basic type mechanism working

1 files changed, 30 insertions, 3 deletions

diff --git a/ffmpeg/libavcodec/cabac_functions.h b/ffmpeg/libavcodec/cabac_functions.h
index ee70fcf..7e22064 100644
--- a/ffmpeg/libavcodec/cabac_functions.h
+++ b/ffmpeg/libavcodec/cabac_functions.h
@@ -49,7 +49,10 @@ static void refill(CABACContext *c){
         c->low+= c->bytestream[0]<<1;
 #endif
     c->low -= CABAC_MASK;
-    c->bytestream += CABAC_BITS / 8;
+#if !UNCHECKED_BITSTREAM_READER
+    if (c->bytestream < c->bytestream_end)
+#endif
+        c->bytestream += CABAC_BITS / 8;
 }
 
 static inline void renorm_cabac_decoder_once(CABACContext *c){
@@ -76,7 +79,10 @@ static void refill2(CABACContext *c){
 #endif
 
     c->low += x<<i;
-    c->bytestream += CABAC_BITS/8;
+#if !UNCHECKED_BITSTREAM_READER
+    if (c->bytestream < c->bytestream_end)
+#endif
+        c->bytestream += CABAC_BITS/8;
 }
 
 static av_always_inline int get_cabac_inline(CABACContext *c, uint8_t * const state){
@@ -111,6 +117,7 @@ static int av_unused get_cabac(CABACContext *c, uint8_t * const state){
     return get_cabac_inline(c,state);
 }
 
+#ifndef get_cabac_bypass
 static int av_unused get_cabac_bypass(CABACContext *c){
     int range;
     c->low += c->low;
@@ -126,7 +133,7 @@ static int av_unused get_cabac_bypass(CABACContext *c){
         return 1;
     }
 }
-
+#endif
 
 #ifndef get_cabac_bypass_sign
 static av_always_inline int get_cabac_bypass_sign(CABACContext *c, int val){
@@ -159,4 +166,24 @@ static int av_unused get_cabac_terminate(CABACContext *c){
     }
 }
 
+/**
+ * Skip @p n bytes and reset the decoder.
+ * @return the address of the first skipped byte or NULL if there's less than @p n bytes left
+ */
+static av_unused const uint8_t* skip_bytes(CABACContext *c, int n) {
+    const uint8_t *ptr = c->bytestream;
+
+    if (c->low & 0x1)
+        ptr--;
+#if CABAC_BITS == 16
+    if (c->low & 0x1FF)
+        ptr--;
+#endif
+    if ((int) (c->bytestream_end - ptr) < n)
+        return NULL;
+    ff_init_cabac_decoder(c, ptr + n, c->bytestream_end - ptr - n);
+
+    return ptr;
+}
+
 #endif /* AVCODEC_CABAC_FUNCTIONS_H */