpeg -i INPUT.wav -filter_complex 
"[0:a]ahistogram=s=hd480:slide=scroll:scale=log,format=yuv420p[v]" 
 -map "[v]" -map 0:a 
 -b:a 360k OUTPUT.mp4
</code>
more options: http://www.ffmpeg.org/ffmpeg-filters.html#showwaves
 
 Static spectrogram====== 
 ======
Sometimes you want to just create a static image.

## create a spectrogram as a single frame
<code csharp [enable_line_numbers="true",highlight_lines_extra="2"]>
ffmpeg -i INPUT.wav -lavfi 
showspectrumpic=s=hd480:legend=0,format=yuv420p 
SPECTROGRAM.png
</code>
## add png to audio - you need to know the length of audio
<code csharp [enable_line_numbers="true",highlight_lines_extra="2"]>
ffmpeg -loop 1 -i SPECTROGRAM.png -i INPUT.wav 
-s hd480 -t 00:01:00 -pix_fmt yuv420p 
-b:a 360k -r:a 44100 OUTPUT.mp4
</code>
	
## create a spectrogram as a single frame
<code csharp [enable_line_numbers="true",highlight_lines_extra="2"]>
ffmpeg -i INPUT.wav -lavfi 
showspectrumpic=s=hd480:legend=0,format=yuv420p 
SPECTROGRAM.png
</code>
## add png to audio - you need to know the length of audio
<code csharp [enable_line_numbers="true",highlight_lines_extra="2"]>
ffmpeg -loop 1 -i SPECTROGRAM.png -i INPUT.wav 
-s hd480 -t 00:01:00 -pix_fmt yuv420p 
-b:a 360k -r:a 44100 OUTPUT.mp4
</code>

Above one is in two steps. More info here: http://www.ffmpeg.org/ffmpeg-filters.html#showspectrumpic
      
====== text overlays ======

<code csharp [enable_line_numbers="true",highlight_lines_extra="2"]>
ffmpeg -i video1.mp4 -i video2.mp4 \
  -filter_complex "[0:v:0] [0:a:0] [0:v:1] [0:a:1] concat=n=2:v=1:a=1 [v][a];
[v]drawtext=text='SOME TEXT':x=(w-text_w):y=(h-text_h):fontfile=OpenSans.ttf:fontsize=30:fontcolor=white[v]" \
  -map "[v]" -map "[a]" -deinterlace \
  -vcodec libx264 -pix_fmt yuv420p -preset $QUAL -r $FPS -g $(($FPS * 2)) -b:v $VBR \
  -acodec libmp3lame -ar 44100 -threads 6 -qscale 3 -b:a 712000 -bufsize 512k \
  -f flv "$YOUTUBE_URL/$KEY"
</code>
    
# Print file metadata etc.
     ffmpeg -i path/to/file.ext

# Convert all m4a files to mp3
     for f in *.m4a; do ffmpeg -i "$f" -acodec libmp3lame -vn -b:a 320k "${f%.m4a}.mp3"; done

# Convert video from .foo to .bar
 -g : GOP, for searchability 

<code csharp [enable_line_numbers="true",highlight_lines_extra="2"]>
ffmpeg -i input.foo -vcodec bar -acodec baz -b:v 21000k -b:a 320k -g 150 -threads 4 output.bar 
</code>

# Convert image sequence to video
<code csharp [enable_line_numbers="true",highlight_lines_extra="2"]>     ffmpeg -r 18 -pattern_type glob -i '*.png' -b:v 21000k -s hd1080 -vcodec vp9 -an -pix_fmt yuv420p -deinterlace output.ext
</code>

# Combine video and audio into 1 file
<code csharp [enable_line_numbers="true",highlight_lines_extra="2"]>     ffmpeg -i video.ext -i audio.ext -c:v copy -c:a copy output.ext
</code>

# Listen to 10 seconds of audio from a video file
 -ss : start time /   -t  : seconds to cut /   -autoexit : closes ffplay as soon as the audio finishes

<code csharp [enable_line_numbers="true",highlight_lines_extra="2"]>
ffmpeg -ss 00:34:24.85 -t 10 -i path/to/file.mp4 -f mp3 pipe:play | ffplay -i pipe:play -autoexit
</code>

-------
    
# Common switches
```bash
  -codecs       # list codecs
  -c:v              # video codec (-vcodec) - 'copy' to copy stream
  -c:a              # audio codec (-acodec)
 -fs SIZE         # limit file size (bytes)
```

# Bitrate

```bash
-b:v 1M          # video bitrate (1M = 1Mbit/s)
-b:a 1M          # audio bitrate
```

# Video

```bash
-aspect RATIO    # aspect ratio (4:3, 16:9, or 1.25)
-r RATE          # frame rate per sec
-s WIDTHxHEIGHT  # frame size
-vn              # no video
```

# Audio

```bash
-aq QUALITY      # audio quality (codec-specific)
-ar 44100        # audio sample rate (hz)
-ac 1            # audio channels (1=mono, 2=stereo)
-an              # no audio
-vol N           # volume (256=normal)
```

## Example
### Ringtone conversion using ffmpeg

```bash
ffmpeg -i foo.mp3 -ac 1 -ab 128000 -f mp4 -acodec libfaac -y target.m4r
```

### To web

# no audio
<code csharp [enable_line_numbers="true",highlight_lines_extra="2"]>
ffmpeg -i input.mov -vcodec h264   -an -strict -2 output.mp4
ffmpeg -i input.mov -vcodec libvpx -an output.webm
</code>

<code csharp [enable_line_numbers="true",highlight_lines_extra="2"]>
ffmpeg -i input.mov -vcodec h264 -acodec aac -strict -2 output.mp4
ffmpeg -i input.mov -vcodec libvpx -acodec libvorbis output.webm
</code>

```html
<video width="320" height="240" controls>
  <source src="movie.mp4" type='video/mp4'></source>
  <source src="movie.webm" type='video/ogg'></source>
</video>
```
    
  
#ffmpeg generate overlay complex filter for audio with background image
<code csharp [enable_line_numbers="true",highlight_lines_extra="2"]>
    ffmpeg -y -i input.mp3 -loop 1 -i background.png \
    -filter_complex "[0:a]showwaves=s=1280x720:mode=line,colorkey=0x000000:0.01:0.1,format=yuva420p[v];[1:v][v]overlay[outv]" \
    -map "[outv]" -pix_fmt yuv420p -map 0:a -c:v libx264 -c:a copy -shortest output.mp
</code>

[https://www.youtube.com/watch?v=zKYzJ_bEJVo](https://www.youtube.com/watch?v=zKYzJ_bEJVo)
<code csharp [enable_line_numbers="true",highlight_lines_extra="2"]>
ffmpeg -y -i audio.mp3 -loop 1 -i image.jpg \
    -filter_complex "[0:a]showwaves=s=1280x175:colors=Yellow:mode=line,format=yuv420p[v];[1:v][v]overlay=0:200[outv]" \
    -map "[outv]" -pix_fmt yuv420p -map 0:a -c:v libx264 -c:a copy -shortest output9.mp4
</code>
    
[https://www.youtube.com/watch?v=1htjI7YSNZo](https://www.youtube.com/watch?v=1htjI7YSNZo)
<code csharp [enable_line_numbers="true",highlight_lines_extra="2"]>
ffmpeg -y -i audio.mp3 -loop 1 -i image.jpg \
    -filter_complex "[0:a]showwaves=s=1280x720:mode=line,colorkey=0x000000:0.01:0.1,format=yuva420p[v];[1:v][v]overlay[outv]" \
    -map "[outv]" -pix_fmt yuv420p -map 0:a -c:v libx264 -c:a copy -shortest output1.mp4
</code>
[https://www.youtube.com/watch?v=H5dCKuN9Ius](https://www.youtube.com/watch?v=H5dCKuN9Ius)


<code csharp [enable_line_numbers="true",highlight_lines_extra="2"]>
ffmpeg -y -i audio.mp3 -loop 1 -i image.jpg \
    -filter_complex "[0:a]showwaves=s=1280x175:colors=White:mode=p2p,format=yuv420p[v];[1:v][v]overlay=0:200[outv]" \
    -map "[outv]" -pix_fmt yuv420p \
    -map 0:a -c:v libx264 -c:a copy -shortest output12.mp4
</code>