[x264-devel] commit: Fix 2 bugs with slice-max-size (Jason Garrett-Glaser )

[git at videolan.org]

x264 | branch: master | Jason Garrett-Glaser <darkshikari at gmail.com> | Tue Aug 17 14:38:41 2010 -0700| [31e458faf03c8c673c1d7e8c9f6dd40c193d211f] | committer: Jason Garrett-Glaser 

Fix 2 bugs with slice-max-size
Macroblock re-encoding didn't restore mv/tex bit counters (slightly inaccurate 2-pass).
Bitstream buffer check didn't work correctly (insanely large frames could break encoding).

> http://git.videolan.org/gitweb.cgi/x264.git/?a=commit;h=31e458faf03c8c673c1d7e8c9f6dd40c193d211f
---

 encoder/encoder.c |   13 ++++++++++---
 1 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/encoder/encoder.c b/encoder/encoder.c
index 6fd8838..52b6fb5 100644
--- a/encoder/encoder.c
+++ b/encoder/encoder.c
@@ -1827,6 +1827,8 @@ static int x264_slice_write( x264_t *h )
     bs_t bs_bak;
     x264_cabac_t cabac_bak;
     uint8_t cabac_prevbyte_bak = 0; /* Shut up GCC. */
+    int mv_bits_bak = 0;
+    int tex_bits_bak = 0;
     /* Assume no more than 3 bytes of NALU escaping.
      * NALUs other than the first use a 3-byte startcode. */
     int overhead_guess = (NALU_OVERHEAD - (h->param.b_annexb && h->out.i_nal)) + 3;
@@ -1873,8 +1875,14 @@ static int x264_slice_write( x264_t *h )
     while( (mb_xy = i_mb_x + i_mb_y * h->mb.i_mb_width) <= h->sh.i_last_mb )
     {
         int mb_spos = bs_pos(&h->out.bs) + x264_cabac_pos(&h->cabac);
+
+        if( x264_bitstream_check_buffer( h ) )
+            return -1;
+
         if( h->param.i_slice_max_size > 0 )
         {
+            mv_bits_bak = h->stat.frame.i_mv_bits;
+            tex_bits_bak = h->stat.frame.i_tex_bits;
             /* We don't need the contexts because flushing the CABAC encoder has no context
              * dependency and macroblocks are only re-encoded in the case where a slice is
              * ended (and thus the content of all contexts are thrown away). */
@@ -1903,9 +1911,6 @@ static int x264_slice_write( x264_t *h )
         /* encode this macroblock -> be careful it can change the mb type to P_SKIP if needed */
         x264_macroblock_encode( h );
 
-        if( x264_bitstream_check_buffer( h ) )
-            return -1;
-
         if( h->param.b_cabac )
         {
             if( mb_xy > h->sh.i_first_mb && !(h->sh.b_mbaff && (i_mb_y&1)) )
@@ -1943,6 +1948,8 @@ static int x264_slice_write( x264_t *h )
         {
             if( mb_xy != h->sh.i_first_mb )
             {
+                h->stat.frame.i_mv_bits = mv_bits_bak;
+                h->stat.frame.i_tex_bits = tex_bits_bak;
                 if( h->param.b_cabac )
                 {
                     memcpy( &h->cabac, &cabac_bak, offsetof(x264_cabac_t, f8_bits_encoded) );