capture audio from CEF

Author: niklaspandersson

src/core/frame/frame.cpp

@@ -82,6 +82,7 @@ const array<std::uint8_t>& mutable_frame::image_data(std::size_t index) const {
 const array<std::int32_t>& mutable_frame::audio_data() const { return impl_->audio_data_; }
 array<std::uint8_t>&       mutable_frame::image_data(std::size_t index) { return impl_->image_data_.at(index); }
 array<std::int32_t>&       mutable_frame::audio_data() { return impl_->audio_data_; }
+void                       mutable_frame::set_audio_data(caspar::array<int32_t>&& audio) { impl_->audio_data_ = std::move(audio); }
 std::size_t                mutable_frame::width() const { return impl_->desc_.planes.at(0).width; }
 std::size_t                mutable_frame::height() const { return impl_->desc_.planes.at(0).height; }
 const frame_geometry&      mutable_frame::geometry() const { return impl_->geometry_; }

src/core/frame/frame.h

@@ -30,7 +30,7 @@ class mutable_frame final
     ~mutable_frame();
 
     mutable_frame& operator=(const mutable_frame&) = delete;
-    mutable_frame& operator                        =(mutable_frame&& other);
+    mutable_frame& operator=(mutable_frame&& other);
 
     void swap(mutable_frame& other);
 
@@ -41,6 +41,7 @@ class mutable_frame final
 
     array<std::int32_t>&       audio_data();
     const array<std::int32_t>& audio_data() const;
+    void                       set_audio_data(caspar::array<int32_t>&& audio);
 
     std::size_t width() const;
 

src/modules/ffmpeg/CMakeLists.txt

@@ -5,6 +5,7 @@ set(SOURCES
 	producer/av_producer.cpp
 	producer/av_input.cpp
 	util/av_util.cpp
+	util/audio_resampler.cpp
 	producer/ffmpeg_producer.cpp
 	consumer/ffmpeg_consumer.cpp
 	ffmpeg.cpp
@@ -14,6 +15,7 @@ set(HEADERS
 	producer/av_producer.h
 	producer/av_input.h
 	util/av_util.h
+	util/audio_resampler.h
 	producer/ffmpeg_producer.h
 	consumer/ffmpeg_consumer.h
 	ffmpeg.h

src/modules/ffmpeg/util/audio_resampler.cpp

@@ -0,0 +1,38 @@
+#include "audio_resampler.h"
+#include "av_assert.h"
+
+extern "C" {
+#include <libavutil/samplefmt.h>
+#include <libswresample/swresample.h>
+}
+
+namespace caspar { namespace ffmpeg {
+
+AudioResampler::AudioResampler(int64_t sample_rate, AVSampleFormat in_sample_fmt)
+    : ctx(std::shared_ptr<SwrContext>(swr_alloc_set_opts(nullptr,
+                                                         AV_CH_LAYOUT_7POINT1,
+                                                         AV_SAMPLE_FMT_S32,
+                                                         sample_rate,
+                                                         AV_CH_LAYOUT_7POINT1,
+                                                         in_sample_fmt,
+                                                         sample_rate,
+                                                         0,
+                                                         nullptr),
+                                      [](SwrContext* ptr) { swr_free(&ptr); }))
+{
+    if (!ctx)
+        FF_RET(AVERROR(ENOMEM), "swr_alloc_set_opts");
+
+    FF_RET(swr_init(ctx.get()), "swr_init");
+}
+
+caspar::array<int32_t> AudioResampler::convert(int frames, const void** src)
+{
+    auto result = caspar::array<int32_t>(frames * 8 * sizeof(int32_t));
+    auto ptr    = result.data();
+    auto ret    = swr_convert(ctx.get(), (uint8_t**)&ptr, frames, reinterpret_cast<const uint8_t**>(src), frames);
+
+    return result;
+}
+
+}}; // namespace caspar::ffmpeg

src/modules/ffmpeg/util/audio_resampler.h

@@ -0,0 +1,25 @@
+#include <common/array.h>
+#include <memory>
+
+extern "C" {
+#include <libavutil/samplefmt.h>
+}
+
+struct SwrContext;
+
+namespace caspar { namespace ffmpeg {
+
+class AudioResampler
+{
+    std::shared_ptr<SwrContext> ctx;
+
+  public:
+    AudioResampler(int64_t sample_rate, AVSampleFormat in_sample_fmt);
+
+    AudioResampler(const AudioResampler&)            = delete;
+    AudioResampler& operator=(const AudioResampler&) = delete;
+
+    caspar::array<int32_t> convert(int frames, const void** src);
+};
+
+}}; // namespace caspar::ffmpeg

src/modules/html/CMakeLists.txt

@@ -21,6 +21,7 @@ include_directories(../..)
 include_directories(${BOOST_INCLUDE_PATH})
 include_directories(${TBB_INCLUDE_PATH})
 include_directories(${CEF_INCLUDE_PATH})
+include_directories(${FFMPEG_INCLUDE_PATH})
 
 set_target_properties(html PROPERTIES FOLDER modules)
 source_group(sources\\producer producer/*)
@@ -29,7 +30,7 @@ source_group(sources ./*)
 target_link_libraries(html
 	common
 	core
-
+	ffmpeg
 	${CEF_BIN_PATH}/libcef.so
 	${CEF_BIN_PATH}/libcef_dll_wrapper.a
 )