Support code show_existing_frame in bit-stream header

Allow the bit-stream writer to support potential use of
show_existing_frame. At this point, cm->show_existing_frame is
always 0.

Change-Id: I64fed1d72db6d4902d56774854ce24fb7a082e0c

diff --git a/vp9/encoder/vp9_bitstream.c b/vp9/encoder/vp9_bitstream.c
index 0c6681c2b689ce3ae452b1eb5f971a822e5e2af7..9f39c189b1d5e2fb5b7ef1221811b8209991bce9 100644 (file)
--- a/vp9/encoder/vp9_bitstream.c
+++ b/vp9/encoder/vp9_bitstream.c
@@ -1192,7 +1192,13 @@ static void write_uncompressed_header(VP9_COMP *cpi,
 
   write_profile(cm->profile, wb);
 
-  vpx_wb_write_bit(wb, 0);  // show_existing_frame
+  // If to use show existing frame.
+  vpx_wb_write_bit(wb, cm->show_existing_frame);
+  if (cm->show_existing_frame) {
+    vpx_wb_write_literal(wb, cpi->alt_fb_idx, 3);
+    return;
+  }
+
   vpx_wb_write_bit(wb, cm->frame_type);
   vpx_wb_write_bit(wb, cm->show_frame);
   vpx_wb_write_bit(wb, cm->error_resilient_mode);