AV1
AV1 is the next-generation royalty-free video codec developed by the Alliance for Open Media (Google, Apple, Netflix, Amazon, and others). It delivers roughly 50% better compression than H.264 and is the most efficient codec Transcodely supports. Transcodely uses the SVT-AV1 encoder, which offers the best balance of speed and quality among AV1 implementations.
Quick Start
{
"type": "mp4",
"video": [
{
"codec": "av1",
"resolution": "1080p",
"quality": "standard"
}
]
}AV1Options Reference
Override defaults by passing the av1 object on a video variant:
{
"codec": "av1",
"resolution": "1080p",
"quality": "standard",
"av1": {
"preset": 6,
"crf": 35,
"film_grain": 8,
"tile_columns": 2
}
}Key Differences from H.264/H.265
AV1 uses numeric values for preset and tune, not strings:
| Concept | H.264/H.265 | AV1 |
|---|---|---|
| Speed control | preset (string) | preset (integer: 3-12) |
| Optimization target | tune (string) | tune (integer: 0 or 1) |
| CRF range | 15-35 / 18-35 | 20-55 |
| Max bitrate | 240,000 kbps | 100,000 kbps |
| Film grain | Via tune: "grain" | Dedicated film_grain parameter (0-50) |
| Loop filters | Not configurable | enable_dlf, enable_cdef, enable_restoration |
Presets
AV1 presets are numeric. Lower values produce better quality at slower speeds.
| Preset | Speed | Quality | Allowed |
|---|---|---|---|
| 0-2 | Extremely slow | Best | Not allowed (impractical for production) |
| 3 | Very slow | Excellent | Yes |
| 4 | Slow | Very good | Yes (default for premium tier) |
| 5 | Below average | Good | Yes |
| 6 | Average | Good | Yes (default for standard tier) |
| 7 | Above average | Above average | Yes |
| 8 | Fast | Average | Yes |
| 9 | Faster | Below average | Yes |
| 10 | Very fast | Lower | Yes (default for economy tier) |
| 11 | Fastest practical | Low | Yes |
| 12 | Maximum speed | Lowest | Yes |
| 13 | Extreme speed | Very low | Not allowed (quality too low) |
Default by quality tier:
| Quality Tier | Default Preset | Default CRF |
|---|---|---|
economy | 10 | 45 |
standard | 6 | 35 |
premium | 4 | 28 |
Tune
AV1 uses numeric tune values:
| Value | Mode | Description |
|---|---|---|
| 0 | VQ (Visual Quality) | Optimizes for perceptual quality (default, recommended) |
| 1 | PSNR | Optimizes for objective metrics (benchmarking, research) |
For production content, always use 0 (VQ). The PSNR mode is useful for quality benchmarking but does not produce the best perceptual results.
CRF (Constant Rate Factor)
Allowed range: 20-55. AV1’s CRF scale is different from H.264 — higher values are needed for similar visual quality.
| CRF Range | Quality | Use Case |
|---|---|---|
| 20-25 | Near-lossless | Archival, mastering |
| 26-30 | High quality | Premium streaming |
| 31-38 | Good quality | Standard streaming (default: 35) |
| 39-45 | Acceptable | Mobile, previews, economy |
| 46-55 | Lower quality | Thumbnails, low-bandwidth |
Approximate CRF equivalents:
| AV1 CRF | H.264 CRF | Visual Quality |
|---|---|---|
| 28 | 18 | Near-lossless |
| 35 | 23 | High quality streaming |
| 45 | 28 | Good for mobile |
Film Grain Synthesis
AV1 has a built-in film grain synthesis feature that can significantly reduce file size for grainy content. Instead of encoding the grain (which wastes bits), the encoder analyzes the grain pattern, removes it during encoding, and stores parameters that allow the decoder to re-synthesize it during playback.
| Parameter | Range | Default | Description |
|---|---|---|---|
film_grain | 0-50 | 0 (disabled) | Grain synthesis strength |
Recommended values:
| Value | Use Case |
|---|---|
| 0 | Clean, digitally-produced content |
| 5-10 | Light grain, general footage |
| 15-25 | Moderate grain, film-sourced content |
| 30-50 | Heavy grain, vintage/noir content |
{
"codec": "av1",
"resolution": "1080p",
"quality": "premium",
"av1": {
"crf": 30,
"film_grain": 15
}
}Tile Configuration
Like VP9, AV1 supports frame tiling for parallel encoding:
| Parameter | Range | Default | Description |
|---|---|---|---|
tile_columns | 0-4 | Auto | Tile columns (log2 scale: 2 = 4 columns) |
tile_rows | 0-4 | Auto | Tile rows (log2 scale: 2 = 4 rows) |
Auto-detection selects tile count based on resolution. Override only when you need to tune parallelism.
Loop Filters
AV1 includes three post-processing filters that reduce encoding artifacts. All are enabled by default:
| Filter | Parameter | Default | Description |
|---|---|---|---|
| Deblocking (DLF) | enable_dlf | true | Reduces blocking artifacts at tile/block boundaries |
| CDEF | enable_cdef | true | Directional enhancement filter for edge preservation |
| Loop Restoration | enable_restoration | true | Final-pass filter for perceptual quality improvement |
Disabling filters speeds up encoding and decoding at a quality cost. Only disable if you have specific performance constraints:
{
"codec": "av1",
"resolution": "720p",
"quality": "economy",
"av1": {
"preset": 10,
"enable_cdef": false,
"enable_restoration": false
}
}Other Parameters
| Parameter | Range | Default | Description |
|---|---|---|---|
bitrate | 100-100,000 kbps | None (CRF mode) | Target bitrate |
max_bitrate | 100-100,000 kbps | None | Maximum bitrate |
keyint | 1-600 frames | 250 | Maximum keyframe interval |
Example: Maximum Compression
{
"codec": "av1",
"resolution": "1080p",
"quality": "premium",
"av1": {
"preset": 4,
"crf": 28,
"film_grain": 10,
"tile_columns": 2
}
}Example: Fast Web Preview
{
"codec": "av1",
"resolution": "480p",
"quality": "economy",
"av1": {
"preset": 10,
"crf": 45,
"enable_restoration": false
}
}Container Compatibility
AV1 works with: MP4, WebM, MKV, HLS (fMP4 segments), DASH
AV1 does not work with: MOV, TS