README
¶
gav1d
AV1 video and AVIF image decoder and encoder in pure Go.
A port of dav1d, bit-exact against it. No CGo, no dependencies.
SIMD support for amd64 (AVX2, AVX-512), arm64 (NEON) and riscv64 (RVV, with GORISCV64=rva23u64).
Build with -tags noasm for pure Go everywhere.
Decoding
img, err := avif.Decode(r)
avif.Decode returns *image.NRGBA, or *image.NRGBA64 above 8 bits, and registers itself with
image.RegisterFormat. The av1 package decodes the bitstream on its own, a temporal unit at a time:
d := av1.Decoder{}
for _, tu := range temporalUnits {
pics, err := d.DecodeOBUs(tu)
...
}
Encoding
err := avif.Encode(w, img, avif.EncodeOptions{Quality: 70, Speed: 6})
The encoder is all-intra and 8-bit, at 4:2:0 or grayscale, with alpha carried as a second
item. Speed trades search effort for encoding time.
Supported
8/10/12-bit, 4:2:0/4:2:2/4:4:4/monochrome, film grain, scalable streams, and in the container alpha, grid,
clap/irot/imir, colr, image sequences, Exif and XMP, and gain maps.
License
The decoder is a port of dav1d; the encoder's forward transform is a port of libaom. Both are BSD-2-Clause, and both notices are in COPYING.
This project is an implementation of a codec. It gives you no special rights on the AV1 patents. Please read the AV1 patent license that applies to the AV1 specification and codec.
Directories