Audio Joiner: Stitch Audio

Audio joiner for shaping clips into a sequence or layering a second lane beneath them. Stitch Audio puts waveform trimming and the choice between Join and Mix at the centre of your project.

▶ ZOOM IN AND TRIM EACH CLIP
• Open Edit clip to see its waveform. Pinch to zoom, pan across the audio and drag either edge to set the trim boundaries.
• Nudge the start or end by 10 ms, or enter a time in seconds. Tap the waveform to move the preview position, then use Preview to listen from there.
• Give each clip a chapter name and adjust its gain, fade in and fade out. Peak normalize adjusts signal level; RMS match is labelled approximate because signal level and perceived loudness are different.

▶ JOIN OR MIX YOUR SOUND
• Join places clips in sequence. Move a clip earlier or later to change the order.
• Tap a diamond to choose Hard cut, Gap or Crossfade for that transition. Set the gap or crossfade duration in seconds, then preview the audio around the join before saving.
• Mix layers a second lane beneath the main sequence. Add second lane, edit its clip and set its volume and start time separately from the main lane volume.
• Crossfades are shortened to fit when trims, order or output rate change. The timeline recalculates clip positions and project duration from the current edits.

▶ EXPORT AUDIO AND A CHAPTER LIST
• Choose an output sample rate of 44.1 or 48 kHz and select Mono or Stereo before exporting. Imported audio is resampled to the project rate.
• Render M4A with AAC-LC encoding or 16-bit WAV. Share audio or use Save audio file to keep a copy at a destination you choose.
• The Chapters tab turns clip names and their timeline start times into a timestamped text list. Copy chapter list, Share chapter list or Save chapter list as a text file.
• Save a project to return to its clips and transitions. Imported source files are copied into app storage. Project backups include audio media and can be restored from their parts and manifest.

▶ GOOD TO KNOW
• Projects can be up to 3 hours long. Each trimmed clip must be at least 0.1 seconds. A crossfade cannot exceed half the length of the shorter adjacent clip.
• Input support depends on the decoders available on your device. Audio processing runs locally; a first preview of a long source can take time to prepare.
• The chapter list is a separate text file; it is not embedded in the exported audio.
• Keep the app open while exporting. If an export is interrupted, export again. Large projects need temporary storage, and WAV export is blocked when it would exceed the RIFF size limit.
• Exports and backups are created in the app and may be cleaned up. Copies shared or saved elsewhere are kept where you put them.
• Import uses the file picker. The app does not record audio or request microphone access.