H.264 video codec support using OpenH264/FFmpeg

webrtc/modules/video_coding/codecs/h264/h264.cc

Index: webrtc/modules/video_coding/codecs/h264/h264.cc
diff --git a/webrtc/modules/video_coding/codecs/h264/h264.cc b/webrtc/modules/video_coding/codecs/h264/h264.cc
index d4123a2e777d7ecad519d9fe8b406eebe0777e63..6060caf1dbeddab9da71461a556582e403ca624a 100644
--- a/webrtc/modules/video_coding/codecs/h264/h264.cc
+++ b/webrtc/modules/video_coding/codecs/h264/h264.cc
@@ -11,6 +11,10 @@
 
 #include "webrtc/modules/video_coding/codecs/h264/include/h264.h"
 
+#if defined(WEBRTC_OPENH264)
+#include "webrtc/modules/video_coding/codecs/h264/h264_encoder_impl.h"
+#include "webrtc/modules/video_coding/codecs/h264/h264_decoder_impl.h"
+#endif
 #if defined(WEBRTC_IOS)
 #include "webrtc/modules/video_coding/codecs/h264/h264_video_toolbox_decoder.h"
 #include "webrtc/modules/video_coding/codecs/h264/h264_video_toolbox_encoder.h"
@@ -27,9 +31,33 @@ namespace webrtc {
 extern bool IsH264CodecSupportedObjC();
 #endif
 
+// If any H.264 codec is supported (iOS HW or OpenH264).
 bool IsH264CodecSupported() {
 #if defined(WEBRTC_IOS)
-  return IsH264CodecSupportedObjC();
+  if (IsH264CodecSupportedObjC()) {
+    return true;
+  }
+#endif
+#if defined(WEBRTC_OPENH264)
+  return true;
+#else
+  return false;
+#endif
+}
+
+// If H.264 codec is supported and OpenH264 is the implementation used, meaning
+// H264EncoderImpl and H264DecoderImpl.
+bool IsOpenH264CodecSupported() {
+#if defined(WEBRTC_OPENH264)
+  #if defined(WEBRTC_IOS)
+    // If on iOS and we have HW H.264 support we will prefer that over OpenH264
+    // and say that OpenH264 is not supported (even though some H264 is).
+    // TODO(hbos): If we could support both HW and SW implementations then we
+    // should do so and have the ability to choose.
+    return !IsH264CodecSupportedObjC();
+  #else
+    return true;
+  #endif
 #else
   return false;
 #endif
@@ -38,29 +66,49 @@ bool IsH264CodecSupported() {
 H264Encoder* H264Encoder::Create() {
   DCHECK(H264Encoder::IsSupported());
 #if defined(WEBRTC_IOS) && defined(WEBRTC_VIDEO_TOOLBOX_SUPPORTED)
-  return new H264VideoToolboxEncoder();
-#else
+  if (IsH264CodecSupportedObjC()) {
+    return new H264VideoToolboxEncoder();
+  }
+#endif
+#if defined(WEBRTC_OPENH264)
+  if (IsOpenH264CodecSupported()) {
+    return new H264EncoderImpl();
+  }
+#endif
   RTC_NOTREACHED();
   return nullptr;
-#endif
 }
 
 bool H264Encoder::IsSupported() {
   return IsH264CodecSupported();
 }
 
+bool H264Encoder::IsSupportedOpenH264() {
+  return IsOpenH264CodecSupported();
+}
+
 H264Decoder* H264Decoder::Create() {
   DCHECK(H264Decoder::IsSupported());
 #if defined(WEBRTC_IOS) && defined(WEBRTC_VIDEO_TOOLBOX_SUPPORTED)
-  return new H264VideoToolboxDecoder();
-#else
+  if (IsH264CodecSupportedObjC()) {
+    return new H264VideoToolboxDecoder();
+  }
+#endif
+#if defined(WEBRTC_OPENH264)
+  if (IsOpenH264CodecSupported()) {
+    return new H264DecoderImpl();
+  }
+#endif
   RTC_NOTREACHED();
   return nullptr;
-#endif
 }
 
 bool H264Decoder::IsSupported() {
   return IsH264CodecSupported();
 }
 
+bool H264Decoder::IsSupportedOpenH264() {
+  return IsOpenH264CodecSupported();
+}
+
 }  // namespace webrtc