Video Audio Merge (Wiro Native)

## Overview Video Audio Merge combines one video file and one audio file into a single finished video. It keeps the original visuals and writes a new soundtrack. You can either replace the original audio or mix the new track over it. This helps when you recorded video and sound separately and need a clean export without manual editing. ## What you can build - Add a voiceover track to a screen recording - Replace noisy camera audio with a clean microphone recording - Add background music to a product demo - Create a dubbed version of a clip in another language - Turn a silent clip into a shareable video with sound ## Inputs - One video file that will keep its visuals in the final result. Use a standard container like MP4 when possible. - One audio file to place on the video. Use common formats like MP3 or WAV. - A choice for how to handle the video’s original sound: fully replace it, or mix both tracks together. - An optional loudness setting for the added audio, set as a percentage from 0% to 500%. - In mix mode, an optional loudness setting for the video’s own sound, also from 0% to 500%: 0% keeps only the added track. - An optional switch to repeat a short audio track until it spans the full video. - An optional switch to end the export when the shorter track ends, or keep the full video length. - An optional loudness target in LUFS that normalises the finished soundtrack, such as -14 for YouTube, TikTok and Instagram. ## Outputs The model returns one merged video file you can download. The visual track comes from the input video. The audio track comes from your selected mode. In replace mode, the original soundtrack is removed. In mix mode, the output contains a single blended soundtrack that includes both sources. With a loudness target, the finished soundtrack is measured and brought to that loudness with one even gain, and its peaks stay under -1.5 dBTP. ## Recommended settings - Use **Replace** when the original audio is unusable or you want only the new soundtrack. - Use **Mix** for background music under existing speech. - In **Mix**, set the original volume to **50%** to keep the video’s own sound effects or room tone under the new track. - Start the added-track volume at **100%** to keep it unchanged. - Set the added-track volume to **50%** for quieter background music. - Use **Loop audio = on** for short music beds or ambience tracks. - Keep **End on the shorter track = on** when you must avoid trailing silence. - Turn **End on the shorter track = off** when you must keep full video timing. - Set **Loudness = -14 LUFS** on the last merge of a video you publish on social platforms: they play everything at about -14 and never turn quieter videos up. ## Limitations - The model does not auto-sync a voiceover to lip movement. It starts both tracks at time 0. - Mix mode can cause clipping if both tracks are loud. Lower the added-track or original volume if you hear distortion. - Looping repeats the audio from the start. It does not beat-match or create smooth crossfades. - If you keep the full video length and the audio ends early, the rest of the clip may be silent. - Variable frame rate videos, corrupted MP4s, or unusual codecs can fail or produce timing issues. - Low-quality audio, heavy compression, or background noise will still be present after merging. ## Safety & compliance - Only upload audio and video you own or have rights to use. - Get consent before adding someone’s voice to a video you publish. - Don’t use this tool to create deceptive edits that misrepresent what someone said. - Follow your platform rules for copyrighted music, trademarks, and personal data.