Add Audio to Video

Attach an audio track to a video, either replacing the existing audio entirely or mixing it with the audio already present in the video.

When to use

• Add a voiceover or narration to a silent or muted video clip.
• Replace a shaky on-camera audio track with a studio-recorded version.
• Mix in background music alongside the original dialogue/audio.

Inputs & outputs

Input modality	Video file (URL) + Audio file (URL)
Output modality	Video file (GCS URL)
Max input duration	30 min
Max input size	5 GB

Parameters

Param	Required	Description
mode	no (default replace)	replace drops the video's original audio and uses the new track; mix combines both audio tracks.
shortest	no	When true, trims the output to the length of the shorter of the two inputs.

Examples

Replace the original audio track

{
  "type": "video.add_audio",
  "input": { "video_url": "gs://infery-prod-media/example/input.mp4", "audio_url": "gs://infery-prod-media/example/voiceover.mp3" },
  "params": { "mode": "replace" }
}

Mix a music bed under the existing audio

{
  "type": "video.add_audio",
  "input": { "video_url": "gs://infery-prod-media/example/input.mp4", "audio_url": "gs://infery-prod-media/example/music.mp3" },
  "params": { "mode": "mix", "shortest": true }
}

Related capabilities

• video.extract_audio — pull the existing audio track out before replacing it
• video.trim — trim the video or audio to matching lengths beforehand
• video.pipeline — chain add_audio with other operations in one step

{
  "mode": "replace"
}