OvenMediaEngine supports GPU-based hardware decoding and encoding. Currently supported GPU acceleration devices are Intel's QuickSync and NVIDIA. This article explains how to install the drivers for OvenMediaEngine and set up the configuration to use your GPU.

1. Install Drivers

(curl -LOJ https://github.com/AirenSoft/OvenMediaEngine/archive/master.tar.gz && tar xvfz OvenMediaEngine-master.tar.gz)
OvenMediaEngine-master/misc/install_nvidia_driver.sh

$ nvidia-smi

Thu Jun 17 10:20:23 2021
+-----------------------------------------------------------------------------+
| NVIDIA-SMI 465.19.01    Driver Version: 465.19.01    CUDA Version: 11.3     |
|-------------------------------+----------------------+----------------------+
| GPU  Name        Persistence-M| Bus-Id        Disp.A | Volatile Uncorr. ECC |
| Fan  Temp  Perf  Pwr:Usage/Cap|         Memory-Usage | GPU-Util  Compute M. |
|                               |                      |               MIG M. |
|===============================+======================+======================|
|   0  NVIDIA GeForce ...  Off  | 00000000:01:00.0 Off |                  N/A |
| 20%   35C    P8    N/A /  75W |    156MiB /  1997MiB |      0%      Default |
|                               |                      |                  N/A |
+-------------------------------+----------------------+----------------------+

OvenMediaEngine-master/misc/prerequisites.sh --enable-nvc

OvenMediaEngine-master/misc/install_nvidia_docker_container.sh

OvenMediaEngine-master/Dockerfile.cuda
OvenMediaEngine-master/Dockerfile.cuda.local

(curl -LOJ https://github.com/AirenSoft/OvenMediaEngine/archive/master.tar.gz && tar xvfz OvenMediaEngine-master.tar.gz) 
OvenMediaEngine-master/misc/install_intel_driver.sh

# Use the samples provided in the Intel Media SDK
# Check the list of codecs supported by iGPU
/MediaSDK-intel-mediasdk-21.1.2/build/__bin/release/simple_7_codec

OvenMediaEngine-master/misc/prerequisites.sh --enable-qsv

2. Build & Run

Please refer to the link for how to build and run.

docker run -d ... --gpus all airensoft/ovenmediaengine:dev

3. Configuration

To use hardware acceleration, set the HardwareAcceleration option to true under OutputProfiles. If this option is enabled, a hardware codec is automatically used when creating a stream, and if it is unavailable due to insufficient hardware resources, it is replaced with a software codec.

<VirtualHosts>
   <VirtualHost>
      <Name>default</Name>
      ...
      <!-- Settings for applications -->
      <Applications>
         <Application>
            <Name>app</Name>
            <Type>live</Type>
            <OutputProfiles>
               <!-- Settings to use hardware codecs -->
               <HardwareAcceleration>true</HardwareAcceleration>
               <OutputProfile>
                  ...
               </OutputProfile>
               <OutputProfile>
                  ...
               </OutputProfile>
            </OutputProfiles>
            <Providers>
               ...
            </Providers>
            <Publishers>
               ...
            </Publishers>
         </Application>
      </Applications>
   </VirtualHost>
</VirtualHosts>

Appendix. Support Format

The codecs available using hardware accelerators in OvenMediaEngine are as shown in the table below. Different GPUs support different codecs. If the hardware codec is not available, you should check if your GPU device supports the codec.

D : Decoding, E : Encoding

Reference

• Quick Sync Video Format : https://en.wikipedia.org/wiki/Intel_Quick_Sync_Video

• NVIDIA NVDEC Video Format : https://en.wikipedia.org/wiki/Nvidia_NVDEC

• NVIDIA NVENV Video Format : https://en.wikipedia.org/wiki/Nvidia_NVENC

• CUDA Toolkit Installation Guide : https://docs.nvidia.com/cuda/cuda-installation-guide-linux/index.html#introduction

• NVIDIA Container Toolkit : https://docs.nvidia.com/datacenter/cloud-native/container-toolkit/arch-overview.html#arch-overview

• Quick Sync Video format support: https://en.wikipedia.org/wiki/Intel_Quick_Sync_Video

OvenMediaEngine has a built-in live transcoder. The live transcoder can decode the incoming live source and re-encode it with the set codec or adjust the quality to encode at multiple bitrates.

Supported Video, Audio and Image Codecs

Decoders

Encoders

OutputProfiles

OutputProfile

The <OutputProfile> setting allows incoming streams to be re-encoded via the <Encodes> setting to create a new output stream. The name of the new output stream is determined by the rules set in <OutputStreamName>, and the newly created stream can be used according to the streaming URL format.

<OutputProfiles>
    <OutputProfile>
        <Name>bypass_stream</Name>
        <OutputStreamName>${OriginStreamName}_bypass</OutputStreamName>
        <Encodes>
            <Video>
                <Bypass>true</Bypass>
            </Video>
            <Audio>
                <Bypass>true</Bypass>
            </Audio>            
            <Audio>
                <Codec>opus</Codec>
                <Bitrate>128000</Bitrate>
                <Samplerate>48000</Samplerate>
                <Channel>2</Channel>
            </Audio>
        </Encodes>
    </OutputProfile>
</OutputProfiles>

According to the above setting, if the incoming stream name is stream, the output stream becomes stream_bypassand the stream URL can be used as follows.

• WebRTC ws://192.168.0.1:3333/app/stream_bypass

• LLHLS http://192.168.0.1:8080/app/stream_bypass/llhls.m3u8

Encodes

Video

You can set the video profile as below:

<Encodes>
    <Video>
        <Name>h264_hd</Name>
        <Codec>h264</Codec>
        <Width>1280</Width>
        <Height>720</Height>
        <Bitrate>2000000</Bitrate>
        <Framerate>30.0</Framerate>
        <KeyFrameInterval>30</KeyFrameInterval>
        <BFrames>0</BFrames>
        <Preset>fast</Preset>
        <ThreadCount>4</ThreadCount>
    </Video>
</Encodes>

The meaning of each property is as follows:

* required

Table of presets

A table in which presets provided for each codec library are mapped to OvenMediaEngine presets. Slow presets are of good quality and use a lot of resources, whereas Fast presets have lower quality and better performance. It can be set according to your own system environment and service purpose.

References

• https://trac.ffmpeg.org/wiki/Encode/VP8

• https://docs.nvidia.com/video-technologies/video-codec-sdk/nvenc-preset-migration-guide/

Audio

You can set the audio profile as below:

<Encodes>
    <Audio>
        <Name>opus_128</Name>
        <Codec>opus</Codec>
        <Bitrate>128000</Bitrate>
        <Samplerate>48000</Samplerate>
        <Channel>2</Channel>
    </Audio>
</Encodes>

The meaning of each property is as follows:

* required

It is possible to have an audio only output profile by specifying the Audio profile and omitting a Video one.

Image

You can set the Image profile as below:

<Encodes>
    <Image>
        <Codec>jpeg</Codec>
        <Width>1280</Width>
        <Height>720</Height>
        <Framerate>1</Framerate>
    </Image>
</Encodes>

The meaning of each property is as follows:

Bypass without transcoding

You can configure Video and Audio to bypass transcoding as follows:

<Video>
    <Bypass>true</Bypass>
</Video>
<Audio>
    <Bypass>true</Bypass>
</Audio>

WebRTC doesn't support AAC, so if video bypasses transcoding, audio must be encoded in OPUS.

<Encodes>
    <Video>
        <Bypass>true</Bypass>
    </Video>
    <Audio>
        <Codec>opus</Codec>
        <Bitrate>128000</Bitrate>
        <Samplerate>48000</Samplerate>
        <Channel>2</Channel>
    </Audio>
</Encodes>

Conditional transcoding

If the codec or quality of the input stream is the same as the profile to be encoded into the output stream. there is no need to perform re-transcoding while unnecessarily consuming a lot of system resources. If the quality of the input track matches all the conditions of BypassIfMatch, it will be Pass-through without encoding

Matching elements in video

* eq: equal to / lte: less than or equal to / gte: greater than or equal to

Matching elements in audio

* eq: equal to / lte: less than or equal to / gte: greater than or equal to

To support WebRTC and LLHLS, AAC and Opus codecs must be supported at the same time. Use the settings below to reduce unnecessary audio encoding.

<Encodes>
	<Video>
                <Bypass>true</Bypass>	
	</Video>
	<Audio>
		<Name>cond_audio_aac</Name>
		<Codec>aac</Codec>
		<Bitrate>128000</Bitrate>
		<Samplerate>48000</Samplerate>
		<Channel>2</Channel>
		<BypassIfMatch>
			<Codec>eq</Codec>
			<Samplerate>lte</Samplerate>
			<Channel>eq</Channel>			
		</BypassIfMatch>
	</Audio>		
	<Audio>
		<Name>cond_audio_opus</Name>
		<Codec>opus</Codec>
		<Bitrate>128000</Bitrate>
		<Samplerate>48000</Samplerate>
		<Channel>2</Channel>
		<BypassIfMatch>
			<Codec>eq</Codec>
			<Samplerate>lte</Samplerate>
			<Channel>eq</Channel>	
		</BypassIfMatch>	
	</Audio>
</Encodes>

If a video track with a lower quality than the encoding option is input, unnecessary upscaling can be prevented. SAR (Storage Aspect Ratio) is the ratio of original pixels. In the example below, even if the width and height of the original video are smaller than or equal to the width and height set in the encoding option, if the ratio is different, it means that encoding is performed without bypassing.

<Encodes>
	<Video>                                                                                                    
		<Name>prevent_upscaling_video</Name>
		<Codec>h264</Codec>
		<Bitrate>2048000</Bitrate>
		<Width>1280</Width>
		<Height>720</Height>
		<Framerate>30</Framerate>
		<BypassIfMatch>
			<Codec>eq</Codec>
			<Width>lte</Width>
			<Height>lte</Height>
			<SAR>eq</SAR>
		</BypassIfMatch>
	</Video>
</Encodes>

Keep the original with transcoding

If you want to transcode with the same quality as the original. See the sample below for possible parameters that OME supports to keep original. If you remove the Width, Height, Framerate, Samplerate, and Channel parameters. then, It is transcoded with the same options as the original.

<Encodes>
    <Video>
        <Codec>vp8</Codec>
        <Bitrate>2000000</Bitrate>
    </Video>
     <Audio>
        <Codec>opus</Codec>
        <Bitrate>128000</Bitrate>
    </Audio>  
    <Image>
        <Codec>jpeg</Codec>
    </Image>
</Encodes>

Rescaling while keep the aspect ratio

To change the video resolution when transcoding, use the values of width and height in the Video encode option. If you don't know the resolution of the original, it will be difficult to keep the aspect ratio after transcoding. Please use the following methods to solve these problems. For example, if you input only the Width value in the Video encoding option, the Height value is automatically generated according to the ratio of the original video.

<Encodes>
    <Video>
        <Codec>h264</Codec>
        <Bitrate>2000000</Bitrate>
        <Width>1280</Width>
        <!-- Height is automatically calculated as the original video ratio -->
        <Framerate>30.0</Framerate>
    </Video>
    <Video>
        <Codec>h264</Codec>
        <Bitrate>2000000</Bitrate>
        <!-- Width is automatically calculated as the original video ratio -->
        <Height>720</Height>
        <Framerate>30.0</Framerate>
    </Video>    
</Encodes>

Adaptive Bitrate Streaming (ABR)

From version 0.14.0, OvenMediaEngine can encode same source with multiple bitrates renditions and deliver it to the player.

As shown in the example configuration below, you can provide ABR by adding <Playlists> to <OutputProfile>. There can be multiple playlists, and each playlist can be accessed with <FileName>.

The method to access the playlist set through LLHLS is as follows.

http[s]://<domain>[:port]/<app>/<stream>/<FileName>.m3u8

The method to access the Playlist set through WebRTC is as follows.

ws[s]://<domain>[:port]/<app>/<stream>/<FileName>

Note that <FileName> must never contain the playlist and chunklist keywords. This is a reserved word used inside the system.

To set up <Rendition>, you need to add <Name> to the elements of <Encodes>. Connect the set <Name> into <Rendition><Video> or <Rendition><Audio>.

In the example below, three quality renditions are provided and the URL to play the abr playlist as LLHLS is https://domain:port/app/stream/abr.m3u8 and The WebRTC playback URL is wss://domain:port/app/stream/abr

<OutputProfile>
	<Name>bypass_stream</Name>
	<OutputStreamName>${OriginStreamName}</OutputStreamName>
	<!--LLHLS URL : https://domain/app/stream/abr.m3u8 --> 
	<Playlist>
		<Name>For LLHLS</Name>
		<FileName>abr</FileName>
		<Options> <!-- Optinal -->
			<!-- 
			Automatically switch rendition in WebRTC ABR 
			[Default] : true
			-->
			<WebRtcAutoAbr>true</WebRtcAutoAbr> 
		</Options>
		<Rendition>
			<Name>Bypass</Name>
			<Video>bypass_video</Video>
			<Audio>bypass_audio</Audio>
		</Rendition>
		<Rendition>
			<Name>FHD</Name>
			<Video>video_1280</Video>
			<Audio>bypass_audio</Audio>
		</Rendition>
		<Rendition>
			<Name>HD</Name>
			<Video>video_720</Video>
			<Audio>bypass_audio</Audio>
		</Rendition>
	</Playlist>
	<!--LLHLS URL : https://domain/app/stream/llhls.m3u8 --> 
	<Playlist>
		<Name>Change Default</Name>
		<FileName>llhls</FileName>
		<Rendition>
			<Name>HD</Name>
			<Video>video_720</Video>
			<Audio>bypass_audio</Audio>
		</Rendition>
	</Playlist> 
	<Encodes>
		<Audio>
			<Name>bypass_audio</Name>
			<Bypass>true</Bypass>
		</Audio>
		<Video>
			<Name>bypass_video</Name>
			<Bypass>true</Bypass>
		</Video>
		<Audio>
			<Codec>opus</Codec>
			<Bitrate>128000</Bitrate>
			<Samplerate>48000</Samplerate>
			<Channel>2</Channel>
		</Audio>
		<Video>
			<Name>video_1280</Name>
			<Codec>h264</Codec>
			<Bitrate>5024000</Bitrate>
			<Framerate>30</Framerate>
			<Width>1920</Width>
			<Height>1280</Height>
			<Preset>faster</Preset>
		</Video>
		<Video>
			<Name>video_720</Name>
			<Codec>h264</Codec>
			<Bitrate>2024000</Bitrate>
			<Framerate>30</Framerate>
			<Width>1280</Width>
			<Height>720</Height>
			<Preset>faster</Preset>
		</Video>
	</Encodes>
</OutputProfile>

Supported codecs by streaming protocol

Even if you set up multiple codecs, there is a codec that matches each streaming protocol supported by OME, so it can automatically select and stream codecs that match the protocol. However, if you don't set a codec that matches the streaming protocol you want to use, it won't be streamed.

The following is a list of codecs that match each streaming protocol:

Therefore, you set it up as shown in the table. If you want to stream using LLHLS, you need to set up H.264 and AAC, and if you want to stream using WebRTC, you need to set up Opus.

Also, if you are going to use WebRTC on all platforms, you need to configure both VP8 and H.264. This is because different codecs are supported for each browser, for example, VP8 only, H264 only, or both.

However, don't worry. If you set the codecs correctly, OME automatically sends the stream of codecs requested by the browser.