ans: Give buf_ans ownership of the AnsCoder

Change-Id: I509bbba0d84c1d378044e2c612dd48cd8f99848d

aom_dsp/buf_ans.h

@@ -39,8 +39,10 @@ struct buffered_ans_symbol {
 struct BufAnsCoder {
   struct aom_internal_error_info *error;
   struct buffered_ans_symbol *buf;
+  struct AnsCoder ans;
   int size;
   int offset;
+  int output_bytes;
 };
 
 void aom_buf_ans_alloc(struct BufAnsCoder *c,
@@ -50,8 +52,11 @@ void aom_buf_ans_free(struct BufAnsCoder *c);
 
 void aom_buf_ans_grow(struct BufAnsCoder *c);
 
-static INLINE void buf_ans_write_reset(struct BufAnsCoder *const c) {
+static INLINE void buf_ans_write_init(struct BufAnsCoder *const c,
+                                      uint8_t *const output_buffer) {
   c->offset = 0;
+  c->output_bytes = 0;
+  ans_write_init(&c->ans, output_buffer);
 }
 
 static INLINE void buf_uabs_write(struct BufAnsCoder *const c, uint8_t val,
@@ -78,20 +83,21 @@ static INLINE void buf_rans_write(struct BufAnsCoder *const c,
   ++c->offset;
 }
 
-static INLINE void buf_ans_flush(const struct BufAnsCoder *const c,
-                                 struct AnsCoder *ans) {
+static INLINE void buf_ans_flush(struct BufAnsCoder *const c) {
   int offset;
   for (offset = c->offset - 1; offset >= 0; --offset) {
     if (c->buf[offset].method == ANS_METHOD_RANS) {
       struct rans_sym sym;
       sym.prob = c->buf[offset].prob;
       sym.cum_prob = c->buf[offset].val_start;
-      rans_write(ans, &sym);
+      rans_write(&c->ans, &sym);
     } else {
-      uabs_write(ans, (uint8_t)c->buf[offset].val_start,
+      uabs_write(&c->ans, (uint8_t)c->buf[offset].val_start,
                  (AnsP8)c->buf[offset].prob);
     }
   }
+  c->offset = 0;
+  c->output_bytes += ans_write_end(&c->ans);
 }
 
 static INLINE void buf_uabs_write_bit(struct BufAnsCoder *c, int bit) {
@@ -106,6 +112,11 @@ static INLINE void buf_uabs_write_literal(struct BufAnsCoder *c, int literal,
   for (bit = bits - 1; bit >= 0; bit--)
     buf_uabs_write_bit(c, 1 & (literal >> bit));
 }
+
+static INLINE int buf_ans_write_end(struct BufAnsCoder *const c) {
+  assert(c->offset == 0);
+  return c->output_bytes;
+}
 #ifdef __cplusplus
 }  // extern "C"
 #endif  // __cplusplus

av1/encoder/bitstream.c

@@ -3464,7 +3464,7 @@ static uint32_t write_tiles(AV1_COMP *const cpi, uint8_t *const dst,
 #endif
   const AV1_COMMON *const cm = &cpi->common;
 #if CONFIG_ANS
-  struct AnsCoder token_ans;
+  struct BufAnsCoder *buf_ans = &cpi->buf_ans;
 #else
   aom_writer mode_bc;
 #endif  // CONFIG_ANS
@@ -3495,9 +3495,6 @@ static uint32_t write_tiles(AV1_COMP *const cpi, uint8_t *const dst,
 #if CONFIG_EXT_TILE
   const int have_tiles = tile_cols * tile_rows > 1;
 #endif  // CONFIG_EXT_TILE
-#if CONFIG_ANS
-  struct BufAnsCoder *buf_ans = &cpi->buf_ans;
-#endif  // CONFIG_ANS
 
   *max_tile_size = 0;
   *max_tile_col_size = 0;
@@ -3536,12 +3533,11 @@ static uint32_t write_tiles(AV1_COMP *const cpi, uint8_t *const dst,
       aom_stop_encode(&mode_bc);
       tile_size = mode_bc.pos;
 #else
-      buf_ans_write_reset(buf_ans);
+      buf_ans_write_init(buf_ans, buf->data + data_offset);
       write_modes(cpi, &tile_info, buf_ans, &tok, tok_end);
       assert(tok == tok_end);
-      ans_write_init(&token_ans, buf->data + data_offset);
-      buf_ans_flush(buf_ans, &token_ans);
-      tile_size = ans_write_end(&token_ans);
+      buf_ans_flush(buf_ans);
+      tile_size = buf_ans_write_end(buf_ans);
 #endif  // !CONFIG_ANS
 
       buf->size = tile_size;
@@ -3686,12 +3682,11 @@ static uint32_t write_tiles(AV1_COMP *const cpi, uint8_t *const dst,
       if (!is_last_tile) total_size += 4;
 
 #if CONFIG_ANS
-      buf_ans_write_reset(buf_ans);
+      buf_ans_write_init(buf_ans, dst + total_size);
       write_modes(cpi, &tile_info, buf_ans, &tok, tok_end);
       assert(tok == tok_end);
-      ans_write_init(&token_ans, dst + total_size);
-      buf_ans_flush(buf_ans, &token_ans);
-      tile_size = ans_write_end(&token_ans);
+      buf_ans_flush(buf_ans);
+      tile_size = buf_ans_write_end(buf_ans);
 #else
       aom_start_encode(&mode_bc, dst + total_size);
 #if CONFIG_PVQ
@@ -3703,10 +3698,10 @@ static uint32_t write_tiles(AV1_COMP *const cpi, uint8_t *const dst,
       assert(tok == tok_end);
       aom_stop_encode(&mode_bc);
       tile_size = mode_bc.pos;
-#endif
+#endif  // CONFIG_ANS
 #if CONFIG_PVQ
       cpi->td.mb.pvq_q = NULL;
-#endif  // !CONFIG_ANS
+#endif
 
       assert(tile_size > 0);
 
@@ -4132,10 +4127,9 @@ static uint32_t write_compressed_header(AV1_COMP *cpi, uint8_t *data) {
 #endif
 
 #if CONFIG_ANS
-  struct AnsCoder header_ans;
   int header_size;
   header_bc = &cpi->buf_ans;
-  buf_ans_write_reset(header_bc);
+  buf_ans_write_init(header_bc, data);
 #else
   aom_writer real_header_bc;
   header_bc = &real_header_bc;
@@ -4333,9 +4327,8 @@ static uint32_t write_compressed_header(AV1_COMP *cpi, uint8_t *data) {
 #endif
 #endif
 #if CONFIG_ANS
-  ans_write_init(&header_ans, data);
-  buf_ans_flush(header_bc, &header_ans);
-  header_size = ans_write_end(&header_ans);
+  buf_ans_flush(header_bc);
+  header_size = buf_ans_write_end(header_bc);
   assert(header_size <= 0xffff);
   return header_size;
 #else