> ## Documentation Index > Fetch the complete documentation index at: https://docs.decktalk.app/llms.txt > Use this file to discover all available pages before exploring further. # Add a clip section > Open a DeckTalk video with a clip of your own, with its own audio, using the commented section 0 in the scaffold, a slate when the file is missing, and a dip to black at the cut. A clip section is a video file of your own that plays in the sequence with its own audio. DeckTalk does not narrate it, and it scales and pads the picture to the frame size. The scaffold ships with a commented-out clip section so that a video can open on camera before the first slide. Remove the leading `# ` from the five lines of the clip section, and set the transition so that the cut out of the clip dips to black. ```toml decktalk.toml theme={null} [[section]] number = 0 title = "On camera" clip = "media/open.mp4" slate_seconds = 6 # a titled slate plays for this long when the file is missing [transition] dips = [[0, 1]] ``` `dips` lists the boundaries that fade through black as `[from, to]` pairs of section numbers. The scaffold sets it to `[]`, which is straight cuts everywhere. Leave the key out to dip at every cut. Every `[[section]]` needs a heading in the script, so add `## 0. On camera` above section 1. Nothing under it is spoken, because narration skips clip sections, so the body can be a stage direction that reminds you what plays there. ```md script.md theme={null} ## 0. On camera [Your clip at media/open.mp4 plays here, with its own sound.] ## 1. Open ``` Put the video at `media/open.mp4`. Git ignores `media/*.mp4` by default. A clip that is not 1920 by 1080 is scaled to fit and padded with black, and a clip with no audio track plays silent with a warning. The file does not have to exist yet. A missing clip becomes a titled slate for `slate_seconds`, with the section title and the path where the file belongs, so the project builds before every asset does. The `--strict` flag on `build` or `assemble` turns a missing clip into an error instead. ```console theme={null} decktalk build --silent ``` ```text theme={null} section 00: media/open.mp4 missing; slate for 6s (drop your clip at that path) [cut ] 00 slate -> 00-section.mp4 (6.000s) [cut ] 01 01-scene.webm (lead 1.4s trimmed) -> 01-section.mp4 (10.160s) ``` The status report lists the clip with the others. ```text theme={null} 00 clip media/open.mp4 cut 01 deck/index.html?scene=1 rec cut ``` ## Where a clip may sit The narration is one continuous track that begins with the first page section, and each page section is cut to its own span in that track. A clip therefore belongs before the first page section or after the last one. A clip placed between two page sections plays while the narration of the following section is already running, so that section's words and picture no longer agree. Open on a clip, close on a clip, or cut a clip's audio into the narration by hand, but do not put one in the middle. ## The clip's sound The clip's own audio is mixed in at the section start, trimmed to its picture, and faded over twenty milliseconds at both ends so that a cut never clicks. The underscore ducks under a clip as it ducks under speech. [Sound](/concepts/sound) describes the mix. ## Next [decktalk.toml](/reference/decktalk-toml#section) lists every key of a clip section, and [Rebuild one section](/guides/rebuild-one-section) explains that replacing the clip file needs only `decktalk assemble`, since a clip is never recorded.