Switch to bits_reader.

1 files changed, 36 insertions, 0 deletions

diff --git a/src/libvdpau/bits_reader.h b/src/libvdpau/bits_reader.h
new file mode 100644
index 000000000..9563c9d3b
--- /dev/null
+++ b/src/libvdpau/bits_reader.h
@@ -0,0 +1,36 @@
+#include <sys/types.h>
+
+
+
+typedef struct {
+  uint8_t *buffer;
+  int      offbits;
+} bits_reader_t;
+
+static void bits_reader_set( bits_reader_t *br, uint8_t *buf )
+{
+  br->buffer = buf;
+  br->offbits = 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++;
+  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;
+}