Configuration

Tuning is everything about how DeckTalk renders that does not change from one presentation to the next. It comes from three layers, and each layer overrides the one before it.

The defaults on this page.
A table of the same name in the project’s decktalk.toml. For example, [video] with preset = "veryfast" changes the x264 preset for that project.
An environment variable named DECKTALK_<SECTION>_<FIELD>. For example, DECKTALK_VIDEO_PRESET=veryfast changes it for one shell. A list field such as probe_delays takes comma-separated values.

A few command-line flags override all three for a single run: --preset, --crf, --settle, and --model. Content that changes per presentation is the project document, not tuning. Sections, the voice, mix levels, and soundscape prompts live in the same file under their own tables, and the project file describes them. Secrets live only in .env.

You rarely need this page. The scaffold builds with every default. Reach for [video] when drafts feel slow, and for [verify] when a deliberately subtle reveal fails the cue check.

`[video]`

Frame size and encoding of every recording and of the final mp4. Environment variables start with DECKTALK_VIDEO_.

Field	Type	Default	Notes
`width`	`int`	`1920`
`height`	`int`	`1080`
`fps`	`int`	`30`
`preset`	`str`	`'medium'`	x264 preset; veryfast for drafts
`crf`	`int`	`18`
`audio_bitrate`	`str`	`'192k'`
`sample_rate`	`int`	`44100`
`channels`	`int`	`2`
`slate_color`	`str`	`'0x0e1116'`	plain frame when a slate cannot be rendered

`[narration]`

How the script is turned into audio. Environment variables start with DECKTALK_NARRATION_.

Field	Type	Default	Notes
`model`	`str`	`'eleven_multilingual_v2'`
`output_format`	`str`	`'mp3_44100_128'`
`mp3_bitrate`	`str`	`'128k'`
`words_per_minute`	`int`	`140`	pacing estimate shown in tables
`silent_words_per_minute`	`int`	`150`	—silent placeholder pacing
`lead_break_seconds`	`float`	`0.7`	opens the first spoken section
`direction_break_seconds`	`float`	`0.7`	pause where a bracketed direction sat
`tail_break_seconds`	`float`	`0.35`	requested at the end of every section
`min_tail_seconds`	`float`	`0.35`	guaranteed silence after the last word
`tail_slack_seconds`	`float`	`0.05`	extra padding added when the tail is short
`context_chars`	`int`	`1500`	previous_text / next_text sent for prosody continuity
`timeout_seconds`	`int`	`180`

`[record]`

Headless Chromium recording. Environment variables start with DECKTALK_RECORD_.

Field	Type	Default	Notes
`settle_seconds`	`float`	`0.5`	after load, before narration t=0
`min_lead_seconds`	`float`	`1.5`	t=0 never comes sooner than this after the recorder starts
`color_scheme`	`str`	`'light'`
`shot_settle_ms`	`int`	`400`	wait before a review screenshot

`[align]`

Finding narration t=0 in a recording, and the recording sanity check. Environment variables start with DECKTALK_ALIGN_.

Field	Type	Default	Notes
`scan_seconds`	`float`	`4.0`
`fallback_first_paint_seconds`	`float`	`1.1`
`magenta_luma_min`	`float`	`70`
`magenta_luma_max`	`float`	`140`
`magenta_chroma_min`	`float`	`165`
`painted_ymax`	`float`	`60`	something is drawn
`painted_yavg_max`	`float`	`120`	and it is not a white flash
`black_ymax`	`float`	`40`	check: a frame darker than this is “black”
`truncated_slack_seconds`	`float`	`0.5`

`[audio]`

Mix mechanics. Levels are per project (decktalk.toml [mix]). Environment variables start with DECKTALK_AUDIO_.

Field	Type	Default
`duck_ramp_seconds`	`float`	`0.5`
`ambience_ramp_seconds`	`float`	`1.0`
`ambience_pad_seconds`	`float`	`0.5`
`marker_mute_ramp_seconds`	`float`	`0.04`
`marker_boost_ramp_seconds`	`float`	`0.3`
`limiter`	`float`	`0.95`

`[verify]`

Checks on the assembled mp4. Environment variables start with DECKTALK_VERIFY_.

Field	Type	Default	Notes
`after_dip_seconds`	`float`	`0.2`
`lead_seconds`	`float`	`0.1`	the reference frame sits this long before the cue
`probe_delays`	`tuple[float, ...]`	`(0.7, 1.5)`	seconds after the cue; the later one catches slow reveals
`diff_level`	`int`	`40`	luma steps a pixel must change to count
`min_changed_percent`	`float`	`0.1`	share of the frame the best probe must change
`min_margin_percent`	`float`	`0.1`	and by how much it must beat the control span
`visible_ymax`	`float`	`60`
`probe_width`	`int`	`480`
`probe_height`	`int`	`270`

`[elevenlabs]`

Environment variables start with DECKTALK_ELEVENLABS_.

Field	Type	Default
`api_base`	`str`	`'https://api.elevenlabs.io/v1'`
`sound_model`	`str`	`'eleven_text_to_sound_v2'`
`music_model`	`str`	`'music_v2'`
`music_bitrate`	`str`	`'192k'`
`max_music_chunk_seconds`	`int`	`300`
`music_crossfade_seconds`	`int`	`2`
`ambience_seconds`	`float`	`25.0`
`ambience_prompt_influence`	`float`	`0.3`
`sfx_seconds`	`float`	`0.5`
`sfx_prompt_influence`	`float`	`0.5`
`timeout_seconds`	`int`	`600`

Get started

Concepts

Reference

Help

`[video]`

`[narration]`

`[record]`

`[align]`

`[audio]`

`[verify]`

`[elevenlabs]`

​[video]

​[narration]

​[record]

​[align]

​[audio]

​[verify]

​[elevenlabs]

`[video]`

`[narration]`

`[record]`

`[align]`

`[audio]`

`[verify]`

`[elevenlabs]`