https://github.com/stan-smith/aml-gst-rs

GStreamer HW encoder/decoder plugin for Amlogic A311D2 (VIM4)
https://github.com/stan-smith/aml-gst-rs

Last synced: 3 months ago
JSON representation

GStreamer HW encoder/decoder plugin for Amlogic A311D2 (VIM4)

• Host: GitHub
• URL: https://github.com/stan-smith/aml-gst-rs
• Owner: stan-smith
• Created: 2026-02-27T16:22:14.000Z (5 months ago)
• Default Branch: master
• Last Pushed: 2026-03-02T16:44:12.000Z (5 months ago)
• Last Synced: 2026-03-30T16:42:06.465Z (4 months ago)
• Language: Rust
• Size: 15.6 KB
• Stars: 0
• Watchers: 0
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

Awesome Lists containing this project

README

          
aml-gst-rs

GStreamer plugin providing hardware-accelerated video encoding and decoding

for Amlogic A311D2 SoCs (Khadas VIM4). Wraps the amvenc_* API from

libamvenc.so and the V4L2 stateful decoder.

Elements:

  amlvenc_rs - H265/H264 hardware encoder

    codec     h265 (default) or h264

    bitrate   100000-50000000 (default 2000000), changeable during playback

    gop       1-1000 (default 30)

  amlvdec_rs - H264 hardware decoder

    framerate 1-240 (default 25)

    Wraps v4l2h264dec and fixes two kernel driver bugs:

    - framerate=0/1 in output caps

    - NV12 height alignment (1080 -> 1088) causing wrong UV plane offset

Build (natively on the target):

  cargo build --release

  sudo cp target/release/libgstamlvenc.so \

    /usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstamlvenc_rs.so

  rm -f ~/.cache/gstreamer-1.0/registry.*.bin

Requires Rust 1.70+, GStreamer 1.20+ dev libraries, and libamvenc.so

on the target system.

Usage:

  # Encode test pattern to H265

  gst-launch-1.0 videotestsrc num-buffers=300 \

    ! video/x-raw,format=NV12,width=1920,height=1080,framerate=25/1 \

    ! amlvenc_rs codec=h265 bitrate=2000000 \

    ! filesink location=out.h265

  # HW transcode H264 to H265

  gst-launch-1.0 filesrc location=input.h264 \

    ! h264parse ! amlvdec_rs framerate=25 \

    ! amlvenc_rs codec=h265 bitrate=2000000 \

    ! filesink location=out.h265

  # RTSP camera transcode

  gst-launch-1.0 rtspsrc location=rtsp://... latency=100 \

    ! rtph264depay ! h264parse \

    ! amlvdec_rs framerate=25 \

    ! amlvenc_rs codec=h265 \

    ! filesink location=out.h265

Performance (1080p NV12, 2Mbps H265, 1000 frames):

  Encode-only:  11.3s wall, 2.3s CPU (matches aml_enc_test)

  HW transcode: 15.7s wall, 9.0s CPU (decode + encode)

  Per-frame:    15.7ms encode, 2.5x real-time headroom at 25fps

The V4L2 decoder driver accounts for most of the transcode overhead

(8.5ms/frame in ioctl calls). The encoder itself has no measurable

overhead vs the vendor CLI tool.

Known issues:

  If the encoder process is killed (SIGKILL, timeout, OOM), the VPU

  hardware enters a broken state that persists until reboot. Always

  stop pipelines with SIGINT. Delete /tmp/vpu_mutex.map after crashes.