scripts to do media conversion stuff, mostly with ffmpeg

Sometimes you want an empty audio file, for example if you listen to music before going to bed.

The ones online, like in this repo are pretty big. The bottlenecks are always the minimum quality settings that codecs support, as they really didn't intend to be used for this purpose.

So I found the smallest possible audio format!

• AAC codec
• 4000Hz "input" samplerate
• 1kHz bitrate
• mono channel

A 24h long silent audio is under 5MB, which is not great, but better than everything else!

I tested opus, wav, raw and mp3. All either have higher minimum quality settings, or don't compress as well.

If you find a way to make them even smaller, please share!

opus is the successor to vorbis and a really great, lossy codec that (for me) preserves audible audio 100%.

You can test how much opus takes from your beloved flac files, by doing this:

1. Get Audacity or Tenacity
2. Configure that outdated garbage app to read your files
3. Compress a flac or wav file with ogg opus
4. Load the lossy file into audacity, load the lossless file as seconds track
5. Select the track with the compressed file, go to "Effects" "Special" and "Invert"
6. Press the "Play" button

You will only hear what is left in the lossless file, but not in the lossy one. While AAC and mp3 remove noticeable things, I wasn't able to hear anything with opus.

• .mpd to opus
• .exo and .video to m4a

These are strange file formats for IOS or the Android EXO media player. They contain AAC or OPUS audio.

The conversion does not use re-encoding, just writes the audio streams into a different container, making them work in normal players. Thus the conversion is very quick.

• patreon .mp3 to m4a

Patreon videos can be extracted from the browser, using Firefox addons like this one. But they are separated into snippets, have broken metadata and more.

ffmpeg is able to extract the AAC audio stream from the actual MP3-TS files, concatenate them and write them into an m4a container.

There are generic mp3concat and mp4concat scripts there.

They are useful if you download videos (above Firefox Addon) and they are in small snippets.

The conversion is really fast as they are just written into the same file, not converted. It works if the videos or music files are normal. For special files, open an issue or use above scripts.