From 79aab3ff51105d7ef38152e27cfcdb513313a6db Mon Sep 17 00:00:00 2001
From: philipel <philipel@webrtc.org>
Date: Mon, 26 Mar 2018 14:31:23 +0200
Subject: [PATCH] VideoStreamDecoderImpl implementation, part 2.

In this CL the GetDecoder support function is implemented. It will
be called from the (not yet existing) Decode function whenever a
frame is about to be decoded in order to get the correct decoder for
the current frame.

Bug: webrtc:8909
Change-Id: I35e40c108fb652d566b1a5fdff60a703f5615406
Reviewed-on: https://webrtc-review.googlesource.com/64448
Reviewed-by: Niels Moller <nisse@webrtc.org>
Reviewed-by: Stefan Holmer <stefan@webrtc.org>
Commit-Queue: Philip Eliasson <philipel@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22627}
---
 video/video_stream_decoder_impl.cc | 44 ++++++++++++++++++++++++++++++
 video/video_stream_decoder_impl.h  |  5 ++++
 2 files changed, 49 insertions(+)

diff --git a/video/video_stream_decoder_impl.cc b/video/video_stream_decoder_impl.cc
index fc164901a9..3a9751e67f 100644
--- a/video/video_stream_decoder_impl.cc
+++ b/video/video_stream_decoder_impl.cc
@@ -67,4 +67,48 @@ void VideoStreamDecoderImpl::OnFrame(
   }
 }
 
+VideoDecoder* VideoStreamDecoderImpl::GetDecoder(int payload_type) {
+  if (current_payload_type_ == payload_type) {
+    RTC_DCHECK(decoder_);
+    return decoder_.get();
+  }
+
+  current_payload_type_.reset();
+  decoder_.reset();
+
+  auto decoder_settings_it = decoder_settings_.find(payload_type);
+  if (decoder_settings_it == decoder_settings_.end()) {
+    RTC_LOG(LS_WARNING) << "Payload type " << payload_type
+                        << " not registered.";
+    return nullptr;
+  }
+
+  const SdpVideoFormat& video_format = decoder_settings_it->second.first;
+  std::unique_ptr<VideoDecoder> decoder =
+      decoder_factory_->CreateVideoDecoder(video_format);
+  if (!decoder) {
+    RTC_LOG(LS_WARNING) << "Failed to create decoder for payload type "
+                        << payload_type << ".";
+    return nullptr;
+  }
+
+  int num_cores = decoder_settings_it->second.second;
+  int32_t init_result = decoder->InitDecode(nullptr, num_cores);
+  if (init_result != WEBRTC_VIDEO_CODEC_OK) {
+    RTC_LOG(LS_WARNING) << "Failed to initialize decoder for payload type "
+                        << payload_type << ".";
+    return nullptr;
+  }
+
+  int32_t register_result = decoder->RegisterDecodeCompleteCallback(this);
+  if (register_result != WEBRTC_VIDEO_CODEC_OK) {
+    RTC_LOG(LS_WARNING) << "Failed to register decode callback.";
+    return nullptr;
+  }
+
+  current_payload_type_.emplace(payload_type);
+  decoder_ = std::move(decoder);
+  return decoder_.get();
+}
+
 }  // namespace webrtc
diff --git a/video/video_stream_decoder_impl.h b/video/video_stream_decoder_impl.h
index 97de050104..55751764ef 100644
--- a/video/video_stream_decoder_impl.h
+++ b/video/video_stream_decoder_impl.h
@@ -15,6 +15,7 @@
 #include <memory>
 #include <utility>
 
+#include "api/optional.h"
 #include "api/video/video_stream_decoder.h"
 #include "modules/video_coding/frame_buffer2.h"
 #include "modules/video_coding/jitter_estimator.h"
@@ -38,6 +39,8 @@ class VideoStreamDecoderImpl : public VideoStreamDecoder,
   void OnFrame(std::unique_ptr<video_coding::EncodedFrame> frame) override;
 
  private:
+  VideoDecoder* GetDecoder(int payload_type);
+
   // Implements DecodedImageCallback interface
   int32_t Decoded(VideoFrame& decodedImage) override;
   int32_t Decoded(VideoFrame& decodedImage, int64_t decode_time_ms) override;
@@ -60,6 +63,8 @@ class VideoStreamDecoderImpl : public VideoStreamDecoder,
   VCMTiming timing_;
   video_coding::FrameBuffer frame_buffer_;
   video_coding::VideoLayerFrameId last_continuous_id_;
+  rtc::Optional<int> current_payload_type_;
+  std::unique_ptr<VideoDecoder> decoder_;
 };
 
 }  // namespace webrtc