# openh264

**Repository Path**: HarmonyOS-tpc/openh264

## Basic Information

- **Project Name**: openh264
- **Description**: No description available
- **Primary Language**: Unknown
- **License**: BSD-2-Clause
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 1
- **Forks**: 0
- **Created**: 2021-09-17
- **Last Updated**: 2023-04-17

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

openh264
===============

## Introduction
OpenH264 is a codec library which supports H.264 encoding and decoding. It is suitable for use in real time applications such as WebRTC. See http://www.openh264.org/ for more details.

## Usage Instructions

Encoder Features
- Constrained Baseline Profile up to Level 5.2 (Max frame size is 36864 macro-blocks)
- Arbitrary resolution, not constrained to multiples of 16x16
- Rate control with adaptive quantization, or constant quantization
- Slice options: 1 slice per frame, N slices per frame, N macroblocks per slice, or N bytes per slice
- Multiple threads automatically used for multiple slices
- Temporal scalability up to 4 layers in a dyadic hierarchy
- Simulcast AVC up to 4 resolutions from a single input
- Spatial simulcast up to 4 resolutions from a single input
- Long Term Reference (LTR) frames
- Memory Management Control Operation (MMCO)
- Reference picture list modification
- Single reference frame for inter prediction
- Multiple reference frames when using LTR and/or 3-4 temporal layers
- Periodic and on-demand Instantaneous Decoder Refresh (IDR) frame insertion
- Dynamic changes to bit rate, frame rate, and resolution
- Annex B byte stream output
- YUV 4:2:0 planar input

Decoder Features
----------------
- Constrained Baseline Profile up to Level 5.2 (Max frame size is 36864 macro-blocks)
- Arbitrary resolution, not constrained to multiples of 16x16
- Single thread for all slices
- Long Term Reference (LTR) frames
- Memory Management Control Operation (MMCO)
- Reference picture list modification
- Multiple reference frames when specified in Sequence Parameter Set (SPS)
- Annex B byte stream input
- YUV 4:2:0 planar output

## Installation Instructions
```
steps to build native code:
a) Copy openh264 folder to linux machine
b) To build You need to install sdk and ndk. You also need to export `**SDK**/tools` to PATH. On Linux, this can be done by

    export PATH=**SDK**/tools:$PATH

The codec and demo can be built by

    make OS=**OS** NDKROOT=**NDK** TARGET=**TARGET**

Valid `**TARGET**` can be found in `**SDK**/platforms`.
You can also set `ARCH`, `NDKLEVEL` according to your device and NDK version.
`ARCH` specifies the architecture of device. Currently `arm`, `arm64`, `x86` and `x86_64` are supported, the default is `arm`. (`mips` and `mips64` can also be used, but there's no specific optimization for those architectures.)
`NDKLEVEL` specifies api level, the default is 12. Available possibilities can be found in `**NDK**/platforms`

By default these commands build for the `armeabi-v7a` ABI. To build for the other
ABIs, add `ARCH=arm64`, `ARCH=x86`, `ARCH=x86_64`, `ARCH=mips` or `ARCH=mips64`.
To build for the older `armeabi` ABI (which has armv5te as baseline), add `APP_ABI=armeabi` (`ARCH=arm` is implicit).
To build for 64-bit ABI, such as `arm64`, explicitly set `NDKLEVEL` to 21 or higher.

c) libopenh264.so and libstport.so files will be genrated

steps to generate libencoding.so and libdecoding.so file to sample app.
a) Create .cpp files for encoding, auto encoding and decoding fetures in src/main/cpp directory of the entry
b) place liopenh264.so file in src/main/cpp/lib/arm64-v8a folder
b) Create CMakeLists.txt to build native code and create shared library libencoding.so and libdecoding.so.
c) Add below native build configuration in build file of entry.

	externalNativeBuild {
        path "src/main/cpp/CMakeLists.txt"
        arguments "-v"
        abiFilters "arm64-v8a"
    }

steps to build sample app:
a) place libencoding.so, libdecoding.so, libopenh264.so, libc++.so and libstlport.so in /entry/libs/arm64-v8a
b) load libencoding.so, libdecoding.so, libopenh264.so and libstlport.so in sample app
c) check the sample app for implementation

d) For using openh264 library from a remote repository in separate application, add the below dependency in entry/build.gradle file.
     
dependencies {
    implementation 'io.openharmony.tpc.thirdlib:openh264:1.0.0'
}

```

## LICENSE
-------
BSD, see `LICENSE` file for details.