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-rw-r--r--media/libaom/src/aom_dsp/buf_ans.c70
1 files changed, 70 insertions, 0 deletions
diff --git a/media/libaom/src/aom_dsp/buf_ans.c b/media/libaom/src/aom_dsp/buf_ans.c
new file mode 100644
index 000000000..f7703dffc
--- /dev/null
+++ b/media/libaom/src/aom_dsp/buf_ans.c
@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+
+#include <string.h>
+
+#include "aom_dsp/buf_ans.h"
+#include "aom_mem/aom_mem.h"
+#include "aom/internal/aom_codec_internal.h"
+
+void aom_buf_ans_alloc(struct BufAnsCoder *c,
+ struct aom_internal_error_info *error) {
+ c->error = error;
+ assert(c->size > 1);
+ AOM_CHECK_MEM_ERROR(error, c->buf, aom_malloc(c->size * sizeof(*c->buf)));
+ // Initialize to overfull to trigger the assert in write.
+ c->offset = c->size + 1;
+}
+
+void aom_buf_ans_free(struct BufAnsCoder *c) {
+ aom_free(c->buf);
+ c->buf = NULL;
+ c->size = 0;
+}
+
+#if !ANS_MAX_SYMBOLS
+void aom_buf_ans_grow(struct BufAnsCoder *c) {
+ struct buffered_ans_symbol *new_buf = NULL;
+ int new_size = c->size * 2;
+ AOM_CHECK_MEM_ERROR(c->error, new_buf,
+ aom_malloc(new_size * sizeof(*new_buf)));
+ memcpy(new_buf, c->buf, c->size * sizeof(*c->buf));
+ aom_free(c->buf);
+ c->buf = new_buf;
+ c->size = new_size;
+}
+#endif
+
+void aom_buf_ans_flush(struct BufAnsCoder *const c) {
+ int offset;
+#if ANS_MAX_SYMBOLS
+ if (c->offset == 0) return;
+#endif
+ assert(c->offset > 0);
+ offset = c->offset - 1;
+ // Code the first symbol such that it brings the state to the smallest normal
+ // state from an initial state that would have been a subnormal/refill state.
+ if (c->buf[offset].method == ANS_METHOD_RANS) {
+ c->ans.state += c->buf[offset].val_start;
+ } else {
+ c->ans.state += c->buf[offset].val_start ? c->buf[offset].prob : 0;
+ }
+ for (offset = offset - 1; offset >= 0; --offset) {
+ if (c->buf[offset].method == ANS_METHOD_RANS) {
+ rans_write(&c->ans, c->buf[offset].val_start, c->buf[offset].prob);
+ } else {
+ rabs_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);
+}