Initial Configuration

SDL Core Setup

Before continuing, follow the Install and Run Guide for SDL Core if you have not already done so.

HMI Setup

The Generic HMI and SDL HMI both support streaming audio and some video formats in the browser using ffmpeg to transcode the video to VP8 WEBM or audio to WAV. Instructions to install the required dependencies can be found in the HMI README:

• SDL HMI Dependencies
• Generic HMI Dependencies

Prior to starting the HMI, you will need to run the backend server component (./deploy_server.sh in the HMI directory) which handles the transcoding process.

Note

Once you start a video stream it will take a few seconds for the transcoding session to begin. Your video stream should appear in the browser within about 10 seconds.

To stream without ffmpeg transcoding, or to stream a format that ffmpeg does not support, you can forgo starting the backend server and use gstreamer to consume your audio/video stream.

GSTREAMER Setup

It is easier to determine which gstreamer video sink will work in your environment by testing with a static file. This can be done by downloading this file and trying the following command.

Common values for sink:

• ximagesink (x visual environment sink)
• xvimagesink (xv visual environment sink)
• cacasink (ascii art sink)

gst-launch-1.0 filesrc location=/path/to/h264/file ! decodebin ! videoconvert ! <sink> sync=false

If you're streaming video over TCP, you can point gstreamer directly to your phone's stream using

gst-launch-1.0 tcpclientsrc host=<Device IP Address> port=3000 ! decodebin ! videoconvert ! <sink> sync=false

Pipe Streaming

Configuration (smartDeviceLink.ini)

In the Core build folder, open bin/smartDeviceLink.ini and ensure the following values are set:

VideoStreamConsumer = pipe
AudioStreamConsumer = pipe

GStreamer Commands

After you start SDL Core, cd into the bin/storage directory and there should be a file named "video_stream_pipe". Use the gst-launch command that worked for your environment and set file source to the video_stream_pipe file. You should see “setting pipeline to PAUSED” and “Pipeline is PREROLLING”.

Raw H.264 Video

gst-launch-1.0 filesrc location=$SDL_BUILD_PATH/bin/storage/video_stream_pipe ! decodebin ! videoconvert ! xvimagesink sync=false

H.264 Video over RTP

gst-launch-1.0 filesrc location=$SDL_BUILD_PATH/bin/storage/video_stream_pipe ! "application/x-rtp-stream" ! rtpstreamdepay ! "application/x-rtp,media=(string)video,clock-rate=90000,encoding-name=(string)H264" ! rtph264depay ! "video/x-h264, stream-format=(string)avc, alignment=(string)au" ! avdec_h264 ! videoconvert ! ximagesink sync=false

RAW PCM Audio

gst-launch-1.0 filesrc location=$SDL_BUILD_PATH/bin/storage/audio_stream_pipe ! audio/x-raw,format=S16LE,rate=16000,channels=1 ! pulsesink

Socket Streaming

Configuration (smartDeviceLink.ini)

In the Core build folder, open bin/smartDeviceLink.ini and ensure the following values are set:

; Socket ports for video and audio streaming
VideoStreamingPort = 5050
AudioStreamingPort = 5080
...
VideoStreamConsumer = socket
AudioStreamConsumer = socket

GStreamer Commands

Raw H.264 Video

gst-launch-1.0 souphttpsrc location=http://127.0.0.1:5050 ! decodebin ! videoconvert ! xvimagesink sync=false

H.264 Video over RTP

gst-launch-1.0 souphttpsrc location=http://127.0.0.1:5050 ! "application/x-rtp-stream" ! rtpstreamdepay ! "application/x-rtp,media=(string)video,clock-rate=90000,encoding-name=(string)H264" ! rtph264depay ! "video/x-h264, stream-format=(string)avc, alignment=(string)au" ! avdec_h264 ! videoconvert ! ximagesink sync=false

RAW PCM Audio

gst-launch-1.0 souphttpsrc location=http://127.0.0.1:5080 ! audio/x-raw,format=S16LE,rate=16000,channels=1 ! pulsesink

Video Streaming States

This section describes how Core manages the streaming states of mobile applications. Only one application may stream video at a time, but audio applications may stream while in the LIMITED state with other applications.

When an app is moved to HMI level FULL:

• All non-streaming applications go to HMI level BACKGROUND
• All apps with the same App HMI Type go to BACKGROUND
• Streaming apps with a different App HMI Type that were in FULL go to LIMITED

When an app is moved to HMI level LIMITED:

• All non-streaming applications keep their HMI level
• All applications with a different App HMI Type keep their HMI level
• Applications with the same App HMI Type go to BACKGROUND

Additional Resources

Note

Livio provides an example video streaming android application.

iOS Video Streaming Guide

Android Video Streaming Guide