Bit accounting.
This patch adds bit account infrastructure to the bit reader API.
When configured with --enable-accounting, every bit reader API
function records the number of bits necessary to decoding a symbol.
Accounting symbol entries are collected in global accounting data
structure, that can be used to understand exactly where bits are
spent (http://aomanalyzer.org). The data structure is cleared and
reused each frame to reduce memory usage. When configured without
--enable-accounting, bit accounting does not incur any runtime
overhead.
All aom_read_xxx functions now have an additional string parameter
that specifies the symbol name. By default, the ACCT_STR macro is
used (which expands to __func__). For more precise accounting,
these should be replaced with more descriptive names.
Change-Id: Ia2e1343cb842c9391b12b77272587dfbe307a56d
diff --git a/test/accounting_test.cc b/test/accounting_test.cc
new file mode 100644
index 0000000..122f9b8
--- /dev/null
+++ b/test/accounting_test.cc
@@ -0,0 +1,75 @@
+/*
+ * 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 <math.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "third_party/googletest/src/include/gtest/gtest.h"
+
+#include "test/acm_random.h"
+#include "aom/aom_integer.h"
+#include "aom_dsp/bitreader.h"
+#include "aom_dsp/bitwriter.h"
+
+using libaom_test::ACMRandom;
+
+TEST(AV1, TestAccounting) {
+ const int kBufferSize = 10000;
+ const int kSymbols = 1024;
+ aom_writer bw;
+ uint8_t bw_buffer[kBufferSize];
+ aom_start_encode(&bw, bw_buffer);
+ for (int i = 0; i < kSymbols; i++) {
+ aom_write(&bw, 0, 32);
+ aom_write(&bw, 0, 32);
+ aom_write(&bw, 0, 32);
+ }
+ aom_stop_encode(&bw);
+ aom_reader br;
+ aom_reader_init(&br, bw_buffer, kBufferSize, NULL, NULL);
+
+ Accounting accounting;
+ aom_accounting_init(&accounting);
+ br.accounting = &accounting;
+ for (int i = 0; i < kSymbols; i++) {
+ aom_read(&br, 32, "A");
+ }
+ // Consecutive symbols that are the same are coalesced.
+ GTEST_ASSERT_EQ(accounting.syms.num_syms, 1);
+ GTEST_ASSERT_EQ(accounting.syms.syms[0].samples, (unsigned int)kSymbols);
+
+ aom_accounting_reset(&accounting);
+ GTEST_ASSERT_EQ(accounting.syms.num_syms, 0);
+
+ // Should record 2 * kSymbols accounting symbols.
+ aom_reader_init(&br, bw_buffer, kBufferSize, NULL, NULL);
+ br.accounting = &accounting;
+ for (int i = 0; i < kSymbols; i++) {
+ aom_read(&br, 32, "A");
+ aom_read(&br, 32, "B");
+ aom_read(&br, 32, "B");
+ }
+ GTEST_ASSERT_EQ(accounting.syms.num_syms, kSymbols * 2);
+ uint32_t tell_frac = aom_reader_tell_frac(&br);
+ for (int i = 0; i < accounting.syms.num_syms; i++) {
+ tell_frac -= accounting.syms.syms[i].bits;
+ }
+ GTEST_ASSERT_EQ(tell_frac, 0U);
+
+ GTEST_ASSERT_EQ(aom_accounting_dictionary_lookup(&accounting, "A"),
+ aom_accounting_dictionary_lookup(&accounting, "A"));
+
+ // Check for collisions. The current aom_accounting_hash function returns
+ // the same hash code for AB and BA.
+ GTEST_ASSERT_NE(aom_accounting_dictionary_lookup(&accounting, "AB"),
+ aom_accounting_dictionary_lookup(&accounting, "BA"));
+}
