Add tests for vp9 (non-flexible mode) using different spatial and temporal configurations.

webrtc/video/video_send_stream_tests.cc

Index: webrtc/video/video_send_stream_tests.cc
diff --git a/webrtc/video/video_send_stream_tests.cc b/webrtc/video/video_send_stream_tests.cc
index a1d74757f062f8d7327b0519019e6d5db74f2ce2..d480e6eb8ca7cb6eb245bc9a3443b436d45e1846 100644
--- a/webrtc/video/video_send_stream_tests.cc
+++ b/webrtc/video/video_send_stream_tests.cc
@@ -58,6 +58,9 @@ class VideoSendStreamTest : public test::CallTest {
   void TestNackRetransmission(uint32_t retransmit_ssrc,
                               uint8_t retransmit_payload_type);
   void TestPacketFragmentationSize(VideoFormat format, bool with_fec);
+
+  void TestVp9NonFlexMode(uint8_t num_temporal_layers,
+                          uint8_t num_spatial_layers);
 };
 
 TEST_F(VideoSendStreamTest, CanStartStartedStream) {
@@ -1791,22 +1794,21 @@ TEST_F(VideoSendStreamTest, ReportsSentResolution) {
   RunBaseTest(&test, FakeNetworkPipe::Config());
 }
 
-class VP9HeaderObeserver : public test::SendTest {
+class Vp9HeaderObserver : public test::SendTest {
  public:
-  VP9HeaderObeserver()
+  Vp9HeaderObserver()
       : SendTest(VideoSendStreamTest::kDefaultTimeoutMs),
         vp9_encoder_(VP9Encoder::Create()),
-        vp9_settings_(VideoEncoder::GetDefaultVp9Settings()) {
-    vp9_settings_.numberOfTemporalLayers = 1;
-    vp9_settings_.numberOfSpatialLayers = 2;
-  }
+        vp9_settings_(VideoEncoder::GetDefaultVp9Settings()),
+        packets_sent_(0),
+        frames_sent_(0) {}
 
   virtual void ModifyConfigsHook(
       VideoSendStream::Config* send_config,
       std::vector<VideoReceiveStream::Config>* receive_configs,
       VideoEncoderConfig* encoder_config) {}
 
-  virtual void InspectHeader(RTPVideoHeaderVP9* vp9videoHeader) = 0;
+  virtual void InspectHeader(const RTPVideoHeaderVP9& vp9) = 0;
 
  private:
   const int kVp9PayloadType = 105;
@@ -1815,11 +1817,14 @@ class VP9HeaderObeserver : public test::SendTest {
                      std::vector<VideoReceiveStream::Config>* receive_configs,
                      VideoEncoderConfig* encoder_config) override {
     encoder_config->encoder_specific_settings = &vp9_settings_;
-    encoder_config->content_type = VideoEncoderConfig::ContentType::kScreen;
     send_config->encoder_settings.encoder = vp9_encoder_.get();
     send_config->encoder_settings.payload_name = "VP9";
     send_config->encoder_settings.payload_type = kVp9PayloadType;
     ModifyConfigsHook(send_config, receive_configs, encoder_config);
+    EXPECT_EQ(1u, encoder_config->streams.size());
+    encoder_config->streams[0].temporal_layer_thresholds_bps.resize(
+        vp9_settings_.numberOfTemporalLayers - 1);
+    encoder_config_ = *encoder_config;
   }
 
   void PerformTest() override {
@@ -1831,113 +1836,349 @@ class VP9HeaderObeserver : public test::SendTest {
     RTPHeader header;
     EXPECT_TRUE(parser_->Parse(packet, length, &header));
 
-    if (header.payloadType == kVp9PayloadType) {
-      RtpDepacketizerVp9 vp9depacketizer;
-      RtpDepacketizer::ParsedPayload vp9payload;
-      const uint8_t* vp9_packet = packet + header.headerLength;
-      size_t payload_length =
-          length - header.headerLength - header.paddingLength;
-
-      if (payload_length > 0) {
-        bool parse_vp9header_successful =
-            vp9depacketizer.Parse(&vp9payload, vp9_packet, payload_length);
-        bool is_vp9_codec_type =
-            vp9payload.type.Video.codec == RtpVideoCodecTypes::kRtpVideoVp9;
-        EXPECT_TRUE(parse_vp9header_successful);
-        EXPECT_TRUE(is_vp9_codec_type);
-
-        RTPVideoHeaderVP9* vp9videoHeader =
-            &vp9payload.type.Video.codecHeader.VP9;
-        if (parse_vp9header_successful && is_vp9_codec_type) {
-          InspectHeader(vp9videoHeader);
-        } else {
-          observation_complete_->Set();
-        }
+    EXPECT_EQ(kVp9PayloadType, header.payloadType);
+    const uint8_t* payload = packet + header.headerLength;
+    size_t payload_length = length - header.headerLength - header.paddingLength;
+
+    bool new_packet = packets_sent_ == 0 ||
+                      IsNewerSequenceNumber(header.sequenceNumber,
+                                            last_header_.sequenceNumber);
+    if (payload_length > 0 && new_packet) {
+      RtpDepacketizer::ParsedPayload parsed;
+      RtpDepacketizerVp9 depacketizer;
+      EXPECT_TRUE(depacketizer.Parse(&parsed, payload, payload_length));
+      EXPECT_EQ(RtpVideoCodecTypes::kRtpVideoVp9, parsed.type.Video.codec);
+      // Verify common fields for all configurations.
+      VerifyCommonHeader(parsed.type.Video.codecHeader.VP9);
+      CompareConsecutiveFrames(header, parsed.type.Video);
+      // Verify configuration specific settings.
+      InspectHeader(parsed.type.Video.codecHeader.VP9);
+
+      ++packets_sent_;
+      if (header.markerBit) {
+        ++frames_sent_;
       }
+      last_header_ = header;
+      last_vp9_ = parsed.type.Video.codecHeader.VP9;
     }
-
     return SEND_PACKET;
   }
 
  protected:
-  rtc::scoped_ptr<VP9Encoder> vp9_encoder_;
-  VideoCodecVP9 vp9_settings_;
-};
+  bool ContinuousPictureId(const RTPVideoHeaderVP9& vp9) const {
+    if (last_vp9_.picture_id > vp9.picture_id) {
+      return vp9.picture_id == 0;  // Wrap.
+    } else {
+      return vp9.picture_id == last_vp9_.picture_id + 1;
+    }
+  }
 
-TEST_F(VideoSendStreamTest, DISABLED_VP9FlexMode) {
-  class FlexibleMode : public VP9HeaderObeserver {
-    void ModifyConfigsHook(
-        VideoSendStream::Config* send_config,
-        std::vector<VideoReceiveStream::Config>* receive_configs,
-        VideoEncoderConfig* encoder_config) override {
-      vp9_settings_.flexibleMode = true;
+  void VerifySpatialIdxWithinFrame(const RTPVideoHeaderVP9& vp9) const {
+    if (frames_sent_ == 0)
+      return;
+
+    bool new_layer = vp9.spatial_idx != last_vp9_.spatial_idx;
+    EXPECT_EQ(new_layer, vp9.beginning_of_frame);
+    EXPECT_EQ(new_layer, last_vp9_.end_of_frame);
+    EXPECT_EQ(new_layer ? last_vp9_.spatial_idx + 1 : last_vp9_.spatial_idx,
+              vp9.spatial_idx);
+  }
+
+  void VerifyFixedTemporalLayerStructure(const RTPVideoHeaderVP9& vp9,
+                                         uint8_t num_layers) const {
+    switch (num_layers) {
+      case 0:
+        VerifyTemporalLayerStructure0(vp9);
+        break;
+      case 1:
+        VerifyTemporalLayerStructure1(vp9);
+        break;
+      case 2:
+        VerifyTemporalLayerStructure2(vp9);
+        break;
+      case 3:
+        VerifyTemporalLayerStructure3(vp9);
+        break;
+      default:
+        RTC_NOTREACHED();
     }
+  }
 
-    void InspectHeader(RTPVideoHeaderVP9* vp9videoHeader) override {
-      EXPECT_TRUE(vp9videoHeader->flexible_mode);
-      observation_complete_->Set();
+  void VerifyTemporalLayerStructure0(const RTPVideoHeaderVP9& vp9) const {
+    EXPECT_EQ(kNoTl0PicIdx, vp9.tl0_pic_idx);
+    EXPECT_EQ(kNoTemporalIdx, vp9.temporal_idx);  // no tid
+    EXPECT_FALSE(vp9.temporal_up_switch);
+  }
+
+  void VerifyTemporalLayerStructure1(const RTPVideoHeaderVP9& vp9) const {
+    EXPECT_NE(kNoTl0PicIdx, vp9.tl0_pic_idx);
+    EXPECT_EQ(0, vp9.temporal_idx);  // 0,0,0,...
+    EXPECT_FALSE(vp9.temporal_up_switch);
+  }
+
+  void VerifyTemporalLayerStructure2(const RTPVideoHeaderVP9& vp9) const {
+    EXPECT_NE(kNoTl0PicIdx, vp9.tl0_pic_idx);
+    EXPECT_GE(vp9.temporal_idx, 0);  // 0,1,0,1,...
+    EXPECT_LE(vp9.temporal_idx, 1);
+    EXPECT_EQ(vp9.temporal_idx > 0, vp9.temporal_up_switch);
+    if (IsNewPictureId(vp9)) {
+      uint8_t expected_tid =
+          (IsKeyFrame(vp9) || last_vp9_.temporal_idx == 1) ? 0 : 1;
+      EXPECT_EQ(expected_tid, vp9.temporal_idx);
     }
-  } test;
+  }
 
-  RunBaseTest(&test, FakeNetworkPipe::Config());
-}
+  void VerifyTemporalLayerStructure3(const RTPVideoHeaderVP9& vp9) const {
+    EXPECT_NE(kNoTl0PicIdx, vp9.tl0_pic_idx);
+    EXPECT_GE(vp9.temporal_idx, 0);  // 0,2,1,2,...
+    EXPECT_LE(vp9.temporal_idx, 2);
+    if (IsNewPictureId(vp9) && !IsKeyFrame(vp9)) {
+      EXPECT_NE(vp9.temporal_idx, last_vp9_.temporal_idx);
+      switch (vp9.temporal_idx) {
+        case 0:
+          EXPECT_EQ(2, last_vp9_.temporal_idx);
+          EXPECT_FALSE(vp9.temporal_up_switch);
+          break;
+        case 1:
+          EXPECT_EQ(2, last_vp9_.temporal_idx);
+          EXPECT_TRUE(vp9.temporal_up_switch);
+          break;
+        case 2:
+          EXPECT_EQ(last_vp9_.temporal_idx == 0, vp9.temporal_up_switch);
+          break;
+      }
+    }
+  }
 
-TEST_F(VideoSendStreamTest, VP9FlexModeHasPictureId) {
-  class FlexibleMode : public VP9HeaderObeserver {
-    void ModifyConfigsHook(
-        VideoSendStream::Config* send_config,
-        std::vector<VideoReceiveStream::Config>* receive_configs,
-        VideoEncoderConfig* encoder_config) override {
-      vp9_settings_.flexibleMode = true;
+  void VerifyTl0Idx(const RTPVideoHeaderVP9& vp9) const {
+    if (vp9.tl0_pic_idx == kNoTl0PicIdx)
+      return;
+
+    uint8_t expected_tl0_idx = last_vp9_.tl0_pic_idx;
+    if (vp9.temporal_idx == 0)
+      ++expected_tl0_idx;
+    EXPECT_EQ(expected_tl0_idx, vp9.tl0_pic_idx);
+  }
+
+  bool IsNewPictureId(const RTPVideoHeaderVP9& vp9) const {
+    return frames_sent_ > 0 && (vp9.picture_id != last_vp9_.picture_id);
+  }
+
+  bool IsKeyFrame(const RTPVideoHeaderVP9& vp9) const {

[stefan-webrtc, 2015/11/23 10:27:13]

I'm not sure if !inter_pic_predicted is enough to say that this is a key frame.
It could in theory be an intra frame which doesn't update all reference buffers,
or a layer frame which only uses inter-layer prediction, where the layer below
is using inter-picture prediction.

I saw that we had a TODO in vp9_impl.cc:
  // TODO(asapersson): Set correct values.
  vp9_info->inter_pic_predicted =
      (pkt.data.frame.flags & VPX_FRAME_IS_KEY) ? false : true;

Is that TODO referring to the same thing as I mention above?

[åsapersson, 2015/11/23 15:01:49]

For the second example (layer frame using inter-layer pred and layer below using
inter-pic pred) I am not sure it would be flagged as a key frame? (And the flag
is used to set inter_pic_prediction).

I removed this todo. That referred to the todos below: that some values should
be obtained from the encoder (temporal up switch, etc). Also removed this
function.

+    return !vp9.inter_pic_predicted;  // P
+  }
+
+  bool IsFirstPacketInKeyFrame(const RTPVideoHeaderVP9& vp9) const {
+    return IsKeyFrame(vp9) && vp9.beginning_of_frame && vp9.spatial_idx == 0;
+  }
+
+  // Flexible mode (F=1):    Non-flexible mode (F=0):
+  //
+  //      +-+-+-+-+-+-+-+-+     +-+-+-+-+-+-+-+-+
+  //      |I|P|L|F|B|E|V|-|     |I|P|L|F|B|E|V|-|
+  //      +-+-+-+-+-+-+-+-+     +-+-+-+-+-+-+-+-+
+  // I:   |M| PICTURE ID  |  I: |M| PICTURE ID  |
+  //      +-+-+-+-+-+-+-+-+     +-+-+-+-+-+-+-+-+
+  // M:   | EXTENDED PID  |  M: | EXTENDED PID  |
+  //      +-+-+-+-+-+-+-+-+     +-+-+-+-+-+-+-+-+
+  // L:   |  T  |U|  S  |D|  L: |  T  |U|  S  |D|
+  //      +-+-+-+-+-+-+-+-+     +-+-+-+-+-+-+-+-+
+  // P,F: | P_DIFF    |X|N|     |   TL0PICIDX   |
+  //      +-+-+-+-+-+-+-+-+     +-+-+-+-+-+-+-+-+
+  // X:   |EXTENDED P_DIFF|  V: | SS  ..        |
+  //      +-+-+-+-+-+-+-+-+     +-+-+-+-+-+-+-+-+
+  // V:   | SS  ..        |
+  //      +-+-+-+-+-+-+-+-+
+  void VerifyCommonHeader(const RTPVideoHeaderVP9& vp9) const {
+    EXPECT_EQ(kMaxTwoBytePictureId, vp9.max_picture_id);  // M:1
+    EXPECT_NE(kNoPictureId, vp9.picture_id);              // I:1
+    EXPECT_EQ(vp9_settings_.flexibleMode, vp9.flexible_mode);  // F
+    EXPECT_GE(vp9.spatial_idx, 0);                             // S
+    EXPECT_LT(vp9.spatial_idx, vp9_settings_.numberOfSpatialLayers);
+    if (vp9.ss_data_available)  // V
+      VerifySsData(vp9);
+
+    if (packets_sent_ == 0)
+      EXPECT_TRUE(IsFirstPacketInKeyFrame(vp9));
+    if (frames_sent_ == 0)
+      EXPECT_TRUE(IsKeyFrame(vp9));
+
+    if (IsKeyFrame(vp9)) {
+      EXPECT_TRUE(vp9.temporal_idx == 0 || vp9.temporal_idx == kNoTemporalIdx);
+      EXPECT_FALSE(vp9.temporal_up_switch);
     }
+  }
 
-    void InspectHeader(RTPVideoHeaderVP9* vp9videoHeader) override {
-      EXPECT_NE(vp9videoHeader->picture_id, kNoPictureId);
-      observation_complete_->Set();
+  // Scalability structure (SS).
+  //
+  //      +-+-+-+-+-+-+-+-+
+  // V:   | N_S |Y|G|-|-|-|
+  //      +-+-+-+-+-+-+-+-+
+  // Y:   |    WIDTH      |  N_S + 1 times
+  //      +-+-+-+-+-+-+-+-+
+  //      |    HEIGHT     |
+  //      +-+-+-+-+-+-+-+-+
+  // G:   |      N_G      |
+  //      +-+-+-+-+-+-+-+-+
+  // N_G: |  T  |U| R |-|-|  N_G times
+  //      +-+-+-+-+-+-+-+-+
+  //      |    P_DIFF     |  R times
+  //      +-+-+-+-+-+-+-+-+
+  void VerifySsData(const RTPVideoHeaderVP9& vp9) const {
+    EXPECT_TRUE(vp9.ss_data_available);             // V
+    EXPECT_EQ(vp9_settings_.numberOfSpatialLayers,  // N_S + 1
+              vp9.num_spatial_layers);
+    EXPECT_TRUE(vp9.spatial_layer_resolution_present);  // Y:1
+    size_t expected_width = encoder_config_.streams[0].width;
+    size_t expected_height = encoder_config_.streams[0].height;
+    for (int i = vp9.num_spatial_layers - 1; i >= 0; --i) {
+      EXPECT_EQ(expected_width, vp9.width[i]);    // WIDTH
+      EXPECT_EQ(expected_height, vp9.height[i]);  // HEIGHT
+      expected_width /= 2;
+      expected_height /= 2;
     }
-  } test;
+  }
 
-  RunBaseTest(&test, FakeNetworkPipe::Config());
+  void CompareConsecutiveFrames(const RTPHeader& header,
+                                const RTPVideoHeader& video) const {
+    const RTPVideoHeaderVP9& vp9 = video.codecHeader.VP9;
+
+    bool new_frame = packets_sent_ == 0 ||
+                     IsNewerTimestamp(header.timestamp, last_header_.timestamp);
+    EXPECT_EQ(new_frame, video.isFirstPacket);
+    if (!new_frame) {
+      EXPECT_FALSE(last_header_.markerBit);
+      EXPECT_EQ(last_header_.timestamp, header.timestamp);
+      EXPECT_EQ(last_vp9_.picture_id, vp9.picture_id);
+      EXPECT_EQ(last_vp9_.temporal_idx, vp9.temporal_idx);
+      EXPECT_EQ(last_vp9_.tl0_pic_idx, vp9.tl0_pic_idx);
+      VerifySpatialIdxWithinFrame(vp9);
+      return;
+    }
+    // New frame.
+    EXPECT_TRUE(vp9.beginning_of_frame);
+
+    // Compare with last packet in previous frame.
+    if (frames_sent_ == 0)
+      return;
+    EXPECT_TRUE(last_vp9_.end_of_frame);
+    EXPECT_TRUE(last_header_.markerBit);
+    EXPECT_TRUE(ContinuousPictureId(vp9));
+    VerifyTl0Idx(vp9);
+  }
+
+  rtc::scoped_ptr<VP9Encoder> vp9_encoder_;
+  VideoCodecVP9 vp9_settings_;
+  webrtc::VideoEncoderConfig encoder_config_;
+  RTPHeader last_header_;
+  RTPVideoHeaderVP9 last_vp9_;
+  size_t packets_sent_;
+  size_t frames_sent_;
+};
+
+TEST_F(VideoSendStreamTest, Vp9NonFlexMode_1Tl1SLayers) {
+  const uint8_t kNumTemporalLayers = 1;
+  const uint8_t kNumSpatialLayers = 1;
+  TestVp9NonFlexMode(kNumTemporalLayers, kNumSpatialLayers);
+}
+
+TEST_F(VideoSendStreamTest, Vp9NonFlexMode_2Tl1SLayers) {
+  const uint8_t kNumTemporalLayers = 2;
+  const uint8_t kNumSpatialLayers = 1;
+  TestVp9NonFlexMode(kNumTemporalLayers, kNumSpatialLayers);
+}
+
+TEST_F(VideoSendStreamTest, Vp9NonFlexMode_3Tl1SLayers) {
+  const uint8_t kNumTemporalLayers = 3;
+  const uint8_t kNumSpatialLayers = 1;
+  TestVp9NonFlexMode(kNumTemporalLayers, kNumSpatialLayers);
+}
+
+TEST_F(VideoSendStreamTest, Vp9NonFlexMode_1Tl2SLayers) {
+  const uint8_t kNumTemporalLayers = 1;
+  const uint8_t kNumSpatialLayers = 2;
+  TestVp9NonFlexMode(kNumTemporalLayers, kNumSpatialLayers);
 }
 
-TEST_F(VideoSendStreamTest, VP9FlexModeRefCount) {
-  class FlexibleMode : public VP9HeaderObeserver {
+TEST_F(VideoSendStreamTest, Vp9NonFlexMode_2Tl2SLayers) {
+  const uint8_t kNumTemporalLayers = 2;
+  const uint8_t kNumSpatialLayers = 2;
+  TestVp9NonFlexMode(kNumTemporalLayers, kNumSpatialLayers);
+}
+
+TEST_F(VideoSendStreamTest, Vp9NonFlexMode_3Tl2SLayers) {
+  const uint8_t kNumTemporalLayers = 3;
+  const uint8_t kNumSpatialLayers = 2;
+  TestVp9NonFlexMode(kNumTemporalLayers, kNumSpatialLayers);
+}
+
+void VideoSendStreamTest::TestVp9NonFlexMode(uint8_t num_temporal_layers,
+                                             uint8_t num_spatial_layers) {
+  static const size_t kNumFramesToSend = 100;
+  // Set to < kNumFramesToSend and coprime to length of temporal layer
+  // structures to verify temporal id reset on key frame.
+  static const int kKeyFrameInterval = 31;
+  class NonFlexibleMode : public Vp9HeaderObserver {
+   public:
+    NonFlexibleMode(uint8_t num_temporal_layers, uint8_t num_spatial_layers)
+        : num_temporal_layers_(num_temporal_layers),
+          num_spatial_layers_(num_spatial_layers),
+          l_field_(num_temporal_layers > 1 || num_spatial_layers > 1) {
+    }
     void ModifyConfigsHook(
         VideoSendStream::Config* send_config,
         std::vector<VideoReceiveStream::Config>* receive_configs,
         VideoEncoderConfig* encoder_config) override {
-      vp9_settings_.flexibleMode = true;
+      vp9_settings_.flexibleMode = false;
+      vp9_settings_.frameDroppingOn = false;
+      vp9_settings_.keyFrameInterval = kKeyFrameInterval;
+      vp9_settings_.numberOfTemporalLayers = num_temporal_layers_;
+      vp9_settings_.numberOfSpatialLayers = num_spatial_layers_;
     }
 
-    void InspectHeader(RTPVideoHeaderVP9* vp9videoHeader) override {
-      EXPECT_TRUE(vp9videoHeader->flexible_mode);
-      if (vp9videoHeader->inter_pic_predicted) {
-        EXPECT_GT(vp9videoHeader->num_ref_pics, 0u);
-        observation_complete_->Set();
+    void InspectHeader(const RTPVideoHeaderVP9& vp9) override {
+      EXPECT_EQ(IsFirstPacketInKeyFrame(vp9), vp9.ss_data_available);
+      EXPECT_EQ(vp9.spatial_idx > 0, vp9.inter_layer_predicted);  // D
+
+      if (IsNewPictureId(vp9)) {
+        EXPECT_EQ(0, vp9.spatial_idx);
+        EXPECT_EQ(num_spatial_layers_ - 1, last_vp9_.spatial_idx);
       }
+
+      VerifyFixedTemporalLayerStructure(vp9,
+                                        l_field_ ? num_temporal_layers_ : 0);
+
+      if (frames_sent_ > kNumFramesToSend)
+        observation_complete_->Set();
     }
-  } test;
+    const uint8_t num_temporal_layers_;
+    const uint8_t num_spatial_layers_;
+    const bool l_field_;
+  } test(num_temporal_layers, num_spatial_layers);
 
   RunBaseTest(&test, FakeNetworkPipe::Config());
 }
 
-TEST_F(VideoSendStreamTest, VP9FlexModeRefs) {
-  class FlexibleMode : public VP9HeaderObeserver {
+TEST_F(VideoSendStreamTest, Vp9FlexModeRefCount) {
+  class FlexibleMode : public Vp9HeaderObserver {
     void ModifyConfigsHook(
         VideoSendStream::Config* send_config,
         std::vector<VideoReceiveStream::Config>* receive_configs,
         VideoEncoderConfig* encoder_config) override {
+      encoder_config->content_type = VideoEncoderConfig::ContentType::kScreen;
       vp9_settings_.flexibleMode = true;
+      vp9_settings_.numberOfTemporalLayers = 1;
+      vp9_settings_.numberOfSpatialLayers = 2;
     }
 
-    void InspectHeader(RTPVideoHeaderVP9* vp9videoHeader) override {
-      EXPECT_TRUE(vp9videoHeader->flexible_mode);
-      if (vp9videoHeader->inter_pic_predicted) {
-        EXPECT_GT(vp9videoHeader->num_ref_pics, 0u);
+    void InspectHeader(const RTPVideoHeaderVP9& vp9_header) override {
+      EXPECT_TRUE(vp9_header.flexible_mode);
+      EXPECT_EQ(kNoTl0PicIdx, vp9_header.tl0_pic_idx);
+      if (vp9_header.inter_pic_predicted) {
+        EXPECT_GT(vp9_header.num_ref_pics, 0u);
         observation_complete_->Set();
       }
     }
-
   } test;
 
   RunBaseTest(&test, FakeNetworkPipe::Config());