# FFmpeg Filtergraph Builder Turn plain filter steps like 'scale to 720p, crop to square, fade in 1s' into a validated ffmpeg -filter_complex string, -vf chain, or full command. Nothing runs. ## Run it - **CLI:** `gizza tool ffmpeg-filtergraph-builder "scale to 720p crop to square fade in 1s"` - **Web:** https://gizza.ai/tools/ffmpeg-filtergraph-builder/ - **Agents:** machine-readable descriptor (parameters JSON Schema) at https://gizza.ai/tools/ffmpeg-filtergraph-builder/tool.json ## Inputs - `steps` — Filter steps, one per line _(field)_ - `stream` — Stream _(field)_ - `output` — Output form _(field)_ - `input_label` — Source pad label _(field)_ - `output_label` — Sink pad label _(field)_ - `input_file` — Input file (command form) _(field)_ - `output_file` — Output file (command form) _(field)_ - `explain` — Explain each step _(field)_ ## Output - Filtergraph (text) ## Query parameters Open the tool pre-filled and auto-run via URL: - `steps` — Filter steps, one per line - `stream` — Stream - `output` — Output form - `input_label` — Source pad label - `output_label` — Sink pad label - `input_file` — Input file (command form) - `output_file` — Output file (command form) - `explain` — Explain each step Example: `https://gizza.ai/tools/ffmpeg-filtergraph-builder/?steps=scale%20to%20720p%0Acrop%20to%20square%0Afade%20in%201s&stream=video&output=filter_complex&input_label=auto%20%280%3Av%20for%20video%2C%200%3Aa%20for%20audio%29&output_label=out&input_file=input.mp4&output_file=output.mp4&explain=true` --- ## About this tool **FFmpeg Filtergraph Builder** turns an ordered list of plain filter steps into a **validated ffmpeg filtergraph string**. You write what you want to happen, in order; it writes the syntax — commas between filters, colons between options, quoting for expressions that contain commas, and the `[in]…[out]` pad labels. **Nothing is executed.** No file is uploaded, no ffmpeg process is started, and no step you type is ever run — the tool only *composes and checks* the text you'd paste into your own terminal. Everything happens locally in your browser via WebAssembly. ### Worked example Steps: ``` scale to 720p crop to square fade in 1s ``` Output (`-filter_complex` form): ``` [0:v]scale=-2:720,crop='min(iw,ih)':'min(iw,ih)',fade=t=in:st=0:d=1[out] ``` Switch **Output form** to *Full ffmpeg command line* and the same steps become: ``` ffmpeg -i input.mp4 -filter_complex "[0:v]scale=-2:720,crop='min(iw,ih)':'min(iw,ih)',fade=t=in:st=0:d=1[out]" -map "[out]" -map "0:a?" output.mp4 ``` `-map "0:a?"` keeps the original audio if the file has any, and is skipped silently if it doesn't. ### Steps you can write Steps go one per line. You can also separate them with `;` or the word `then`, and list markers (`-`, `1.`) are ignored, so a pasted recipe usually works as-is. Filler words (`to`, `the`, `by`, `with`) are ignored too — `scale to 720p` and `scale 720p` are the same step. **Video steps** | Step | Examples | Compiles to | | --- | --- | --- | | `scale` | `scale 1280x720`, `scale 720p`, `scale width 1280`, `scale 50%` | `scale=…` | | `crop` | `crop square`, `crop 640x640`, `crop 16:9`, `crop 80%` | `crop=…` (centred) | | `pad` | `pad 1920x1080`, `pad 16:9 #101010` | `pad=…` (centred, black by default) | | `fade` | `fade in`, `fade in 2s`, `fade out 3 at 57` | `fade=t=…:st=…:d=…` | | `rotate` | `rotate 90`, `rotate 180 degrees`, `rotate 270` | `transpose=…` | | `flip` | `flip horizontal`, `flip vertical` | `hflip` / `vflip` | | `grayscale` | `grayscale`, `black and white` | `hue=s=0` | | `blur` / `sharpen` | `blur`, `blur 12`, `sharpen 1.5` | `gblur=sigma=…` / `unsharp=…` | | `fps` | `fps 30` | `fps=30` | | `speed` | `speed 2x`, `speed 0.5` | `setpts=…*PTS` | | `trim` | `trim 5 to 20` | `trim=…,setpts=PTS-STARTPTS` | | `reverse` | `reverse` | `reverse` | | `brightness` / `contrast` / `saturation` / `hue` | `brightness 0.1`, `saturation 1.4`, `hue 90` | `eq=…` / `hue=h=…` | | `text` | `text "Hello" size 36 color yellow position top box` | `drawtext=…` | | `raw` | `raw vibrance=intensity=0.5` | passed through, syntax-checked | **Audio steps** (set *Stream* to **Audio**) `volume 2` / `volume -6dB`, `fade in 2` / `fade out 3 at 57`, `trim 0 to 30`, `speed 1.25` (chained `atempo` when the factor is outside 0.5–2), `normalize` (`loudnorm=I=-16:TP=-1.5:LRA=11`), `mono`, `highpass 120`, `lowpass 8000`, `reverse`, and `raw`. ### Limits and edge cases - **One linear chain.** The builder emits a single chain, so multi-input filters (`overlay`, `concat`, `amix`) are out of scope — a `;` in a `raw` step is rejected for that reason. Use `raw` for a single exotic filter instead. - **Max 30 steps**, and at most 8,000 characters of step text. - **Aspect vs. pixels:** a colon means an aspect ratio (`crop 16:9`), an `x` means pixels (`crop 640x640`). - **Caption text** may not contain single quotes, backslashes, or control characters — those can't be escaped safely inside a filtergraph — and is emitted with `expansion=none` so a `%{…}` sequence stays literal text. - **File names** in the command form are limited to letters, digits and `. _ - + /`, so nothing that could change the meaning of a shell command can be pasted in. Rename the file or edit the command by hand for anything else. - The generated graph is checked for balanced quotes and brackets before it is returned, but ffmpeg still has the last word — filter availability depends on how your ffmpeg build was compiled (`drawtext` needs `--enable-libfreetype`). ## FAQ
Does this run ffmpeg or touch my video? No. It's a text tool: steps in, filtergraph string out. No file is read or uploaded, and no ffmpeg process is ever started — not in the browser, not in the CLI. You copy the result into your own terminal, where you stay in control of what runs. If you want a file actually transformed, use one of the dedicated video or audio tools instead.
What's the difference between the three output forms? `-filter_complex` wraps the chain in pad labels — `[0:v]…[out]` — which is what you need when you map the result explicitly or work with several streams. The `-vf` / `-af` form is the same chain with no labels, which is the shorter way to filter one stream. The command form embeds the labelled graph in a complete `ffmpeg -i … -map …` line you can paste straight into a shell.
Why is `crop to square` written with quotes and `min()`? Cropping to a square means "use the shorter side", which is the expression `min(iw,ih)` — and that expression contains a comma, which ffmpeg would otherwise read as the separator between two filters. Wrapping it in single quotes keeps the comma inside the argument, so `crop='min(iw,ih)':'min(iw,ih)'` is one filter. Crop centres itself when you don't give `x`/`y`, so no offset is needed.
Can I use a filter the builder doesn't know? Yes — write `raw` followed by the filter exactly as ffmpeg expects it, for example `raw vibrance=intensity=0.5`. It's checked for a valid filter name, balanced quotes and brackets, and that it's a single filter, then placed in the chain in order. Filter *names* aren't checked against your ffmpeg build, since this tool never talks to ffmpeg.
Why does an audio speed change produce several atempo filters? Each `atempo` instance is defined for factors between 0.5 and 2. A bigger change is expressed as a chain whose factors multiply back to what you asked for, so `speed 4x` becomes `atempo=2,atempo=2` and `speed 3` becomes `atempo=2,atempo=1.5`. That's the standard way to keep the result in range.
What happens when a step is wrong? You get an error naming the step number, the text you wrote, what was expected, and what was received — for example *step 2 ('sparkle 3'): unknown video step 'sparkle'*, followed by the list of steps that are supported. Nothing partial is returned, so you never copy a half-built graph.
## Related tools - [Change Video Speed](https://gizza.ai/tools/change-speed/): Speed up or slow down a video right in your browser, keeping audio in sync — pick a speed factor (0.25x–4x). Re-encodes locally with ffmpeg, nothing is uploaded, free. - [Extract Video Frames to a Contact Sheet](https://gizza.ai/tools/extract-frames/): Sample frames from a video by interval, fps or scene change and tile them into one contact-sheet image. Free, in your browser with ffmpeg, nothing is uploaded. - [Gamma Correct an Image](https://gizza.ai/tools/gamma-correct/): Apply gamma correction to image midtones in your browser, with per-channel gamma, highlight protection and PNG/JPG/WebP output options. - [GIF to MP4 / WebM](https://gizza.ai/tools/gif-to-mp4/): Convert an animated GIF into a much smaller MP4 or WebM video, right in your browser. Re-encodes locally with ffmpeg (H.264 / VP9), nothing is uploaded, free. - [Loop a Video](https://gizza.ai/tools/loop-video/): Loop a video or GIF into one continuous file — repeat it N times or fill a target duration, free and in your browser with nothing uploaded.