Sourcer API Parameters¶

source¶

This parameter defines the input source (-i) for probing.

Data-Type: String.

Its valid input can be one of the following:

• Filepath: Valid path of the video file, for e.g "/home/foo.mp4" as follows:

  # initialize the sourcer and probe it
  sourcer = Sourcer('/home/foo.mp4').probe_stream()
  

• Image Sequence: Valid image sequence such as sequential('img%03d.png') or glob pattern('*.png') or single (looping) image as input:

  SequentialGlob patternSingle (loop) image

  How to start with specific number image?

  You can use -start_number FFmpeg parameter if you want to start with specific number image:

  # define `-start_number` such as `5`
  sourcer_params = {"-ffprefixes":["-start_number", "5"]}
  
  # initialize the sourcer with define parameters
  sourcer = Sourcer('img%03d.png', verbose=True, **sourcer_params).probe_stream()
  

  # initialize the sourcer and probe it
  sourcer = Sourcer('img%03d.png', verbose=True).probe_stream()
  

  Bash-style globbing (* represents any number of any characters) is useful if your images are sequential but not necessarily in a numerically sequential order.

  The glob pattern is not available on Windows builds.

  # define `-pattern_type glob` for accepting glob pattern
  sourcer_params = {"-ffprefixes":["-pattern_type", "glob"]}
  
  # initialize the sourcer with define parameters and probe it
  sourcer = Sourcer('img*.png', verbose=True, **sourcer_params).probe_stream()
  

  # define `-loop 1` for looping
  sourcer_params = {"-ffprefixes":["-loop", "1"]}
  
  # initialize the sourcer with define parameters and probe it
  sourcer = Sourcer('img.jpg', verbose=True, **sourcer_params).probe_stream()
  

• Network Address: Valid (http(s), rtp, rstp, rtmp, mms, etc.) incoming network stream address such as 'rtsp://xx:yy@192.168.1.ee:fd/av0_0' as input:

  # define `rtsp_transport` or necessary parameters 
  sourcer_params = {"-ffprefixes":["-rtsp_transport", "tcp"]}
  
  # initialize the sourcer with define parameters and probe it
  sourcer = Sourcer('rtsp://xx:yy@192.168.1.ee:fd/av0_0', verbose=True, **sourcer_params).probe_stream()
  

• Camera Device Index: Valid "device index" or "camera index" of the connected Camera Device. For example, for using "0" index device as source on Windows, we can do as follows in Sourcer API:

  Requirement for using Camera Device as source in Sourcer API

  • MUST have appropriate FFmpeg binaries, Drivers, and Softwares installed:

    Internally, DeFFcode APIs achieves Index based Camera Device Capturing by employing some specific FFmpeg demuxers on different platforms(OSes). These platform specific demuxers are as follows:

    Platform(OS)	Demuxer
    Windows OS	dshow (or DirectShow)
    Linux OS	video4linux2 (or its alias v4l2)
    Mac OS	avfoundation

    Important: Kindly make sure your FFmpeg binaries support these platform specific demuxers as well as system have the appropriate video drivers and related softwares installed.

  • The source parameter value MUST be any Camera Device index that can be of either integer (e.g. -1,0,1, etc.) or string of integer (e.g. "-1","0","1", etc.) type.

  • The source_demuxer parameter value MUST be either None(also means empty) or "auto".

  # initialize the sourcer with "0" index source and probe it
  sourcer = Sourcer("0", verbose=True).probe_stream()
  

• Video Capture Devices: Valid video probe device's name (e.g. "USB2.0 Camera") or its path (e.g. "/dev/video0" on linux) or its index (e.g. "0") as input w.r.t source_demuxer parameter value in use. For example, for probing "USB2.0 Camera" named device with dshow source demuxer on Windows, we can do as follows in Sourcer API:

  Identifying and Specifying Device name/path/index and suitable Demuxer on different OSes

  Windows Linux MacOS

  Windows OS users can use the dshow (DirectShow) to list video input device which is the preferred option for Windows users. You can refer following steps to identify and specify your input video device's name:

  • Identify Video Devices: You can locate your video device's name (already connected to your system) using dshow as follows:

    c:\> ffmpeg.exe -list_devices true -f dshow -i dummy
    
    ffmpeg version N-45279-g6b86dd5... --enable-runtime-cpudetect
      libavutil      51. 74.100 / 51. 74.100
      libavcodec     54. 65.100 / 54. 65.100
      libavformat    54. 31.100 / 54. 31.100
      libavdevice    54.  3.100 / 54.  3.100
      libavfilter     3. 19.102 /  3. 19.102
      libswscale      2.  1.101 /  2.  1.101
      libswresample   0. 16.100 /  0. 16.100
    [dshow @ 03ACF580] DirectShow video devices
    [dshow @ 03ACF580]  "Integrated Camera"
    [dshow @ 03ACF580]  "USB2.0 Camera"
    [dshow @ 03ACF580] DirectShow audio devices
    [dshow @ 03ACF580]  "Microphone (Realtek High Definition Audio)"
    [dshow @ 03ACF580]  "Microphone (USB2.0 Camera)"
    dummy: Immediate exit requested
    

  • Specify Video Device's name: Then, you can specify and initialize your located Video device's name in Sourcer API as follows:

    # initialize the sourcer with "USB2.0 Camera" source and probe it
    sourcer = Sourcer("USB2.0 Camera", source_demuxer="dshow", verbose=True).probe_stream()
    

  • [OPTIONAL] Specify Video Device's index along with name: If there are multiple Video devices with similar name, then you can use -video_device_number parameter to specify the arbitrary index of the particular device. For instance, to open second video device with name "Camera" you can do as follows:

    # define video_device_number as 1 (numbering start from 0)
    sourcer_params = {"-ffprefixes":["-video_device_number", "1"]}
    
    # initialize the sourcer with "Camera" source and probe it
    sourcer = Sourcer("Camera", source_demuxer="dshow", verbose=True, **sourcer_params).probe_stream()
    

  Linux OS users can use the video4linux2 (or its alias v4l2) to list to all video capture devices such as from an USB webcam. You can refer following steps to identify and specify your probe video device's path:

  • Identify Video Devices: Linux systems tend to automatically create file device node/path when the device (e.g. an USB webcam) is plugged into the system, and has a name of the kind '/dev/videoN', where N is a index associated to the device. To get the list of all available file device node/path on your Linux machine, you can use the v4l-ctl command.

    You can use sudo apt install v4l-utils APT command to install v4l-ctl tool on Debian-based Linux distros.

    $ v4l2-ctl --list-devices
    
    USB2.0 PC CAMERA (usb-0000:00:1d.7-1):
            /dev/video1
    
    UVC Camera (046d:0819) (usb-0000:00:1d.7-2):
            /dev/video0
    

  • Specify Video Device's path: Then, you can specify and initialize your located Video device's path in Sourcer API as follows:

    # initialize the sourcer with "/dev/video0" source and probe it
    sourcer = Sourcer("/dev/video0", source_demuxer="v4l2", verbose=True).probe_stream()
    

  MacOS users can use the AVFoundation to list input devices and is the currently recommended framework by Apple for streamgrabbing on Mac OSX-10.7 (Lion) and later as well as on iOS. You can refer following steps to identify and specify your probe video device's name or index on MacOS/OSX machines:

  QTKit is also available for streamgrabbing on Mac OS X 10.4 (Tiger) and later, but has been marked deprecated since OS X 10.7 (Lion) and may not be available on future releases.

  • Identify Video Devices: Then, You can locate your Video device's name and index using avfoundation as follows:

    $ ffmpeg -f avfoundation -list_devices true -i ""
    
    ffmpeg version N-45279-g6b86dd5... --enable-runtime-cpudetect
      libavutil      51. 74.100 / 51. 74.100
      libavcodec     54. 65.100 / 54. 65.100
      libavformat    54. 31.100 / 54. 31.100
      libavdevice    54.  3.100 / 54.  3.100
      libavfilter     3. 19.102 /  3. 19.102
      libswscale      2.  1.101 /  2.  1.101
      libswresample   0. 16.100 /  0. 16.100
    [AVFoundation input device @ 0x7f8e2540ef20] AVFoundation video devices:
    [AVFoundation input device @ 0x7f8e2540ef20] [0] FaceTime HD camera (built-in)
    [AVFoundation input device @ 0x7f8e2540ef20] [1] Capture screen 0
    [AVFoundation input device @ 0x7f8e2540ef20] AVFoundation audio devices:
    [AVFoundation input device @ 0x7f8e2540ef20] [0] Blackmagic Audio
    [AVFoundation input device @ 0x7f8e2540ef20] [1] Built-in Microphone
    

  • Specify Video Device's name or index: Then, you can specify and initialize your located Video device in Sourcer API using its either the name or the index shown in the device listing:

    Using device's indexUsing device's name

    # initialize the sourcer with `1` index source and probe it
    sourcer = Sourcer("1", source_demuxer="avfoundation", verbose=True).probe_stream()
    

    When specifying device's name, abbreviations using just the beginning of the device name are possible. Thus, to probe from a device named "Integrated iSight-camera" just "Integrated" is sufficient:

    # initialize the sourcer with "Integrated iSight-camera" source 
    sourcer = Sourcer("Integrated", source_demuxer="avfoundation", verbose=True).probe_stream()
    

  If these steps doesn't work for you then reach us out on Gitter ➶ Community channel

  # initialize the sourcer with "USB2.0 Camera" source 
  sourcer = Sourcer("USB2.0 Camera", source_demuxer="dshow", verbose=True).probe_stream()
  

• Screen Capturing/Recording: Valid screen probe device's name (e.g. "desktop") or its index (e.g. ":0.0") as input w.r.t source_demuxer parameter value in use. For example, for probing "0:" indexed device with avfoundation source demuxer on MacOS, we can do as follows in Sourcer API:

  Specifying suitable Parameter(s) and Demuxer for Capturing your Desktop on different OSes

  Windows Linux MacOS

  Windows OS users can use the gdigrab to grab video from the Windows screen. You can refer following steps to specify source for probing:

  For Windows OS users dshow is also available for grabbing frames from your desktop. But it is highly unreliable and don't works most of the times.

  # define framerate
  sourcer_params = {"-framerate": "30"}
  
  # initialize the sourcer with "desktop" source and probe it
  sourcer = Sourcer("desktop", source_demuxer="gdigrab", verbose=True, **sourcer_params).probe_stream()
  

  Linux OS users can use the x11grab to probe an X11 display. You can refer following steps to specify source for probing:

  # initialize the sourcer with ":0.0" desktop source and probe it
  sourcer = Sourcer(":0.0", source_demuxer="x11grab", verbose=True).probe_stream()
  

  MacOS users can use the AVFoundation to list input devices and is the currently recommended framework by Apple for streamgrabbing on Mac OSX-10.7 (Lion) and later as well as on iOS. You can refer following steps to identify and specify your probe video device's name or index in Sourcer API:

  QTKit is also available for streamgrabbing on Mac OS X 10.4 (Tiger) and later, but has been marked deprecated since OS X 10.7 (Lion) and may not be available on future releases.

  You can enumerate all the available input devices including screens ready to be probed using avfoundation as follows:

  $ ffmpeg -f avfoundation -list_devices true -i ""
  
  ffmpeg version N-45279-g6b86dd5... --enable-runtime-cpudetect
    libavutil      51. 74.100 / 51. 74.100
    libavcodec     54. 65.100 / 54. 65.100
    libavformat    54. 31.100 / 54. 31.100
    libavdevice    54.  3.100 / 54.  3.100
    libavfilter     3. 19.102 /  3. 19.102
    libswscale      2.  1.101 /  2.  1.101
    libswresample   0. 16.100 /  0. 16.100
  [AVFoundation input device @ 0x7f8e2540ef20] AVFoundation video devices:
  [AVFoundation input device @ 0x7f8e2540ef20] [0] FaceTime HD camera (built-in)
  [AVFoundation input device @ 0x7f8e2540ef20] [1] Capture screen 0
  [AVFoundation input device @ 0x7f8e2540ef20] AVFoundation audio devices:
  [AVFoundation input device @ 0x7f8e2540ef20] [0] Blackmagic Audio
  [AVFoundation input device @ 0x7f8e2540ef20] [1] Built-in Microphone
  

  Then, you can specify and initialize your located screens in Sourcer API using its index shown:

  # initialize the sourcer with `0:` index desktop screen and probe it
  sourcer = Sourcer("0:", source_demuxer="avfoundation", verbose=True).probe_stream()
  

  If these steps doesn't work for you then reach us out on Gitter ➶ Community channel

  # initialize the sourcer with "0:" source and probe it
  sourcer = Sourcer("0:", source_demuxer="avfoundation", verbose=True).probe_stream()
  

• Virtual Sources: Valid filtergraph to use as input with lavfi (Libavfilter input virtual device) source that reads data from the open output pads of a libavfilter filtergraph. For example, for generating and probing Mandelbrot graph of 1280x720 frame size and 30 framerate using lavfi input virtual device, we can do as follows in Sourcer API:

  # initialize the sourcer with "mandelbrot" source of
  # `1280x720` frame size and `30` framerate and probe it
  sourcer = Sourcer(
      "mandelbrot=size=1280x720:rate=30",
      source_demuxer="lavfi",
      frame_format="bgr24",
  ).probe_stream()
  

source_demuxer¶

This parameter specifies the demuxer(-f) for the input source (such as dshow, v4l2, gdigrab etc.) to support Live Feed Devices, as well as lavfi (Libavfilter input virtual device) that reads data from the open output pads of a libavfilter filtergraph.

# initialize the sourcer with "0" index source and probe it
sourcer = Sourcer("0").probe_stream()

# initialize the sourcer with "0" index source and probe it
sourcer = Sourcer("0", source_demuxer="auto).probe_stream()

Data-Type: String

Default Value: Its default value is None.

Usage:

# initialize the sourcer with `dshow` demuxer and probe it
sourcer = Sourcer("foo.mp4", source_demuxer="dshow").probe_stream()

custom_ffmpeg¶

This parameter can be used to manually assigns the system file-path/directory where the custom or downloaded FFmpeg executable is located.

# # define suitable parameter to download at "C:/User/foo/foo1"
sourcer_params = {"-ffmpeg_download_path": "C:/User/foo/foo1"}

# initialize the sourcer
Sourcer("foo.mp4", verbose=True, **sourcer_params).probe_stream()

Data-Type: String

Default Value: Its default value is None.

Usage:

# If ffmpeg executables are located at "/foo/foo1/ffmpeg"
Sourcer("foo.mp4", custom_ffmpeg="/foo/foo1/ffmpeg").probe_stream()

verbose¶

This parameter enables verbose logs (if True), essential for debugging.

Data-Type: Boolean

Default Value: Its default value is False.

Usage:

# initialize the sourcer with verbose logs
Sourcer("foo.mp4", verbose=True).probe_stream()

sourcer_params¶

This dictionary parameter accepts all Exclusive Parameters formatted as its attributes:

Data-Type: Dictionary

Default Value: Its default value is {}.

Exclusive Parameters¶

Sourcer API supports few Exclusive Parameters to allow users to flexibly change its probing properties and handle some special FFmpeg parameters.

These parameters are discussed below:

• -ffprefixes (list): This attribute sets the special FFmpeg parameters that generally occurs at the very beginning (such as -re) before input (-i) source. The FFmpeg parameters defined with this attribute can repeated more than once and maintains its original order in the FFmpeg command. Its value can be of datatype list only and its usage is as follows:

  Turn on verbose parameter (verbose = True) to see the FFmpeg command that is being executed in Sourcer's pipeline. This helps you debug/address any issues and make adjustments accordingly.

  # define suitable parameter
  sourcer_params = {"-ffprefixes": ['-re']} # executes as `ffmpeg -re <rest of command>`
  

• -ffmpeg_download_path (string): sets the custom directory for downloading FFmpeg Static Binaries in Compression Mode, during the Auto-Installation on Windows Machines Only. If this parameter is not altered, then these binaries will auto-save to the default temporary directory (for e.g. C:/User/temp) on your windows machine. It can be used as follows:

  sourcer_params = {"-ffmpeg_download_path": "C:/User/foo/foo1"} # will be saved to "C:/User/foo/foo1"
  

• -force_validate_source (bool): forcefully passes validation test for given source which is required for some special cases with unusual input. It can be used as follows:

  sourcer_params = {"-force_validate_source": True} # will pass validation test forcefully