BITMAP_ID         280 libavformat/swfenc.c         avio_wl16(pb, BITMAP_ID); /* bitmap ID */
BITMAP_ID         403 libavformat/swfenc.c             avio_wl16(pb, BITMAP_ID);
BITMAP_ID         409 libavformat/swfenc.c         avio_wl16(pb, BITMAP_ID); /* ID of the image */