Add coding path sync test

The goal is:
1) to provide a tool allowing to diagnose
and fix mismatches between LBD/HBD coding paths.

2) once all mismatches are fixed, this test
should be enabled so new ones can't be introduced.

Change-Id: I71c1db4c2cb142e9e3a7a4b02dd0d61f35b77178

test/coding_path_sync.cc

+/*
+ * 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 <vector>
+#include "third_party/googletest/src/googletest/include/gtest/gtest.h"
+#include "test/acm_random.h"
+
+#include "./aom_config.h"
+
+#if CONFIG_AV1_ENCODER && CONFIG_AV1_DECODER
+
+#include "aom_ports/mem.h"  // ROUND_POWER_OF_TWO
+#include "aom/aomcx.h"
+#include "aom/aomdx.h"
+#include "aom/aom_encoder.h"
+#include "aom/aom_decoder.h"
+
+using libaom_test::ACMRandom;
+namespace {
+
+struct CompressedSource {
+  explicit CompressedSource(int seed) : rnd_(seed) {
+    frame_count_ = 0;
+    aom_codec_iface_t *algo = &aom_codec_av1_cx_algo;
+
+    aom_codec_enc_cfg_t cfg;
+    aom_codec_enc_config_default(algo, &cfg, 0);
+
+    const int max_q = cfg.rc_max_quantizer;
+
+    cfg.rc_end_usage = AOM_CQ;
+    cfg.rc_max_quantizer = max_q;
+    cfg.rc_min_quantizer = max_q;
+    cfg.g_w = WIDTH;
+    cfg.g_h = HEIGHT;
+    cfg.g_lag_in_frames = 0;
+
+    aom_codec_enc_init(&enc_, algo, &cfg, 0);
+  }
+
+  ~CompressedSource() { aom_codec_destroy(&enc_); }
+
+  const aom_codec_cx_pkt_t *readFrame() {
+    uint8_t buf[WIDTH * HEIGHT * 3 / 2] = { 0 };
+
+    // render regular pattern
+    const int period = rnd_.Rand8() % 32 + 1;
+    const int phase = rnd_.Rand8() % period;
+
+    const int val_a = rnd_.Rand8();
+    const int val_b = rnd_.Rand8();
+    for (int i = 0; i < (int)sizeof buf; ++i)
+      buf[i] = (i + phase) % period < period / 2 ? val_a : val_b;
+
+    aom_image_t img;
+    aom_img_wrap(&img, AOM_IMG_FMT_I420, WIDTH, HEIGHT, 0, buf);
+    aom_codec_encode(&enc_, &img, frame_count_++, 1, 0, 0);
+
+    aom_codec_iter_t iter = NULL;
+    return aom_codec_get_cx_data(&enc_, &iter);
+  }
+
+ private:
+  ACMRandom rnd_;
+  aom_codec_ctx_t enc_;
+  int frame_count_;
+  static const int WIDTH = 32;
+  static const int HEIGHT = 32;
+};
+
+// lowers an aom_image_t to a easily comparable/printable form
+std::vector<int16_t> serialize(const aom_image_t *img) {
+  const int w_uv = ROUND_POWER_OF_TWO(img->d_w, img->x_chroma_shift);
+  const int h_uv = ROUND_POWER_OF_TWO(img->d_h, img->y_chroma_shift);
+  const int w[] = { (int)img->d_w, w_uv, w_uv };
+  const int h[] = { (int)img->d_h, h_uv, h_uv };
+
+  std::vector<int16_t> bytes;
+  bytes.reserve(img->d_w * img->d_h * 3);
+  for (int plane = 0; plane < 3; ++plane)
+    for (int r = 0; r < h[plane]; ++r)
+      for (int c = 0; c < w[plane]; ++c) {
+        const int offset = r * img->stride[plane] + c;
+        if (img->fmt & AOM_IMG_FMT_HIGHBITDEPTH)
+          bytes.push_back(img->planes[plane][offset * 2]);
+        else
+          bytes.push_back(img->planes[plane][offset]);
+      }
+
+  return bytes;
+}
+
+struct Decoder {
+  explicit Decoder(int allowLowbitdepth) {
+    aom_codec_iface_t *algo = &aom_codec_av1_dx_algo;
+
+    aom_codec_dec_cfg cfg = { 0 };
+    cfg.allow_lowbitdepth = allowLowbitdepth;
+
+    aom_codec_dec_init(&dec_, algo, &cfg, 0);
+  }
+
+  ~Decoder() { aom_codec_destroy(&dec_); }
+
+  std::vector<int16_t> decode(const aom_codec_cx_pkt_t *pkt) {
+    aom_codec_decode(&dec_, (uint8_t *)pkt->data.frame.buf, pkt->data.frame.sz,
+                     NULL, 0);
+
+    aom_codec_iter_t iter = NULL;
+    return serialize(aom_codec_get_frame(&dec_, &iter));
+  }
+
+ private:
+  aom_codec_ctx_t dec_;
+};
+
+// Try to reveal a mismatch between LBD and HBD coding paths.
+TEST(CodingPathSync, SearchForHbdLbdMismatch) {
+  // disable test. Re-enable it locally to help diagnosing LBD/HBD mismatches.
+  // And re-enable it once both coding paths match
+  // so they don't diverge anymore.
+  return;
+
+  const int count_tests = 100;
+  for (int i = 0; i < count_tests; ++i) {
+    Decoder dec_HBD(0);
+    Decoder dec_LBD(1);
+
+    CompressedSource enc(i);
+    const aom_codec_cx_pkt_t *frame = enc.readFrame();
+    ASSERT_EQ(dec_LBD.decode(frame), dec_HBD.decode(frame));
+  }
+}
+
+}  // namespace
+
+#endif

test/test.mk

@@ -33,6 +33,7 @@ LIBAOM_TEST_SRCS-$(CONFIG_AV1_ENCODER)    += altref_test.cc
 LIBAOM_TEST_SRCS-$(CONFIG_AV1_ENCODER)    += aq_segment_test.cc
 LIBAOM_TEST_SRCS-$(CONFIG_AV1_ENCODER)    += datarate_test.cc
 LIBAOM_TEST_SRCS-$(CONFIG_AV1_ENCODER)    += encode_api_test.cc
+LIBAOM_TEST_SRCS-$(CONFIG_AV1_ENCODER)    += coding_path_sync.cc
 LIBAOM_TEST_SRCS-$(CONFIG_AV1_ENCODER)    += error_resilience_test.cc
 LIBAOM_TEST_SRCS-$(CONFIG_AV1_ENCODER)    += i420_video_source.h
 #LIBAOM_TEST_SRCS-$(CONFIG_AV1_ENCODER)    += realtime_test.cc