Codecs
Alchemist targets three video codecs: AV1, HEVC, and H.264. They are not interchangeable. Pick based on storage, playback compatibility, and available hardware.
Comparison
| Codec | File size | Quality efficiency | Compatibility | Encoding speed |
|---|---|---|---|---|
| AV1 | Smallest | Best | Growing | Slowest |
| HEVC | Smaller | Very high | Good on modern devices | Medium |
| H.264 | Largest | Lowest of the three | Universal | Fastest |
When to choose AV1
Use AV1 when saving the most space matters and your playback devices are modern enough to handle it.
Hardware support:
- NVIDIA: RTX 40 (Ada) NVENC — RTX 30 (Ampere) decodes AV1 but cannot encode it
- Intel: Arc, or integrated from Meteor Lake / Core Ultra onward (earlier iGPUs have no AV1 encoder)
- AMD: RDNA 3+ depending on driver/FFmpeg stack; HEVC/H.264 are the validated AMD paths, while AV1 remains driver/FFmpeg-stack sensitive (RDNA 2 is AV1 decode-only)
- Apple: no AV1 hardware encoder on any Mac — AV1 output uses the CPU (SVT-AV1); Apple Silicon can decode AV1 (M3+)
- CPU: always available through SVT-AV1
When to choose HEVC
Use HEVC when you want most of AV1’s storage benefit with better playback compatibility across TVs, phones, and set-top boxes.
Hardware support:
- NVIDIA: Maxwell+
- Intel: 6th gen+
- AMD: Polaris+
- Apple: M1+/T2 and newer
- CPU: x265
When to choose H.264
Use H.264 when compatibility is the priority and storage efficiency is secondary.
Hardware support:
- NVIDIA: broadly available
- Intel: broadly available
- AMD: broadly available
- Apple: broadly available
- CPU: x264
Hardware summary by vendor
| Vendor | AV1 | HEVC | H.264 |
|---|---|---|---|
| NVIDIA | RTX 40 (Ada) | Maxwell+ | Yes |
| Intel | Arc / Meteor Lake+ | 6th gen+ | Yes |
| AMD | RDNA 3+ on compatible driver/FFmpeg stacks | Polaris+ | Yes |
| Apple | CPU only (no HW encoder) | M1+/T2 | Yes |
| CPU | Yes | Yes | Yes |
BPP
BPP means bits per pixel. It measures how much video data is being spent per rendered pixel and frame, which makes it more useful than plain bitrate when you compare files across different resolutions and frame rates.
Typical ranges:
> 0.15: high quality, usually still worth evaluating~0.10: medium quality, often already efficient< 0.05: heavily compressed, likely to look blocky
Alchemist uses BPP because bitrate alone lies. A 4K file and a 1080p file can share the same bitrate and look completely different. BPP normalizes for resolution and frame rate, so the planner can skip files that are already efficiently compressed instead of re-encoding on guesswork.