1 files changed, 82 insertions, 0 deletions
diff --git a/src/video_dec/libvdpau/bits_reader.h b/src/video_dec/libvdpau/bits_reader.h
new file mode 100644
index 000000000..db7cdfc7e
--- /dev/null
+++ b/src/video_dec/libvdpau/bits_reader.h
@@ -0,0 +1,82 @@
+#include <sys/types.h>
+
+
+
+typedef struct {
+  uint8_t *buffer, *start;
+  int      offbits, length, oflow;
+} bits_reader_t;
+
+
+
+static void bits_reader_set( bits_reader_t *br, uint8_t *buf, int len )
+{
+  br->buffer = br->start = buf;
+  br->offbits = 0;
+  br->length = len;
+  br->oflow = 0;
+}
+
+
+
+static uint32_t read_bits( bits_reader_t *br, int nbits )
+{
+  int i, nbytes;
+  uint32_t ret = 0;
+  uint8_t *buf;
+
+  buf = br->buffer;
+  nbytes = (br->offbits + nbits)/8;
+  if ( ((br->offbits + nbits) %8 ) > 0 )
+    nbytes++;
+  if ( (buf + nbytes) > (br->start + br->length) ) {
+    br->oflow = 1;
+    return 0;
+  }
+  for ( i=0; i<nbytes; i++ )
+    ret += buf[i]<<((nbytes-i-1)*8);
+  i = (4-nbytes)*8+br->offbits;
+  ret = ((ret<<i)>>i)>>((nbytes*8)-nbits-br->offbits);
+
+  br->offbits += nbits;
+  br->buffer += br->offbits / 8;
+  br->offbits %= 8;
+
+  return ret;
+}
+
+
+
+static void skip_bits( bits_reader_t *br, int nbits )
+{
+  br->offbits += nbits;
+  br->buffer += br->offbits / 8;
+  br->offbits %= 8;
+  if ( br->buffer > (br->start + br->length) ) {
+    br->oflow = 1;
+  }
+}
+
+
+
+static uint32_t get_bits( bits_reader_t *br, int nbits )
+{
+  int i, nbytes;
+  uint32_t ret = 0;
+  uint8_t *buf;
+
+  buf = br->buffer;
+  nbytes = (br->offbits + nbits)/8;
+  if ( ((br->offbits + nbits) %8 ) > 0 )
+    nbytes++;
+  if ( (buf + nbytes) > (br->start + br->length) ) {
+    br->oflow = 1;
+    return 0;
+  }
+  for ( i=0; i<nbytes; i++ )
+    ret += buf[i]<<((nbytes-i-1)*8);
+  i = (4-nbytes)*8+br->offbits;
+  ret = ((ret<<i)>>i)>>((nbytes*8)-nbits-br->offbits);
+
+  return ret;
+}