HVE - Hardware Video Encoder C library

This library wraps hardware video encoding and scaling in a simple interface. There are no performance loses (at the cost of library flexibility).

Currently it supports VAAPI and various codecs (H.264, HEVC, ...).\ VBR and CQP modes are supported (e.g. streaming and later editting).

See library documentation.

See also twin HVD Hardware Video Decoder library.

See hardware-video-streaming for other related projects.

Intended Use

Raw encoding (H264, HEVC, ...):

• custom network streaming protocols
• low latency streaming
• raw dumping (H264, HEVC, ...)
• ...

Complex pipelines (muxing, filtering) are beyond the scope of this library.

Platforms

Unix-like operating systems (e.g. Linux). Tested on Ubuntu 18.04.

Hardware

Intel VAAPI compatible hardware encoders (Quick Sync Video)

Dependencies

Library depends on:

• FFmpeg avcodec, avutil, avfilter (at least 3.4 version)

Works with system FFmpeg on Ubuntu 18.04 and doesn't on 16.04 (outdated FFmpeg and VAAPI ecosystem).

Building Instructions

Tested on Ubuntu 18.04.

# update package repositories
sudo apt-get update 
# get avcodec and avutil (and ffmpeg for testing)
sudo apt-get install ffmpeg libavcodec-dev libavutil-dev libavfilter-dev
# get compilers and make and cmake
sudo apt-get install build-essential
# get cmake - we need to specify libcurl4 for Ubuntu 18.04 dependencies problem
sudo apt-get install libcurl4 cmake
# get git
sudo apt-get install git
# clone the repository
git clone https://github.com/bmegli/hardware-video-encoder.git

# finally build the library and examples
cd hardware-video-encoder
mkdir build
cd build
cmake ..
make

Running Examples

# ./hve-encode-raw-h264 <number-of-seconds> [device]
./hve-encode-raw-h264 10

# ./hve-encode-raw-hevc10 <number-of-seconds> [device]
./hve-encode-raw-hevc10 10

If you get errors see troubleshooting.

Testing

Play result raw H.264/HEVC file with FFmpeg:

# output goes to output.h264/output.hevc file
ffplay output.h264
ffplay output.hevc

You should see procedurally generated video (moving through greyscale).

Using

See examples directory for more complete and commented examples with error handling.

There are just 4 functions and 3 user-visible data types:

• hve_init
• hve_send_frame (sends uncompressed data to hardware)
• hve_receive_packet (retrieves compressed data from hardware)
• hve_close

struct hve_config hardware_config = {WIDTH, HEIGHT, INPUT_WIDTH, INPUT_HEIGHT, FRAMERATE,
                                     DEVICE, ENCODER, PIXEL_FORMAT, PROFILE, BFRAMES,
                                    BITRATE, QP, GOP_SIZE, COMPRESSION_LEVEL, LOW_POWER};

struct hve *hardware_encoder=hve_init(&hardware_config);
struct hve_frame frame = { 0 };

//later assuming PIXEL_FORMAT is "nv12" (you may use something else)

//fill with your stride (width including padding if any)
frame.linesize[0] = frame.linesize[1] = INPUT_WIDTH;

AVPacket *packet; //encoded data is returned in FFmpeg packet
int failed; //error indicator while encoding

//...
//whatever logic you have to prepare data source
//...

while(keep_encoding) 
{
    //...
    //update NV12 Y and color data (e.g. get them from camera)
    //...
    //fill hve_frame with pointers to your data in NV12 pixel format
    frame.data[0]=Y; //dummy luminance plane
    frame.data[1]=color; //dummy UV color plane
    //encode this frame
    hve_send_frame(hardware_encoder, &frame);
    while( (packet=hve_receive_packet(hardware_encoder, &failed)) )
    {
        //... 
        //packet.data is h.264 encoded frame of packet.size length
        //... so do something with it?
    }
}

//flush the encoder by sending NULL frame
hve_send_frame(hardware_encoder, NULL);
while( (packet=hve_receive_packet(hardware_encoder, &failed)) )
    ; //ignore last packets

hve_close(hardware_encoder);

That's it! You have just seen all the functions and data types in the library.

Compiling your code

You have several options.

IDE (recommended)

For static linking of HVE and dynamic linking of FFmpeg libraries (easiest):

• copy hve.h and hve.c to your project and add them in your favourite IDE
• add avcodec, avutil, avfilter to linked libraries in IDE project configuration

For dynamic linking of HVE and FFmpeg libraries:

• place hve.h where compiler can find it (e.g. make install for /usr/local/include/hve.h)
• place libhve.so where linker can find it (e.g. make install for /usr/local/lib/libhve.so)
• make sure /usr/local/... is considered for libraries
• add hve, avcodec, avutil, avfilter to linked libraries in IDE project configuration
• make sure libhve.so is reachable to you program at runtime (e.g. set LD_LIBRARIES_PATH)

CMake

Assuming directory structure with HVE as hardware-video-encoder subdirectory (or git submodule) of your project.

your-project
│   main.cpp
│   CMakeLists.txt
│
└───hardware-video-encoder
│   │   hve.h
│   │   hve.c
│   │   CMakeLists.txt

You may use the following top level CMakeLists.txt

cmake_minimum_required(VERSION 3.0)

project(
    your-project
)

# drop the SHARED if you would rather link with HVE statically
add_library(hve SHARED hardware-video-encoder/hve.c)

add_executable(your-project main.cpp)
target_include_directories(your-project PRIVATE hardware-video-encoder)
target_link_libraries(your-project hve avcodec avutil avfilter)

For example see realsense-ir-to-vaapi-h264

Manually

Assuming your main.c/main.cpp and hve.h, hve.c are all in the same directory:

C

gcc main.c hve.c -lavcodec -lavutil -lavfilter -o your-program

C++

gcc -c hve.c
g++ -c main.cpp
g++ hve.o main.o -lavcodec -lavutil -lavfilter -o your program

License

Library is licensed under Mozilla Public License, v. 2.0

This is similiar to LGPL but more permissive:

• you can use it as LGPL in prioprietrary software
• unlike LGPL you may compile it statically with your code

Like in LGPL, if you modify this library, you have to make your changes available. Making a github fork of the library with your changes satisfies those requirements perfectly.

Since you are linking to FFmpeg libraries consider also avcodec, avutil and avfilter licensing.

Additional information

Library uses

Realsense D400 camera infrared stream to H.264 - realsense-ir-to-vaapi-h264\ Realsense D400 camera depth stream to HEVC Main10 - realsense-depth-to-vaapi-hevc10