MJPEG Server
MJPEG Server implements
MJPEG over HTTP
using FFmpeg or any other input source capable of piping
a multipart JPEG stream to stdout.
Its primary use case is providing screen recordings for remote Webdriver tests,
e.g. for blueimp/wdio.
It is resource efficient and by default only starts the screen recording process
if there is at least one HTTP client connected to the server, stopping the
recording when there are no more open client connections.
Installation
The MJPEG Server binary can be downloaded for Linux, MacOS and Windows from the
releases page or built from
source via go get:
go get github.com/blueimp/mjpeg-server
The screencast examples also require FFmpeg to be
installed.
Usage
By default, mjpeg-server
listens on port 9000
on all interfaces and starts
the given recording command when the first HTTP client connects:
mjpeg-server [options] [--] command [args]
The command
must write a multipart JPEG stream to stdout, e.g.:
--ffmpeg
Content-Type: image/jpeg
[IMAGE_DATA]
--ffmpeg
Content-Type: image/jpeg
[IMAGE_DATA]
...
--ffmpeg--
A sample multipart JPEG generation program can be tested by running the
following command and opening http://localhost:9000 in your browser:
go run main.go -a 127.0.0.1:9000 -- go run mpjpeg/main.go -- gopher.jpg
It simply streams the provided JPEG images in an endless loop.
Options
Available MJPEG Server options can be listed the following way:
mjpeg-server -h
Usage of mjpeg-server:
-a string
TCP listen address (default ":9000")
-b string
Multipart boundary (default "ffmpeg")
-d Start command directly
-p string
URL path (default "/")
-v Output version and exit
The -d
option starts the given recording command directly on initialization of
the MJPEG server and keeps it running independently of the number of connected
HTTP clients, until the MJPEG server process is stopped.
Screencast
Linux
Start mjpeg-server
using the
x11grab device, selecting
the X11 display via -i :DISPLAY
and the matching screen resolution via
-video_size WIDTHxHEIGHT
option:
mjpeg-server -- ffmpeg \
-loglevel fatal \
-probesize 32 \
-fpsprobesize 0 \
-analyzeduration 0 \
-fflags nobuffer \
-f x11grab \
-r 15 \
-video_size 1440x900 \
-i :0 \
-f mpjpeg \
-q 2 \
-
MacOS
List the available
avfoundation input
devices:
ffmpeg -f avfoundation -list_devices true -i -
Start mjpeg-server
, selecting the capture device via -i INDEX
option:
mjpeg-server -- ffmpeg \
-loglevel error \
-probesize 32 \
-fpsprobesize 0 \
-analyzeduration 0 \
-fflags nobuffer \
-f avfoundation \
-capture_cursor 1 \
-r 15 \
-pixel_format yuyv422 \
-i 1 \
-f mpjpeg \
-q 2 \
-
Windows
On Windows, we can use the built-in
gdigrab input device to
capture the whole desktop.
Start MJPEGServer
using the following command in a Powershell console:
MJPEGServer -- ffmpeg `
-loglevel error `
-probesize 32 `
-fpsprobesize 0 `
-analyzeduration 0 `
-fflags nobuffer `
-f gdigrab `
-r 15 `
-i desktop `
-f mpjpeg `
-q 2 `
-
License
Released under the MIT license.
Attributions
The Gopher image used for the tests was designed by
Renee French.
The design is licensed under the
Creative Commons 3.0 Attributions license.
Author
Sebastian Tschan