Changes between Version 1 and Version 2 of DirectShow

Timestamp:

12/18/2012 10:45:45 PM (5 months ago)

Author:

rogerdpack

Comment:

flesh out page

DirectShow

@@ -1 @@
-= DirectShow =
+= !DirectShow =
 
-Ffmpeg can take input from "directshow" devices on your windows computer.  These are typically video or audio devices that are attached.
+FFmpeg can take input from "directshow" devices on your windows computer.  These are typically video or audio devices that are attached.
 
 == 
@@ -28 +28 @@
 c:\> ffmpeg -f dshow -i video="Integrated Camera" out.mp4
 }}}
+
+You can also pass the device certain parameters that it needs, for instance a webcam might allow you to capture it in "1024x768" at up to max 5 fps, or allow you to capture at "640x480" at 30 fps.  You can enumerate the options like this:
+
+{{{c:\> ffmpeg -f dshow -list_options true -i video=<video device>}}}
+ex:
+
+{{{
+ffmpeg -f dshow -list_options true -i video="Integrated Camera"
+ffmpeg version N-45279-g6b86dd5 Copyright (c) 2000-2012 the FFmpeg developers
+  built on Oct 10 2012 17:30:47 with gcc 4.7.1 (GCC)
+  configuration:...
+  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 @ 01D4F3E0] DirectShow video device options
+[dshow @ 01D4F3E0]  Pin "Capture"
+[dshow @ 01D4F3E0]   pixel_format=yuyv422  min s=640x480 fps=15 max s=640x480 fps=30
+[dshow @ 01D4F3E0]   pixel_format=yuyv422  min s=1280x720 fps=7.5 max s=1280x720 fps=7.5
+[dshow @ 01D4F3E0]   vcodec=mjpeg  min s=640x480 fps=15 max s=640x480 fps=30
+[dshow @ 01D4F3E0]   vcodec=mjpeg  min s=1280x720 fps=15 max s=1280x720 fps=30
+video=Integrated Camera: Immediate exit requested
+}}}
+
+You can see in this particular instance that it can either stream it to you in a "raw pixel_format" (yuyv422 in this case), or as an mjpeg stream.
+
+You can specify the type (mjpeg) and size (1280x720) and frame rate to tell the device to give you (15 fps), like this:
+
+{{{ ffmpeg -f dshow -s 1280x720 -r 15 -vcodec mjpeg -i video="Integrated Camera" out.avi }}}
+
+Sometimes it helps to specify "-vcodec copy" to save on cpu to re-encode, if you can receive the data in some type of pre-encoded format, like mjpeg in this instance.
+
+Also this note that "The input string is in the format video=<video device name>:audio=<audio device name>. It is possible to have two separate inputs (like -f dshow -i audio=foo -f dshow -i video=bar) but my limited tests had shown a better synchronism when both were used in the same input."
+
+== !AviSynth ==
+
+FFmpeg can also take !DirectShow input by creating an avisynth file (.avs file) that itself gets input from a graphedit file, which graphedit file exposes a pin of your capture source or any filter really, ex ("yo.avs"):
+
+{{{DirectShowSource?("push2.GRF", fps=35, audio=False, framecount=1000000)}}}