* introducing new public interface in imgconvert.c

+ avcodec_get_pix_fmt
         converts textual representation of pixel format into
	 the actual id. Complements avcodec_get_pix_fmt_name.
       + avpicture_layout
         serializes given picture into a flat array.
	 Complements avpicture_fill.

   * adding a new option -pix_fmt to the ffmpeg, in order to control
     pixel format for the codecs that do support it, like rawvideo,
     for example.

   * reducing complexity of the rawvideo codec by splitting it in two
     and making it more reliable via hooking up to the avpicture_layout.
     Plus adding new FourCC as described here: http://www.fourcc.org

   * A tiny fix for avienc.c that makes avih and video strf consistent
     regarding codec FourCC.

Originally committed as revision 1842 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/allcodecs.c

@@ -65,7 +65,8 @@ void avcodec_register_all(void)
     register_avcodec(&mjpeg_encoder);
     register_avcodec(&huffyuv_encoder);
 #endif /* CONFIG_ENCODERS */
-    register_avcodec(&rawvideo_codec);
+    register_avcodec(&rawvideo_encoder);
+    register_avcodec(&rawvideo_decoder);
 
     /* decoders */
 #ifdef CONFIG_DECODERS