Video sink GRC block documentation

Author: courtarro

gr-video-sdl/grc/video_sdl_sink.xml

@@ -4,21 +4,21 @@
     <key>video_sdl_sink</key>
     <import>from gnuradio import video_sdl</import>
     <make>video_sdl.sink_$(type.fcn)($fps, $width, $height, 0, $display_width, $display_height)</make>
-	<param>
-		<name>Input Type</name>
-		<key>type</key>
-		<type>enum</type>
-		<option>
-			<name>Byte</name>
-			<key>byte</key>
-			<opt>fcn:uc</opt>
-		</option>
-		<option>
-			<name>Short</name>
-			<key>short</key>
-			<opt>fcn:s</opt>
-		</option>
-	</param>
+    <param>
+        <name>Input Type</name>
+        <key>type</key>
+        <type>enum</type>
+        <option>
+            <name>Byte</name>
+            <key>byte</key>
+            <opt>fcn:uc</opt>
+        </option>
+        <option>
+            <name>Short</name>
+            <key>short</key>
+            <opt>fcn:s</opt>
+        </option>
+    </param>
     <param>
         <name>Input Width</name>
         <key>width</key>
@@ -49,27 +49,38 @@
         <value>0</value>
         <type>float</type>
     </param>
-	<param>
-		<name>Channels</name>
-		<key>num_channels</key>
-		<type>enum</type>
-		<option>
-			<name>1 (Grayscale)</name>
-			<key>1</key>
-		</option>
-		<option>
-			<name>2 (Y, alternating pixels U and V)</name>
-			<key>2</key>
-		</option>
-		<option>
-			<name>3 (YUV)</name>
-			<key>3</key>
-		</option>
-	</param>
+    <param>
+        <name>Channels</name>
+        <key>num_channels</key>
+        <type>enum</type>
+        <option>
+            <name>1 (Grayscale)</name>
+            <key>1</key>
+        </option>
+        <option>
+            <name>2 (Y, alternating pixels U and V)</name>
+            <key>2</key>
+        </option>
+        <option>
+            <name>3 (YUV)</name>
+            <key>3</key>
+        </option>
+    </param>
     <sink>
         <name>in</name>
         <type>$type</type>
         <vlen>1</vlen>
         <nports>$num_channels</nports>
     </sink>
+    <doc>
+Provides a rudimentary on-screen video display using libsdl.
+
+A framerate of zero means video will be displayed as quickly as possible.
+
+In 1-channel mode, input data is assumed to be grayscale, with each input item mapping to a single pixel.
+
+In 2-channel mode, the first channel is Y for every pixel while the second channel alternates between pixels values for U and V.
+
+In 3-channel mode, input channels are assumed to be matching triples of YUV values, one byte per pixel, per channel.
+    </doc>
 </block>