mjpegb support (need more samples)

Originally committed as revision 1258 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/allcodecs.c

@@ -73,6 +73,7 @@ void avcodec_register_all(void)
     register_avcodec(&dvvideo_decoder);
     //    register_avcodec(&dvaudio_decoder);
     register_avcodec(&mjpeg_decoder);
+    register_avcodec(&mjpegb_decoder);
     register_avcodec(&mp2_decoder);
     register_avcodec(&mp3_decoder);
     register_avcodec(&wmav1_decoder);