[Mesa-dev] [PATCH v2] vl/rbsp: add a check for emulation prevention three byte

[Leo Liu]

This is the case when the "00 00 03" is very close to the beginning of
nal unit header

v2: move the check to rbsp init

Signed-off-by: Leo Liu <leo.liu at amd.com>
---
 src/gallium/auxiliary/vl/vl_rbsp.h | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/gallium/auxiliary/vl/vl_rbsp.h b/src/gallium/auxiliary/vl/vl_rbsp.h
index 7867238..c175e23 100644
--- a/src/gallium/auxiliary/vl/vl_rbsp.h
+++ b/src/gallium/auxiliary/vl/vl_rbsp.h
@@ -61,7 +61,18 @@ static inline void vl_rbsp_init(struct vl_rbsp *rbsp, struct vl_vlc *nal, unsign
    while (vl_vlc_search_byte(nal, num_bits, 0x00)) {
       if (vl_vlc_peekbits(nal, 24) == 0x000001 ||
           vl_vlc_peekbits(nal, 32) == 0x00000001) {
+         unsigned valid;
+         int i;
+
          vl_vlc_limit(&rbsp->nal, bits_left - vl_vlc_bits_left(nal));
+         valid = vl_vlc_valid_bits(&rbsp->nal);
+         /* search for the emulation prevention three byte */
+         for (i = 24; i <= valid; i += 8) {
+            if ((vl_vlc_peekbits(&rbsp->nal, i) & 0xffffff) == 0x3) {
+               vl_vlc_removebits(&rbsp->nal, i - 8, 8);
+               i += 8;
+            }
+         }
          return;
       }
       vl_vlc_eatbits(nal, 8);
-- 
2.7.4