wehub-resource-sync
8.3 KiB
Exporting Videos and Image Sequences
TL;DR
You can use TiXL to render your project as a video or image sequence:
- Select (or pin) an image operator like [RenderTarget] in the Output Window.
- Use the output window's resolution selector to set your output resolution.
- Open Render To File — the sliders icon in the output window's toolbar, or via the main menu.
- Pick a Range, Codec, and output path, then press Render.
The filename extension follows the codec automatically (.mp4, .mov, .mkv), so you don't have to set it by hand.
Settings
The Render To File window groups its settings into three sections (and a help button in the panel header links back to this page):
- Source — the Range (Custom / Loop / Soundtrack / Continuous), the Scale unit (bars, seconds, frames), FPS, the Resolution Scale multiplier, and the Motion Blur override.
- Format & Quality — render mode (video or image sequence), Codec, Bitrate, and audio export.
- Output Target — the folder, filename, and auto-increment options.
Every parameter has a small (?) marker next to it — hover it for a one-line explanation. The footer shows a one-line summary with a rough size and render-time estimate.
About FFmpeg
FFmpeg is the open-source engine that does the actual video encoding — it turns the frames TiXL renders into a finished .mp4, .mov, or .mkv file. It is the same technology that powers most video software.
FFmpeg comes built into TiXL. There is nothing to install, download, or configure, and TiXL never has to call out to a separate program on your computer — exporting just works out of the box. The version TiXL ships uses license-friendly components, so the videos you export are free to use in your own projects.
Codecs
A codec is the recipe used to compress the video. TiXL offers several, because no single one is best for everything — some are made for sharing online, some for editing, some for live VJ playback.
Every codec can carry an AAC audio track when Export Audio is on. H.264 and HEVC use your graphics card's hardware encoder (NVIDIA NVENC, Intel Quick Sync, or AMD AMF) when one is available, which is much faster; otherwise TiXL falls back to a slower software encoder. The small line under the Codec dropdown tells you which one your machine will use.
| Codec | File | Best for | Notes & limitations |
|---|---|---|---|
| H.264 | .mp4 |
The safe, compatible default — plays everywhere | 8-bit; quality set by Bitrate |
| HEVC (H.265) | .mp4 |
Smaller files than H.264 at the same quality | Software encoding is slow; some players need the hvc1 tag to preview |
| ProRes | .mov |
Handing footage to an editor (Premiere/Resolve) | High quality, large files |
| VP9 | .mp4 |
Efficient web delivery | Slow to encode |
| AV1 | .mp4 |
The most efficient delivery codec | Slowest to encode |
| FFV1 | .mkv |
Archival / mastering | Visually lossless, very large |
| HAP / HAP Alpha / HAP Q | .mov |
Realtime / VJ playback (Resolume, etc.) | Cheap for the GPU to play back; HAP has no transparency, HAP Alpha/Q add alpha / more quality |
File sizes
- H.264, HEVC, VP9, AV1 are controlled by the Bitrate slider — higher bitrate means better quality and a bigger file. The hint next to the slider turns the current bitrate into a plain quality label for your resolution and FPS. As a rule of thumb, around 0.1 bits per pixel per second is a good quality for sharing.
- ProRes ignores the bitrate (it has its own) — expect files roughly 10× an H.264 of the same shot.
- FFV1 is lossless, so files can be several GB per minute at HD.
- HAP has a predictable size — about half a byte per pixel per frame (twice that for HAP Alpha / HAP Q). The window shows an exact estimate.
Tip: Hardware encoding (NVENC / Quick Sync / AMF) is the fast path and matters most for realtime Continuous capture. NVENC needs an NVIDIA driver version 570 or newer.
Continuous Capture (open-ended recording)
When you don't know the length up front — a live set, a performance, an audio-reactive jam — set Range to Continuous. Pressing Render then starts recording immediately and keeps going until you press the capture control again, which finalizes the file. There is no fixed end time.
Two clock models are available under Source:
- Realtime grabs the live output as you perform, paced to the target FPS, and leaves playback under your control. This is the mode for live/VJ use. It captures video only for now (no audio), at the native output resolution. A fast hardware encoder is recommended — with a software codec the capture may drop or duplicate frames to keep pace, and the render window warns you.
- Deterministic advances time at the target FPS until you stop, exactly like a normal render but without a predetermined end. It is frame-perfect even when encoding is slower than realtime, and records audio.
While a continuous capture runs, the progress bar is replaced by a sweeping activity indicator showing the captured frame count and elapsed time. Press Stop (or the capture shortcut) to finalize.
High-resolution rendering
Rendering is cheap compared to encoding, so you can trade a little time for a lot of quality. Set Resolution Scale above 1 to render larger than the output window — for example 2 turns a 1080p project into 4K. Thanks to TiXL's smart resolution setup the requested resolution flows through the whole project, so gradients, text, and antialiasing all sharpen up. This is the way to produce 4K masters or high-resolution stills from an HD comp.
Rendering with Motion Blur
[RenderWithMotionBlur] renders several slightly offset passes per frame and blends them, producing very high-quality motion blur. Because that is too expensive to do live, you keep its sample count low (or 0) while working and override it only for the export with the Motion Blur field in the Render To File window — so your interactive session stays smooth while the export gets the full quality.
A Motion Blur of -1 means "don't override" (the default). Values above 0 require a [RenderWithMotionBlur] operator somewhere above your output.
Saving Screenshots
The screenshot (camera) icon in the output window's toolbar saves the current frame as a PNG into your project's Screenshots/ folder.
Ctrl-click the icon to start continuous screenshot mode: TiXL then saves a screenshot on a fixed interval and the icon pulses in the attention colour, brightest right after each capture. Click the icon again to stop. Continuous capture pauses while a video or image-sequence export is running and resumes once it finishes.
Right-click the icon for options: start/stop continuous capture, pick the interval (1 s … 10 min), and choose the file format. PNG is lossless; JPG produces much smaller files, which is handy when capturing long continuous sequences. The interval can also be set under Settings → Interface → Output.
Technical Background
TiXL renders into a GPU texture (by default R16G16B16A16_Float — 16 bits per channel, high precision in the 0…1 range). Getting that onto disk as a video is more involved than it looks:
- Many file formats store pixels as Blue, Green, Red, Alpha — the bytes have to be reordered.
- Reading a texture back from the graphics card takes up to a few frames.
- Converting between pixel formats (16-bit float to 8-bit, etc.) is comparatively slow.
- Effects are often audio-reactive, but a deterministic export is not realtime — TiXL drives the timeline frame by frame so the result is exactly repeatable.
- Some operators are asynchronous (loading an image from the web, seeking a video). During a deterministic export TiXL waits for each to finish before writing the frame, trading speed for correctness.
These are the reasons a Continuous → Realtime capture (which grabs the live output instead) trades that determinism for keeping pace with a live performance.
Roadmap
Current exports are 8-bit. HDR output (e.g. EXR image sequences) and variable-frame-rate continuous capture are on the roadmap.