less-avc - Less Advanced Video Coding - H.264 Encoder

This module contains a pure Rust implementation of an H.264 encoder optimized for lossless encoding. It is simple ("less advanced") and uses a small subset of the encoder features in the H.264 specification.

Features and characteristics:

Pure rust.
No use of unsafe.
Lossless encoding of 8 bit and 12 bit monochrome (luminance only 4:0:0) and color (4:2:0) data.
Includes an optimized path for luminance-only data in which no chroma data is saved.
Encodes using ALL-Intra, also called All-I. Every frame is recorded as an I (intra) frame (also "keyframe") using PCM encoding.
Tests decode image with openh264 and ffmpeg to ensure encoded image is losslessly preserved.
Can be compiled without using the rust standard library std. In other words, the no_std attribute is specified. (A global allocator is required.)

Desired but not implemented feature:

Support for other bit-depths and chroma sampling resolutions (e.g. 4:4:4).

Worthy of consideration features:

Support for context-adaptive variable-length coding (CAVLC).
Support for context-adaptive binary arithmetic coding (CABAC).

This was inspired by Ben Mesander's World's Smallest H.264 Encoder.

Testing

Run the basic tests with:

cargo test

Full round-trip tests with ffmpeg and openh264 are in the testbench directory and crate. For those:

cd testbench
cargo test

These tests can export the created streams to .h264 files if the LESSAVC_SAVE_TEST_H264 environment variable is set. (To view the location where the .h264 files are saved, run the tests with cargo test -- --nocapture.) To convert these to .mp4:

#!/bin/bash -x
set -o errexit

FILES="./*.h264"
for f in $FILES
do
    echo "Processing $f file..."
    ffmpeg -i $f -vcodec copy $f.mp4
    # ffmpeg -i $f $f.png
done

Benchmarking

Benchmarks are in the testbench directory and crate:

cd testbench
cargo bench

# Or, to benckmark while compiling for the native CPU architecture, like so:
RUSTFLAGS='-C target-cpu=native' cargo bench

License

Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.

strawlab/less-avc

less-avc - Less Advanced Video Coding - H.264 Encoder

Testing

Benchmarking

License