Add API for writing trees using a CDF.

Added aom_write_tree_cdf() and aom_read_tree_cdf() function calls to
 bitwriter.h and bitreader.h respectively.
These calls take a multisymbol CDF and an index and directly encode the
 symbol using the enabled entropy coder.
Currently only the daala entropy encoder supports this (enabled with
 --enable-daala_ec) and a compile error is thrown otherwise.

Change-Id: I2fa1e87af4352c94384e0cfdbfd170ac99cf3705

aom_dsp/bitreader.h

@@ -24,6 +24,7 @@
 #include "aom_dsp/dkboolreader.h"
 #endif
 #include "aom_dsp/prob.h"
+#include "av1/common/odintrin.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -101,6 +102,19 @@ static INLINE int aom_read_tree(aom_reader *r, const aom_tree_index *tree,
 #endif
 }
 
+static INLINE int aom_read_tree_cdf(aom_reader *r, const uint16_t *cdf,
+                                    int nsymbs) {
+#if CONFIG_DAALA_EC
+  return daala_read_tree_cdf(r, cdf, nsymbs);
+#else
+  (void)r;
+  (void)cdf;
+  (void)nsymbs;
+  assert(0 && "Unsupported bitreader operation");
+  return -1;
+#endif
+}
+
 #ifdef __cplusplus
 }  // extern "C"
 #endif

aom_dsp/bitwriter.h

@@ -12,6 +12,7 @@
 #ifndef AOM_DSP_BITWRITER_H_
 #define AOM_DSP_BITWRITER_H_
 
+#include <assert.h>
 #include "./aom_config.h"
 #if CONFIG_DAALA_EC
 #include "aom_dsp/daalaboolwriter.h"
@@ -84,6 +85,19 @@ static INLINE void aom_write_tree(aom_writer *w, const aom_tree_index *tree,
 #endif
 }
 
+static INLINE void aom_write_tree_cdf(aom_writer *w, int symb,
+                                      const uint16_t *cdf, int nsymbs) {
+#if CONFIG_DAALA_EC
+  daala_write_tree_cdf(w, symb, cdf, nsymbs);
+#else
+  (void)w;
+  (void)symb;
+  (void)cdf;
+  (void)nsymbs;
+  assert(0 && "Unsupported bitwriter operation");
+#endif
+}
+
 #ifdef __cplusplus
 }  // extern "C"
 #endif

aom_dsp/daalaboolreader.h

@@ -66,6 +66,11 @@ static INLINE int daala_read_tree_bits(daala_reader *r,
   return -i;
 }
 
+static INLINE int daala_read_tree_cdf(daala_reader *r, const uint16_t *cdf,
+                                      int nsymbs) {
+  return od_ec_decode_cdf_q15(&r->ec, cdf, nsymbs, "aom");
+}
+
 #ifdef __cplusplus
 }  // extern "C"
 #endif

aom_dsp/daalaboolwriter.h

@@ -78,6 +78,11 @@ static INLINE void daala_write_tree_bits(daala_writer *w,
   } while (len);
 }
 
+static INLINE void daala_write_tree_cdf(daala_writer *w, int symb,
+                                        const uint16_t *cdf, int nsymbs) {
+  od_ec_encode_cdf_q15(&w->ec, symb, cdf, nsymbs);
+}
+
 #ifdef __cplusplus
 }  // extern "C"
 #endif