BGE: add audio/video synchronization capability to VideoTexture

Add optional parameter to VideoTexture.Texture refresh() method
to specify timestamp (in seconds from start of movie) of the frame
to be loaded. This value is passed down to image source and for
VideoFFmpeg source, it is used instead of current time to load
the frame from the video file.

When combined with an audio actuator, it can be used to synchronize
the sound and the image: specify the same video file in the sound
actuator and use the KX_SoundActuator time attribute as timestamp
to refresh: the frame corresponding to the sound will be loaded:

GameLogic.video.refresh(True, soundAct.time)

1 files changed, 76 insertions, 15 deletions

diff --git a/source/gameengine/PyDoc/VideoTexture.py b/source/gameengine/PyDoc/VideoTexture.py
index cbcd28fb24c..8f8ad28e32e 100644
--- a/source/gameengine/PyDoc/VideoTexture.py
+++ b/source/gameengine/PyDoc/VideoTexture.py
@@ -1,33 +1,94 @@
 # $Id$
 """
-Documentation for the VideoTexture module.
+The VideoTexture module allows you to manipulate textures during the game. 
+Several sources for texture are possible: video files, image files, 
+video capture, memory buffer, camera render or a mix of that. 
+The video and image files can be loaded from the internet using an URL 
+instead of a file name. In addition, you can apply filters on the images
+before sending them to the GPU, allowing video effect: blue screen, 
+color band, gray, normal map. 
+VideoTexture uses FFmpeg to load images and videos. All the formats and codecs
+that FFmpeg supports are supported by VideoTexture, including but not limited to: 
+
+    * AVI
+    * Ogg
+    * Xvid
+    * Theora
+    * dv1394 camera
+    * video4linux capture card (this includes many webcams)
+    * videoForWindows capture card (this includes many webcams)
+    * JPG 
+
+The principle is simple: first you identify a texture on an existing object using 
+the L{materialID} function, then you create a new texture with dynamic content
+and swap the two textures in the GPU. 
+The GE is not aware of the substitution and continues to display the object as always, 
+except that you are now in control of the texture. At the end, the new texture is
+deleted and the old texture restored. 
 
 Example:
 	import VideoTexture
 	import GameLogic
 
+	contr = GameLogic.getCurrentController()
+	obj = contr.getOwner()
+	
+	# the creation of the texture must be done once: save the 
+	# texture object in an attribute of GameLogic module makes it persistent
+	if not hasattr(GameLogic, 'video'):
+	
+		# identify a static texture by name
+		matID = VideoTexture.materialID(obj, 'IMvideo.png')
+		
+		# create a dynamic texture that will replace the static texture
+		GameLogic.video = VideoTexture.Texture(obj, matID)
+		
+		# define a source of image for the texture, here a movie
+		movie = GameLogic.expandPath('//trailer_400p.ogg')
+		GameLogic.video.source = VideoTexture.VideoFFmpeg(movie)
+		GameLogic.video.source.scale = True
+		
+		# quick off the movie, but it wont play in the background
+		GameLogic.video.source.play()	
+		
+		# you need to call this function every frame to ensure update of the texture.
+		GameLogic.video.refresh(True)
+	
+
 """
 def getLastError():
 	"""
-	Does something
+	Returns the description of the last error that occured in a VideoTexture function.
 	
-	@rtype: 
+	@rtype: string
 	"""
 def imageToArray(image):
 	"""
-	Does something
+	Returns a string corresponding to the current image stored in a texture source object
 
-	@param image: Image ID
-	@type image: integer
-	@rtype: array
-	"""
-def materialID(material):
-	"""
-	Gets the ID of a material
-
-	@param material: the name of the material
-	@type material: string
-	@rtype: 
+	@param image: Image source object.
+	@type image: object of type L{VideoFFmpeg}, L{ImageFFmpeg}, L{ImageBuff}, L{ImageMix}, L{ImageRender}, L{ImageMirror} or L{ImageViewport}
+	@rtype: string representing the image, 4 bytes per pixel in the RGBA order, line per line, starting from the bottom of the image.
+	"""
+def materialID(object,name):
+	"""
+	Returns a numeric value that can be used in L{Texture} to create a dynamic texture.
+	The value corresponds to an internal material number that uses the texture identified
+	by name. name is a string representing a texture name with IM prefix if you want to
+	identify the texture directly. 	This method works for basic tex face and for material,
+	provided the material has a texture channel using that particular texture in first
+	position of the texture stack. 	name can also have MA prefix if you want to identify
+	the texture by material. In that case the material must have a texture channel in first
+	position.
+	If the object has no material that matches name, it generates a runtime error. Use try/catch to catch the exception.
+	
+	Ex: VideoTexture.materialID(obj, 'IMvideo.png')
+	
+	@param object: the game object that uses the texture you want to make dynamic
+	@type object: game object
+	@param name: name of the texture/material you want to make dynamic. 
+	@type name: string
+	@rtype: integer
 	"""
 def setLogFile():
 	"""