Demuxer dshow [DirectShow capture]:
dshow indev AVOptions:
-video_size        <image_size> .D.... set video size given a string such as 640x480 or hd720.
-pixel_format      <pix_fmt>    .D.... set video pixel format
-framerate         <string>     .D.... set video frame rate
-sample_rate       <int>        .D.... set audio sample rate (from 0 to INT_MAX)
-sample_size       <int>        .D.... set audio sample size (from 0 to 16)
-channels          <int>        .D.... set number of audio channels, such as 1 or 2 (from 0 to INT_MAX)
-list_devices      <int>        .D.... list available devices (from 0 to 1)
   true                         .D.... 
   false                        .D.... 
-list_options      <int>        .D.... list available options for specified device (from 0 to 1)
   true                         .D.... 
   false                        .D.... 
-video_device_number <int>        .D.... set video device number for devices with same name (starts at 0) (from 0 to INT_MAX)
-audio_device_number <int>        .D.... set audio device number for devices with same name (starts at 0) (from 0 to INT_MAX)
-audio_buffer_size <int>        .D.... set audio device buffer latency size in milliseconds (default is the device's default) (from 0 to INT_MAX)

