vp8: make gf_group_bits 64-bit

avoids signed integer overflow; matches kf_group_bits

Change-Id: I193145cdc4fa53e70fba0a1731a03eb1a574931d

vp8/encoder/firstpass.c

@@ -2131,8 +2131,10 @@ static void define_gf_group(VP8_COMP *cpi, FIRSTPASS_STATS *this_frame)
     /* Clip cpi->twopass.gf_group_bits based on user supplied data rate
      * variability limit (cpi->oxcf.two_pass_vbrmax_section)
      */
-    if (cpi->twopass.gf_group_bits > max_bits * cpi->baseline_gf_interval)
-        cpi->twopass.gf_group_bits = max_bits * cpi->baseline_gf_interval;
+    if (cpi->twopass.gf_group_bits >
+        (int64_t)max_bits * cpi->baseline_gf_interval)
+        cpi->twopass.gf_group_bits =
+            (int64_t)max_bits * cpi->baseline_gf_interval;
 
     /* Reset the file position */
     reset_fpf_position(cpi, start_pos);

vp8/encoder/onyx_int.h

@@ -587,7 +587,7 @@ typedef struct VP8_COMP
         /* Error score of frames still to be coded in kf group */
         int64_t kf_group_error_left;
         /* Projected Bits available for a group including 1 GF or ARF */
-        int gf_group_bits;
+        int64_t gf_group_bits;
         /* Bits for the golden frame or ARF */
         int gf_bits;
         int alt_extra_bits;

vp9/encoder/vp9_firstpass.c

@@ -1707,8 +1707,9 @@ static void define_gf_group(VP9_COMP *cpi, FIRSTPASS_STATS *this_frame) {
 
   // Clip cpi->twopass.gf_group_bits based on user supplied data rate
   // variability limit (cpi->oxcf.two_pass_vbrmax_section)
-  if (cpi->twopass.gf_group_bits > max_bits * cpi->baseline_gf_interval)
-    cpi->twopass.gf_group_bits = max_bits * cpi->baseline_gf_interval;
+  if (cpi->twopass.gf_group_bits >
+      (int64_t)max_bits * cpi->baseline_gf_interval)
+    cpi->twopass.gf_group_bits = (int64_t)max_bits * cpi->baseline_gf_interval;
 
   // Reset the file position
   reset_fpf_position(cpi, start_pos);