There are times when the audio on a video needs to be replaced. Here filters are not even needed to replace audio but the use of -map becomes important to understand: Here the video from the first input and the audio from the second input is mapped to the output. Challenge: Using the same concepts in the above […]
Adding an additional audio source on top of the audio already in a video can be accomplished with the amix filter. This might be useful for adding background music to a commentary video. The command is as follows: A common issue that comes up with amix is the volume of one input over powers the second. Setting the louder […]
Although this next command isn’t exactly a filter, it’s still useful to know how to remove or mute, audio in an MP4. Below is the quickest way to remove audio from any form of video using the -an option: Tip: -an indicates no audio output. Documentation https://ffmpeg.org/ffmpeg-all.html#Examples
A high-pass filter is an audio filter that cuts off frequencies that are lower than the desired cutoff frequency. This is often used to cut out bass from an audio source while leaving the treble side of the audio. The filter in FFmpeg is called highpass and is used by setting the desired cut off […]
A low-pass filter is an audio filter that cuts off frequencies that are higher than the desired cutoff frequency. This filter is popular in music production as it can be used to soften audio or remove undesired noise. With FFmpeg the filter lowpass is used by setting the desired cutoff frequency in Hz. In this […]
Flitevox or Flitelib is an open source small run time speech engine. Pass it text and create an audio file with a robot saying it. Really cool and useful for some projects. Flitelib is not a native filter available in FFmpeg build nor inside the source. Although the documentation states that –enable-libflite is required for […]
Tip: You’ll need to enable –enable-libflite for this filter to work. Generating text to speech is a great feature to have locally on a computer. From using it in a YouTube video to making memes on Twitter, once you learn this filter, you’re creating content at new speeds. There are two methods to set text […]
FFmpeg also has the ability to generate sounds or tones natively. With the right kind of scripting you could make chiptune like music straight from the terminal. In this example, generating a single 2000Hz sound for 10 seconds is enough for now: A new argument, lavfi, needs to be introduced here as this time there […]
Changing the pitch of an audio track means the tempo stays the same but the audio pitch increases/decreases. There isn’t a native way to change the pitch without also changing the playback speed. Luckily, chaining the atempo and asetrate filters together can achieve this effect. In this example, the pitch of the audio decreases by […]
Changing the tempo of an audio file is easy with atempo. This filter only accepts one value, a number between 0.5 and 100. In this example, the audio tempo is increased by 50%: So how does 1.50 equal 50%? That’s because any value above 1.0 will increase the tempo and any value below 1.0 will […]