Aurora4 Sample Encoder

Introduction to the aurora4_sample_encoder

aurora4_sample_encoder is a simple encoder program demonstrating the use of the Aurora4 API.

The usage of aurora4_sample_encoder is shown as below:

Usage: ./aurora4_sample_encoder <preset> <tune> <width> <height> <depth> <fps-num> <in-yuv> <outfile> <keyframe-interval> <rc-type> <target-bitrate/crf/qp/quality> <threads> <frames to encode> [wz4-params] [debug-log]

preset: ultrafast superfast veryfast faster fast medium slow slower veryslow superslow
tune: default psnr ssim vmaf screen movie game zerolatency universe film grain animation stillimage arm fastdecode mpass

You can find more details listed as below for each parameter

  preset            <string>     ..... Set preset (supported presets listed in aurora4enc.h) parameter    
  tune              <string>     ..... Set tune(default psnr ssim vmaf screen movie game zerolatency universe film grain animation stillimage arm fastdecode mpass) parameter
  width             <int>        ..... Set frame width
  height            <int>        ..... Set frame height
  fps-num           <int>        ..... Set frame per seconds (from 1 to 120)
  in-yuv            <string>     ..... Set path of encoding sequence (only yuv is supported)
  outfile           <string>     ..... Set path of output file
  keyframe-interval <int>        ..... Set maximum keyframe intervals
  rc-type           <int>        ..... Set rate control type(-1:quality, 0: cqp, 1: crf, 2: abr) parameter
  target-bitrate/crf/qp/quality  <float>
                                 ..... Set target-bitrate(kbps) or crf values(from 1 to 51) or qp values(from 1 to 51) or quality (from 1 to 5)
  threads           <int>        ..... Set threads
  frames to encode  <int>        ..... Set frames to be encoded (from -1 to int_MAX, -1 means maximal availabe frames)
  wz264-params      <string>     ..... Set extra configurations (use ":" to separate different params)
  debug-log         <int>        ..... Set whether output debug logs or not (1: enable, 0: disable, default is 0), can be skipped

The executable is build from the file aurora4_sample_encoder.c and header files declaring the API functions and the relevant structures.

The encoder is built from wz4_enc_cfg_t which exposes the core parameters needed to set up the encoder.
Parameters can be modified before each encode call by updating the configuration, but this may cause the encoder to be reset in some cases.
A list of all the parameters that can be passed using the configuration string wz4_enc_cfg_t and wz264-params can be found here.
Further explanations for -preset and -tune in the table above are provided in the Presets and Tuning Options

Building the aurora4_sample_encoder

Step 1: The encoding configuration can be modified as per your requirements and for all possible options, please refer to samples/aurora4_sample_encoder.c. For example, parameters such as vbv_max_bitrate, vbv_buffer_size etc. can be reset according to your requirements.

Step 2: Build your own sample encoder by running the following -

Build: gcc samples/aurora4_sample_encoder.c -I include/ -L lib/ -laurora4 -o aurora4_sample_encoder

Run: LD_LIBRARY_PATH=`pwd`/lib/ ./aurora4_sample_encoder ...

Running the aurora4_sample_encoder

Here are some examples of running the aurora4_sample_encoder in different rate-control modes.

Constant quality mode is more suitable for on-demand application scenarios.

LD_LIBRARY_PATH=`pwd`/lib/ ./bin/aurora4_sample_encoder slow default 1920 1080 8 30 input.yuv output.264 300 1 30 4 1000

Averaged bitrate mode is more suitable for live broadcast application scenarios.

LD_LIBRARY_PATH=`pwd`/lib/ ./bin/aurora4_sample_encoder fast default 1920 1080 8 30 input.yuv output.264 90 2 3000 8 1000 bframes=7:rc-lookahead=16 0

Constant bitrate mode is more suitable for RTC application scenarios.

LD_LIBRARY_PATH=`pwd`/lib/ ./bin/aurora4_sample_encoder veryfast zerolatency 1920 1080 8 30 input.yuv output.264 1000 3 2000 4 1000