win-mf: Add Media Foundation AAC Encoder

Adds Microsoft Media Foundation AAC Encoder that supports
96k to 192k bitrates.  This plugin is only enabled on Microsoft
Windows 8+ due to performance issues found on Windows 7.

plugins/win-mf/mf-aac-encoder.hpp

@@ -0,0 +1,91 @@
+#pragma once
+
+#define WIN32_MEAN_AND_LEAN
+#include <Windows.h>
+#undef WIN32_MEAN_AND_LEAN
+
+#include <mfapi.h>
+#include <mfidl.h>
+
+#include <stdint.h>
+#include <vector>
+
+#include <util/windows/ComPtr.hpp>
+
+#define MF_LOG(level, format, ...) \
+	blog(level, "[Media Foundation encoder]: " format, ##__VA_ARGS__)
+#define MF_LOG_ENCODER(format_name, encoder, level, format, ...) \
+	blog(level, "[Media Foundation %s: '%s']: " format, \
+			format_name, obs_encoder_get_name(encoder), \
+			##__VA_ARGS__)
+
+namespace MFAAC {
+
+enum Status {
+	FAILURE,
+	SUCCESS,
+	NOT_ACCEPTING,
+	NEED_MORE_INPUT
+};
+
+class Encoder {
+public:
+	Encoder(const obs_encoder_t *encoder, UINT32 bitrate, UINT32 channels,
+			UINT32 sampleRate, UINT32 bitsPerSample)
+		: encoder(encoder),
+		  bitrate(bitrate),
+		  channels(channels),
+		  sampleRate(sampleRate),
+		  bitsPerSample(bitsPerSample)
+	{}
+
+	Encoder& operator=(Encoder const&) = delete;
+
+	bool Initialize();
+	bool ProcessInput(UINT8 *data, UINT32 dataLength,
+			UINT64 pts, MFAAC::Status *status);
+	bool ProcessOutput(UINT8 **data, UINT32 *dataLength,
+			UINT64 *pts, MFAAC::Status *status);
+	bool ExtraData(UINT8 **extraData, UINT32 *extraDataLength);
+
+	const obs_encoder_t *ObsEncoder() { return encoder; }
+	UINT32 Bitrate() { return bitrate; }
+	UINT32 Channels() { return channels; }
+	UINT32 SampleRate() { return sampleRate; }
+	UINT32 BitsPerSample() { return bitsPerSample; }
+
+	static const UINT32 FrameSize = 1024;
+
+private:
+	void InitializeExtraData();
+	HRESULT CreateMediaTypes(ComPtr<IMFMediaType> &inputType,
+			ComPtr<IMFMediaType> &outputType);
+	HRESULT EnsureCapacity(ComPtr<IMFSample> &sample, DWORD length);
+	HRESULT CreateEmptySample(ComPtr<IMFSample> &sample,
+			ComPtr<IMFMediaBuffer> &buffer, DWORD length);
+
+private:
+	const obs_encoder_t *encoder;
+	const UINT32 bitrate;
+	const UINT32 channels;
+	const UINT32 sampleRate;
+	const UINT32 bitsPerSample;
+
+	ComPtr<IMFTransform> transform;
+	ComPtr<IMFSample> outputSample;
+	std::vector<BYTE> packetBuffer;
+	UINT8 extraData[5];
+};
+
+static const UINT32 FrameSize = 1024;
+
+UINT32 FindBestBitrateMatch(UINT32 value);
+UINT32 FindBestChannelsMatch(UINT32 value);
+UINT32 FindBestBitsPerSampleMatch(UINT32 value);
+UINT32 FindBestSamplerateMatch(UINT32 value);
+bool BitrateValid(UINT32 value);
+bool ChannelsValid(UINT32 value);
+bool BitsPerSampleValid(UINT32 value);
+bool SamplerateValid(UINT32 value);
+
+}