Adds ability to measure with a higher precision the number of bits
read per symbol.
Change-Id: I218abaa5172b769b66dba45050381c0212602668
diff --git a/test/boolcoder_test.cc b/test/boolcoder_test.cc
index de9b6e4..f1bad33 100644
--- a/test/boolcoder_test.cc
+++ b/test/boolcoder_test.cc
@@ -88,3 +88,54 @@
}
}
}
+
+#if CONFIG_DAALA_EC
+#define FRAC_DIFF_TOTAL_ERROR 0.07
+#else
+#define FRAC_DIFF_TOTAL_ERROR 0.2
+#endif
+
+TEST(AV1, TestTell) {
+ const int kBufferSize = 10000;
+ aom_writer bw;
+ uint8_t bw_buffer[kBufferSize];
+ const int kSymbols = 1024;
+ // Coders are noisier at low probabilities, so we start at p = 4.
+ for (int p = 4; p <= 256; p++) {
+ double probability = p / 256.;
+ aom_start_encode(&bw, bw_buffer);
+ for (int i = 0; i < kSymbols; i++) {
+ aom_write(&bw, 0, p);
+ }
+ aom_stop_encode(&bw);
+ aom_reader br;
+ aom_reader_init(&br, bw_buffer, kBufferSize, NULL, NULL);
+ ptrdiff_t last_tell = aom_reader_tell(&br);
+ ptrdiff_t last_tell_frac = aom_reader_tell_frac(&br);
+ double frac_diff_total = 0;
+ GTEST_ASSERT_GE(aom_reader_tell(&br), 0);
+ GTEST_ASSERT_LE(aom_reader_tell(&br), 1);
+ for (int i = 0; i < kSymbols; i++) {
+ aom_read(&br, p);
+ ptrdiff_t tell = aom_reader_tell(&br);
+ ptrdiff_t tell_frac = aom_reader_tell_frac(&br);
+ GTEST_ASSERT_GE(tell, last_tell) << "tell: " << tell
+ << ", last_tell: " << last_tell;
+ GTEST_ASSERT_GE(tell_frac, last_tell_frac)
+ << "tell_frac: " << tell_frac
+ << ", last_tell_frac: " << last_tell_frac;
+ // Frac tell should round up to tell.
+ GTEST_ASSERT_EQ(tell, (tell_frac + 7) >> 3);
+ last_tell = tell;
+ frac_diff_total +=
+ fabs(((tell_frac - last_tell_frac) / 8.0) + log2(probability));
+ last_tell_frac = tell_frac;
+ }
+ const int expected = (int)(-kSymbols * log2(probability));
+ // Last tell should be close to the expected value.
+ GTEST_ASSERT_LE(last_tell - expected, 20) << " last_tell: " << last_tell;
+ // The average frac_diff error should be pretty small.
+ GTEST_ASSERT_LE(frac_diff_total / kSymbols, FRAC_DIFF_TOTAL_ERROR)
+ << " frac_diff_total: " << frac_diff_total;
+ }
+}
