Set non-zero target bitrate for AV1 single spatial layer case

VideoCodecInitializer::SetupCodec never sets startBitrate,
so SetAv1SvcConfig shouldn't use it.

Bug: webrtc:12720
Change-Id: I04835dc27368f32c19132d93c72364173d7050fc
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/217382
Reviewed-by: Erik Språng <sprang@webrtc.org>
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#33915}
diff --git a/modules/video_coding/video_codec_initializer_unittest.cc b/modules/video_coding/video_codec_initializer_unittest.cc
index f7fde8d..da3d80d 100644
--- a/modules/video_coding/video_codec_initializer_unittest.cc
+++ b/modules/video_coding/video_codec_initializer_unittest.cc
@@ -426,4 +426,39 @@
   EXPECT_FALSE(codec_out_.spatialLayers[2].active);
 }
 
+TEST_F(VideoCodecInitializerTest, Av1SingleSpatialLayerBitratesAreConsistent) {
+  VideoEncoderConfig config;
+  config.codec_type = VideoCodecType::kVideoCodecAV1;
+  std::vector<VideoStream> streams = {DefaultStream()};
+  streams[0].scalability_mode = "L1T2";
+
+  VideoCodec codec;
+  EXPECT_TRUE(VideoCodecInitializer::SetupCodec(config, streams, &codec));
+
+  EXPECT_GE(codec.spatialLayers[0].targetBitrate,
+            codec.spatialLayers[0].minBitrate);
+  EXPECT_LE(codec.spatialLayers[0].targetBitrate,
+            codec.spatialLayers[0].maxBitrate);
+}
+
+TEST_F(VideoCodecInitializerTest, Av1TwoSpatialLayersBitratesAreConsistent) {
+  VideoEncoderConfig config;
+  config.codec_type = VideoCodecType::kVideoCodecAV1;
+  std::vector<VideoStream> streams = {DefaultStream()};
+  streams[0].scalability_mode = "L2T2";
+
+  VideoCodec codec;
+  EXPECT_TRUE(VideoCodecInitializer::SetupCodec(config, streams, &codec));
+
+  EXPECT_GE(codec.spatialLayers[0].targetBitrate,
+            codec.spatialLayers[0].minBitrate);
+  EXPECT_LE(codec.spatialLayers[0].targetBitrate,
+            codec.spatialLayers[0].maxBitrate);
+
+  EXPECT_GE(codec.spatialLayers[1].targetBitrate,
+            codec.spatialLayers[1].minBitrate);
+  EXPECT_LE(codec.spatialLayers[1].targetBitrate,
+            codec.spatialLayers[1].maxBitrate);
+}
+
 }  // namespace webrtc