# rav1e
Canonical URL: https://encode.wiki/tools/software-encoders/rav1e/
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License: CC BY-SA 4.0
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> **Repository:** [xiph/rav1e](https://github.com/xiph/rav1e). The fastest and safest AV1 encoder. Latest release: [v0.8.1](https://github.com/xiph/rav1e/releases/tag/v0.8.1), Jun 16, 2025. Last commit: Aug 31, 2026. License: BSD-2-Clause. Stars: 4,160.
[rav1e](https://github.com/xiph/rav1e) is an AV1 encoder written in Rust with hand-written assembly, developed by Xiph.org and Mozilla. It is BSD-2-Clause licensed. Its defaults are sensible, it is easy to build, and it is the AV1 encoder behind several Rust and AVIF tools: libavif can use it (`avifenc -c rav1e`), and the [cavif/ravif](https://github.com/kornelski/cavif-rs) AVIF encoder is built on it.
## Where rav1e stands
The latest stable release is **v0.8.1** (June 2025). The weekly pre-release builds stopped in September 2025. Since then the repository has seen mostly maintenance commits (toolchain bumps, lint fixes) rather than encoder work.
For video, most encoders now use [SVT-AV1](/tools/software-encoders/svt-av1/) (or one of its community forks) or [aomenc](/tools/software-encoders/aomenc/). rav1e is considerably slower than SVT-AV1, and the [mendevi encoder dataset](https://mendevi.readthedocs.io/1.3.5/dataset/explore/svtav1_vs_rav1e_vs_aom.html) found SVT-AV1 better at equal encoding time. rav1e has changed little since, while SVT-AV1 has kept improving. rav1e is still a reasonable choice if you need a pure-Rust library or already use it through libavif or GStreamer. For a new video workflow, start with SVT-AV1.
## Install
Prebuilt binaries are on the [releases page](https://github.com/xiph/rav1e/releases), and most distributions package `rav1e`. To build v0.8.1 you need a Rust toolchain and, on x86-64, NASM 2.14.02 or newer:
```sh
cargo install --locked rav1e
```
Or build the tagged release from source:
```sh
git clone --branch v0.8.1 https://github.com/xiph/rav1e.git
cd rav1e
cargo build --release
```
The binary is at `target/release/rav1e`. rav1e picks its SIMD code paths at runtime, so a normal build already uses your CPU's AVX2/AVX-512. `RUSTFLAGS="-C target-cpu=native"` produces a binary that only runs on CPUs like yours.
## Encode
rav1e reads Y4M and writes IVF. The input is a **positional** argument: `-i` is the minimum keyframe interval, not an input switch, so older commands like `rav1e -i input.y4m` do not work.
```sh
rav1e input.y4m -o output.ivf --quantizer 80 --speed 6
```
Pipe from FFmpeg to encode anything else. 10-bit output is more efficient and bands less, even from 8-bit sources:
```sh
ffmpeg -i input.mkv -pix_fmt yuv420p10le -strict -1 -f yuv4mpegpipe - | \
rav1e - -o output.ivf --quantizer 80 --speed 6 --photon-noise 8
```
FFmpeg still needs `-strict -1` to write Y4M above 8 bits. Mux the IVF into MKV or MP4 afterwards (for example `ffmpeg -i output.ivf -i input.mkv -map 0:v -map 1:a -c copy final.mkv`), or use [mkvmerge](/tools/utilities/mkvtoolnix/).
For 4K, add tiles. They help both encoding speed and decoding speed:
```sh
ffmpeg -i input.mkv -pix_fmt yuv420p10le -strict -1 -f yuv4mpegpipe - | \
rav1e - -o output.ivf --quantizer 72 --speed 6 --tile-cols 2 --photon-noise 8
```
### Two-pass target bitrate
```sh
rav1e input.y4m -o /dev/null --bitrate 3000 --first-pass stats.bin
rav1e input.y4m -o output.ivf --bitrate 3000 --second-pass stats.bin
```
`--bitrate` is in kbit/s. The first pass also writes a video file, so send it to `/dev/null` (otherwise the second pass stops to ask before overwriting). In bitrate mode `--quantizer` becomes the worst (maximum) quantizer allowed, and `--min-quantizer` the best. Each pass reads the input, so use a file or regenerate an identical pipe.
## Options that matter
| Option | Default | Notes |
| -------------------------------------------------- | -------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `--quantizer N` | 100 | Constant quantizer, 1–255 (0 aborts: lossless is not implemented). Lower is higher quality. This is the AV1 `base_q_idx` scale (see below). |
| `--speed N`, `-s` | 6 | 0 (slowest) to 10 (fastest). Faster speeds also shorten the RDO lookahead (40 frames at speeds 0–2, 30 at 3–5, 20 at 6–7, 10 at 8–10). |
| `--photon-noise N` | 0 (off) | AV1 film-grain synthesis, strength 0–64. The decoder adds the noise, so it costs almost no bitrate and can mask banding. It does not copy the source's grain. It also lowers full-reference metric scores, so turn it off when comparing encodes with metrics. |
| `--tile-cols N`, `--tile-rows N`, `--tiles N` | automatic | Tile **counts** (powers of two), not log2 values. `--tiles` sets a minimum total and cannot be combined with the other two. More tiles raise thread utilisation and decoder parallelism at a small efficiency cost. |
| `--threads N` | all logical CPUs | Thread pool size. A single rav1e encode does not use many cores well without more tiles. On many-core machines, running several chunked encodes (e.g. via [Av1an](/tools/utilities/av1an/)) scales better. |
| `--keyint N`, `-I` / `--min-keyint N`, `-i` | 240 / 12 | Maximum and minimum keyframe distance in frames. Scene-cut keyframes are on by default. |
| `--tune` | `Psychovisual` | `Psnr` optimises for the metric and looks worse. Leave the default. |
| `--bitrate N`, `--first-pass`, `--second-pass` | quantizer mode | Bitrate targeting, single or two-pass. |
| `--no-scene-detection` | off | For chunked encoders that place keyframes themselves. |
| `--primaries`, `--transfer`, `--matrix`, `--range` | unspecified, limited range | Colour signalling written into the stream. It labels the colour; it does not convert it. |
| `--mastering-display`, `--content-light` | unset | HDR10 static metadata. |
> **Tip — Converting from aomenc or SVT-AV1.**
>
> aomenc's `--cq-level` and SVT-AV1's `--crf` use a 0–63 scale that maps to AV1's 0–255 quantizer index at roughly ×4. rav1e's `--quantizer` is that index directly. A 0–63 value multiplied by 4 (`--crf 20` → `--quantizer 80`) therefore lands on a similar base quantizer. Each encoder distributes bits differently around that base, so file size and quality will not match exactly.
## HDR
For HDR10, signal the colour and static metadata from your source:
```sh
rav1e input.y4m -o output.ivf --quantizer 80 --speed 6 \
--primaries BT2020 --transfer SMPTE2084 --matrix BT2020NCL \
--mastering-display "G(0.17,0.797)B(0.131,0.046)R(0.708,0.292)WP(0.3127,0.329)L(1000,0.0001)" \
--content-light 1000,400
```
Replace the mastering-display and content-light values with your source's. `ffprobe -show_frames -read_intervals "%+#1"` prints them as fractions, which you need to convert to decimals and cd/m². HDR10+ dynamic metadata is not supported in a release: quietvoid's [pull request #3000](https://github.com/xiph/rav1e/pull/3000), which adds `--hdr10plus-json`, is still unmerged.
## FFmpeg (`librav1e`)
```sh
ffmpeg -i input.mkv -c:v librav1e -qp 80 -speed 6 -c:a libopus output.mkv
```
`-qp` maps to `--quantizer`, and `-tiles`/`-tile-rows`/`-tile-columns` map to the tile options. Other settings go through `-rav1e-params key=value:key=value`, which only accepts rav1e's C API keys: `speed`, `quantizer`, `min_quantizer`, `bitrate`, `key_frame_interval`, `min_key_frame_interval`, `switch_frame_interval`, `reservoir_frame_delay`, `rdo_lookahead_frames`, `low_latency`, `no_scene_detection`, `tune`, `tiles`, `tile_rows`, `tile_cols`, `threads`, `still_picture`, `level` and `enable_timing_info`.
> **Caution.**
>
> Photon noise is not one of those keys, so grain synthesis is only available through the rav1e CLI. FFmpeg prints a warning for an unknown `-rav1e-params` key but encodes anyway.
## FFmpeg librav1e private options (n9.0.2)
These are the private options of the `librav1e` encoder in FFmpeg 9.0.2. Generic FFmpeg options also reach rav1e: `-g` and `-keyint_min` set the keyframe interval, `-b:v` (bit/s) switches to bitrate mode with `-qmax` (default 255) and `-qmin` as quantizer limits, `-pass 1`/`-pass 2` run a two-pass encode (needs `-b:v`), `-threads` sets the thread pool, and the input's colour range, primaries, transfer and matrix are signalled automatically. `-rav1e-params` is applied first, so these and the private options below override the same setting given there.
Private AVOptions (6 options)
| Option | Default | Type and range | What it does |
| --------------- | ------- | -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `-qp` | -1 | int, -1–255 | Constant quantizer, same scale as `--quantizer`. -1 leaves rav1e's default of 100. Takes priority over `-b:v` if both are given. |
| `-speed` | -1 | int, -1–10 | Speed preset, as `--speed`. -1 leaves rav1e's default of 6. Setting it resets the speed-derived keys `rdo_lookahead_frames` and `no_scene_detection` given in `-rav1e-params`. |
| `-tiles` | 0 | int, ≥ -1 | Minimum total tile count, as `--tiles`; rav1e picks the rows and columns and ignores `-tile-rows`/`-tile-columns`. 0 or -1 leaves tiling to rav1e. |
| `-tile-rows` | 0 | int, ≥ -1 | Number of tile rows: a count (power of two), not log2. 0 or -1 leaves it automatic. |
| `-tile-columns` | 0 | int, ≥ -1 | Number of tile columns, same rules as `-tile-rows`. The FFmpeg name is `-tile-columns`, not `-tile-cols`. |
| `-rav1e-params` | unset | dictionary | `key=value` pairs separated by `:`, using rav1e's C API keys (listed above), not CLI flag names. Booleans must be `true` or `false`, and `bitrate` is in bit/s. Put `speed` first: it resets lookahead and scene-detection keys. Bad keys only warn. |
## Complete native parameter reference
Every option of the `rav1e` 0.8.1 command-line encoder. Options of the `advanced` subcommand go after the main options and the `advanced` keyword (`rav1e in.y4m -o out.ivf advanced --save-config enc.toml`). Named values such as `Psnr`, `Full` or `BT2020` are case-insensitive.
Input and output (7 options)
| Option | Default | What it does |
| ----------------- | -------------- | --------------------------------------------------------------------------------------------------------------------------------------- |
| `INPUT` | required | Y4M input file, or `-` for stdin. It is positional: `-i` is `--min-keyint`, not an input flag. |
| `--output`, `-o` | required | IVF output file, or `-` for stdout. A file name must end in `.ivf` or have no extension. |
| `-y` | off | Overwrite an existing output file. Without it rav1e asks for confirmation on stdin, so an encode with piped input exits instead. |
| `--limit`, `-l` | 0 (all frames) | Stop after this many frames. `--still-picture` allows at most 1. |
| `--skip` | 0 | Read and discard this many frames from the start of the input before encoding. |
| `--help`, `-h` | — | Print help; `-h` gives the short form. |
| `--version`, `-V` | — | Print the version. `--version` also shows the compiler, assembly level and whether threading and unstable features were built in. |
Rate control and speed (9 options)
| Option | Default | What it does |
| ------------------------- | ------------------------------------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `--quantizer` | 100 (255 with `--bitrate`) | Quantizer index 1–255; lower is higher quality. 0 (lossless) is not implemented and aborts. With `--bitrate` it is the highest quantizer rate control may use. |
| `--min-quantizer` | 0 | Lowest quantizer (best quality) rate control may use in bitrate mode, 0–255. |
| `--bitrate`, `-b` | unset (quantizer mode) | Target bitrate in kbit/s. Switches from constant quantizer to rate control. |
| `--first-pass` | unset | Run the first pass of a two-pass encode and write its statistics to this file. Needs `--bitrate`. |
| `--second-pass` | unset | Run the second pass using statistics from `--first-pass`. Needs `--bitrate` and the same input. |
| `--reservoir-frame-delay` | min(240, 1.5 × keyint), at least 12 | Window, in frames, over which rate control spreads its bit reservoir; minimum 12. A longer window lets the bitrate vary more between scenes. |
| `--speed`, `-s` | 6 | Preset 0–10; 0 is slowest and best. Slower presets search more partition sizes, transform types and motion vectors. Upstream does not recommend 0 or 10. |
| `--rdo-lookahead-frames` | 20 at speed 6 | Frames analysed ahead for rate–distortion decisions. The preset sets 40 at speeds 0–2, 30 at 3–5, 20 at 6–7 and 10 at 8–10. |
| `--tune` | Psychovisual | `Psychovisual` or `Psnr`. `Psnr` optimises for the metric and looks worse. |
Keyframes and frame structure (7 options)
| Option | Default | What it does |
| ------------------------------- | ------------------ | -------------------------------------------------------------------------------------------------------------------------------------------------- |
| `--keyint`, `-I` | 240 | Maximum frames between keyframes. 0 removes the limit, leaving only scene-cut keyframes. |
| `--min-keyint`, `-i` | 12 | Minimum frames between scene-cut keyframes; capped at `--keyint`. |
| `--no-scene-detection` | off | Turn off scene-cut keyframes. Use it when a chunking tool such as Av1an already splits at scene cuts; on a full encode it costs quality. |
| `--scd-speed` | 0 (1 at speed 10) | Scene-detection mode: 0 standard, 1 fast. |
| `--switch-frame-interval`, `-S` | 0 (off) | Insert an AV1 switch frame at most every N frames. A player can change to another stream of the same content at a switch frame. |
| `--low-latency` | off | Disable frame reordering so no frame waits for later ones, for real-time use. Compresses much less efficiently. |
| `--still-picture` | off | Encode only the first frame, with the AV1 still-picture sequence header. The output is still IVF; use an AVIF encoder such as avifenc or cavif for images. |
Film grain (2 options)
| Option | Default | What it does |
| -------------------------------------------- | ------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `--photon-noise` | 0 (off) | Add synthetic luma grain at strength 0–64 (strength × 100 is the simulated ISO, so 8 ≈ ISO 800). The decoder renders it through AV1 film-grain synthesis; it does not model the source's grain. Cannot combine with a grain table. |
| `--film-grain-table`, `--photon-noise-table` | unset | Apply grain from a film-grain table file, in the text format aomenc and SVT-AV1 also read. `--photon-noise-table` is a hidden alias. |
Threading and tiles (5 options)
| Option | Default | What it does |
| ------------- | ------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `--threads` | 0 (logical CPUs) | Maximum worker threads. One encode needs several tiles to keep many threads busy. |
| `--tile-cols` | 0 (automatic) | Number of tile columns: a count (power of two, up to 64), not log2. 0 uses the fewest the frame size allows, and rav1e adjusts other values to fit the frame. |
| `--tile-rows` | 0 (automatic) | Number of tile rows, same rules as `--tile-cols`. |
| `--tiles` | unset | Minimum total tile count; rav1e picks the rows and columns. Cannot be combined with `--tile-rows` or `--tile-cols`. |
| `--slots` | 0 (off) | Encode up to N GOPs in parallel; values above 1 enable it. Requires a build with the `unstable` feature, and only the `rav1e-ch` binary (also needing `channel-api`) uses it. |
Colour and HDR metadata (6 options)
These options only label the stream. They do not convert pixels.
| Option | Default | What it does |
| --------------------- | ----------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `--range` | Limited | `Limited` or `Full`. rav1e does not read the range from the Y4M header, so set `Full` yourself for full-range input. |
| `--primaries` | Unspecified | `BT709`, `BT470M`, `BT470BG`, `BT601`, `SMPTE240`, `GenericFilm`, `BT2020`, `XYZ`, `SMPTE431`, `SMPTE432`, `EBU3213` or `Unspecified`. |
| `--transfer` | Unspecified | `BT709`, `BT470M`, `BT470BG`, `BT601`, `SMPTE240`, `Linear`, `Log100`, `Log100Sqrt10`, `IEC61966`, `BT1361`, `SRGB`, `BT2020_10Bit`, `BT2020_12Bit`, `SMPTE2084` (PQ), `SMPTE428`, `HLG` or `Unspecified`. |
| `--matrix` | Unspecified | `Identity`, `BT709`, `FCC`, `BT470BG`, `BT601`, `SMPTE240`, `YCgCo`, `BT2020NCL`, `BT2020CL`, `SMPTE2085`, `ChromatNCL`, `ChromatCL`, `ICtCp` or `Unspecified`. |
| `--mastering-display` | unset | HDR mastering display as `G(x,y)B(x,y)R(x,y)WP(x,y)L(max,min)`: CIE xy chromaticities as decimals 0–1, luminance in cd/m². |
| `--content-light` | unset | MaxCLL and MaxFALL in cd/m², as `max_cll,max_fall` (for example `1000,400`). `0,0` writes nothing. |
Frame rate and level (3 options)
| Option | Default | What it does |
| -------------- | --------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `--frame-rate` | from Y4M header | Override the output frame rate's numerator; needs `--time-scale` (`--frame-rate 24000 --time-scale 1001` is 23.976 fps). Changes timestamps only. |
| `--time-scale` | 0 (unset) | Frame-rate denominator for `--frame-rate`; use 1 for whole-number rates. Ignored without `--frame-rate`. |
| `--level` | auto | AV1 level to signal and enforce: 2.0, 2.1, 3.0, 3.1, 4.0, 4.1, 5.0–5.3 or 6.0–6.3. `auto` and `unconstrained` both write level 31 (no level). The encode fails if the frame size exceeds the level. |
Statistics and debugging (7 options)
| Option | Default | What it does |
| ------------------------ | ------- | ---------------------------------------------------------------------------------------------------------------- |
| `--verbose`, `-v` | off | Print statistics for every frame. Cannot combine with `--quiet`. |
| `--quiet`, `-q` | off | Print no progress or summary. |
| `--benchmark` | off | Print a timing summary at the end. |
| `--psnr` | off | Report PSNR of the reconstruction against the input. Cannot combine with `--metrics`. |
| `--metrics` | off | Report PSNR, PSNR-HVS, SSIM, MS-SSIM and CIEDE2000 against the input. Slows the encode. |
| `--reconstruction`, `-r` | unset | Also write the encoder's reconstructed frames (what a decoder outputs) to this Y4M file. |
| `--high-bitdepth` | off | Use the high-bit-depth code path for 8-bit input too. For debugging. |
Advanced subcommand (4 options)
| Option | Default | What it does |
| --------------------------------------- | ------- | ---------------------------------------------------------------------------------------------------------------------------------------------------- |
| `advanced --completion`, `advanced -c` | unset | Print a shell completion script for `bash`, `elvish`, `fish`, `powershell` or `zsh`; `zsh` panics in 0.8.1. An input and `-o` are still required (`rav1e - -o - advanced -c bash`). |
| `advanced --save-config`, `advanced -s` | unset | Write the encoder configuration to a TOML file. Requires a build with the `serialize` feature, which default builds lack. |
| `advanced --load-config`, `advanced -l` | unset | Load the encoder configuration from a TOML file made by `--save-config`; encoder options on the command line are then ignored. Requires `serialize`. |
| `advanced --help`, `advanced -h` | — | Print help for the subcommand. |