Tests kf_max_dist in one-pass zero-lag encoding

The test shows that the comment for kf_max_dist in vpx/vpx_encoder.h
differs from its behavior by one. We should modify the comment to match
the encoding behavior.

Bug: webm:1829
Change-Id: Icdc58b8f6b25353f10ce8ecc481c862bd3fe86df

1 files changed, 107 insertions, 0 deletions

diff --git a/test/keyframe_test.cc b/test/keyframe_test.cc
index dabf88e41..5292bb188 100644
--- a/test/keyframe_test.cc
+++ b/test/keyframe_test.cc
@@ -8,12 +8,18 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 #include <climits>
+#include <cstring>
 #include <vector>
 #include "third_party/googletest/src/include/gtest/gtest.h"
 #include "test/codec_factory.h"
 #include "test/encode_test_driver.h"
 #include "test/i420_video_source.h"
 #include "test/util.h"
+#include "./vpx_config.h"
+#include "vpx/vp8cx.h"
+#include "vpx/vpx_codec.h"
+#include "vpx/vpx_encoder.h"
+#include "vpx/vpx_image.h"
 
 namespace {
 
@@ -146,4 +152,105 @@ TEST_P(KeyframeTest, TestAutoKeyframe) {
 }
 
 VP8_INSTANTIATE_TEST_SUITE(KeyframeTest, ALL_TEST_MODES);
+
+bool IsVP9(vpx_codec_iface_t *iface) {
+  static const char kVP9Name[] = "WebM Project VP9";
+  return strncmp(kVP9Name, vpx_codec_iface_name(iface), sizeof(kVP9Name) - 1) ==
+         0;
+}
+
+vpx_image_t *CreateGrayImage(vpx_img_fmt_t fmt, unsigned int w,
+                             unsigned int h) {
+  vpx_image_t *const image = vpx_img_alloc(nullptr, fmt, w, h, 1);
+  if (!image) return image;
+
+  for (unsigned int i = 0; i < image->d_h; ++i) {
+    memset(image->planes[0] + i * image->stride[0], 128, image->d_w);
+  }
+  const unsigned int uv_h = (image->d_h + 1) / 2;
+  const unsigned int uv_w = (image->d_w + 1) / 2;
+  for (unsigned int i = 0; i < uv_h; ++i) {
+    memset(image->planes[1] + i * image->stride[1], 128, uv_w);
+    memset(image->planes[2] + i * image->stride[2], 128, uv_w);
+  }
+  return image;
+}
+
+// Tests kf_max_dist in one-pass encoding with zero lag.
+void TestKeyframeMaximumInterval(vpx_codec_iface_t *iface,
+                                 unsigned long deadline,
+                                 unsigned int kf_max_dist) {
+  vpx_codec_enc_cfg_t cfg;
+  ASSERT_EQ(vpx_codec_enc_config_default(iface, &cfg, /*usage=*/0),
+            VPX_CODEC_OK);
+  cfg.g_w = 320;
+  cfg.g_h = 240;
+  cfg.g_pass = VPX_RC_ONE_PASS;
+  cfg.g_lag_in_frames = 0;
+  cfg.kf_mode = VPX_KF_AUTO;
+  cfg.kf_min_dist = 0;
+  cfg.kf_max_dist = kf_max_dist;
+
+  vpx_codec_ctx_t enc;
+  ASSERT_EQ(vpx_codec_enc_init(&enc, iface, &cfg, 0), VPX_CODEC_OK);
+
+  const int speed = IsVP9(iface) ? 9 : -12;
+  ASSERT_EQ(vpx_codec_control(&enc, VP8E_SET_CPUUSED, speed), VPX_CODEC_OK);
+
+  vpx_image_t *image = CreateGrayImage(VPX_IMG_FMT_I420, cfg.g_w, cfg.g_h);
+  ASSERT_NE(image, nullptr);
+
+  // Encode frames.
+  const vpx_codec_cx_pkt_t *pkt;
+  const unsigned int num_frames = kf_max_dist == 0 ? 4 : 3 * kf_max_dist + 1;
+  for (unsigned int i = 0; i < num_frames; ++i) {
+    ASSERT_EQ(vpx_codec_encode(&enc, image, i, 1, 0, deadline), VPX_CODEC_OK);
+    vpx_codec_iter_t iter = nullptr;
+    while ((pkt = vpx_codec_get_cx_data(&enc, &iter)) != nullptr) {
+      ASSERT_EQ(pkt->kind, VPX_CODEC_CX_FRAME_PKT);
+      if (kf_max_dist == 0 || i % kf_max_dist == 0) {
+        ASSERT_EQ(pkt->data.frame.flags & VPX_FRAME_IS_KEY, VPX_FRAME_IS_KEY);
+      } else {
+        ASSERT_EQ(pkt->data.frame.flags & VPX_FRAME_IS_KEY, 0u);
+      }
+    }
+  }
+
+  // Flush the encoder.
+  bool got_data;
+  do {
+    ASSERT_EQ(vpx_codec_encode(&enc, nullptr, 0, 1, 0, deadline), VPX_CODEC_OK);
+    got_data = false;
+    vpx_codec_iter_t iter = nullptr;
+    while ((pkt = vpx_codec_get_cx_data(&enc, &iter)) != nullptr) {
+      ASSERT_EQ(pkt->kind, VPX_CODEC_CX_FRAME_PKT);
+      got_data = true;
+    }
+  } while (got_data);
+
+  vpx_img_free(image);
+  ASSERT_EQ(vpx_codec_destroy(&enc), VPX_CODEC_OK);
+}
+
+TEST(KeyframeIntervalTest, KeyframeMaximumInterval) {
+  std::vector<vpx_codec_iface_t *> ifaces;
+#if CONFIG_VP8_ENCODER
+  ifaces.push_back(vpx_codec_vp8_cx());
+#endif
+#if CONFIG_VP9_ENCODER
+  ifaces.push_back(vpx_codec_vp9_cx());
+#endif
+  for (vpx_codec_iface_t *iface : ifaces) {
+    for (unsigned long deadline :
+         { VPX_DL_REALTIME, VPX_DL_GOOD_QUALITY, VPX_DL_BEST_QUALITY }) {
+      // Test 0 and 1 (both mean all intra), some powers of 2, some multiples
+      // of 10, and some prime numbers.
+      for (unsigned int kf_max_dist :
+           { 0, 1, 2, 3, 4, 7, 10, 13, 16, 20, 23, 29, 32 }) {
+        TestKeyframeMaximumInterval(iface, deadline, kf_max_dist);
+      }
+    }
+  }
+}
+
 }  // namespace