Use more descriptive long_names for Video4Linux input devices.

Originally committed as revision 16322 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavdevice/v4l.c

@@ -339,7 +339,7 @@ static int grab_read_close(AVFormatContext *s1)
 
 AVInputFormat v4l_demuxer = {
     "video4linux",
-    NULL_IF_CONFIG_SMALL("video grab"),
+    NULL_IF_CONFIG_SMALL("Video4Linux device grab"),
     sizeof(VideoData),
     NULL,
     grab_read_header,

libavdevice/v4l2.c

@@ -651,7 +651,7 @@ static int v4l2_read_close(AVFormatContext *s1)
 
 AVInputFormat v4l2_demuxer = {
     "video4linux2",
-    NULL_IF_CONFIG_SMALL("video grab"),
+    NULL_IF_CONFIG_SMALL("Video4Linux2 device grab"),
     sizeof(struct video_data),
     NULL,
     v4l2_read_header,