diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3d5801063..4d0a7b77d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -17,6 +17,7 @@ set(BUILD_STATIC OFF CACHE BOOL "Build a static library")
 set(BUILD_SHARED ON CACHE BOOL "Build a shared library")
 file(GLOB ARM_SRC ${CMAKE_SOURCE_DIR}/src/arm/*.c)
 file(GLOB GBA_SRC ${CMAKE_SOURCE_DIR}/src/gba/*.c)
+file(GLOB GBA_RR_SRC ${CMAKE_SOURCE_DIR}/src/gba/rr/*.c)
 file(GLOB GBA_SV_SRC ${CMAKE_SOURCE_DIR}/src/gba/supervisor/*.c)
 file(GLOB UTIL_SRC ${CMAKE_SOURCE_DIR}/src/util/*.[cSs])
 file(GLOB VFS_SRC ${CMAKE_SOURCE_DIR}/src/util/vfs/*.c)
@@ -25,7 +26,7 @@ file(GLOB THIRD_PARTY_SRC ${CMAKE_SOURCE_DIR}/src/third-party/inih/*.c)
 list(APPEND UTIL_SRC ${CMAKE_SOURCE_DIR}/src/platform/commandline.c)
 source_group("ARM core" FILES ${ARM_SRC})
 source_group("GBA board" FILES ${GBA_SRC} ${RENDERER_SRC})
-source_group("GBA supervisor" FILES ${GBA_SV_SRC})
+source_group("GBA supervisor" FILES ${GBA_SV_SRC} ${GBA_RR_SRC})
 source_group("Utilities" FILES ${UTIL_SRC} ${VFS_SRC}})
 include_directories(${CMAKE_SOURCE_DIR}/src/arm)
 include_directories(${CMAKE_SOURCE_DIR}/src)
@@ -272,6 +273,7 @@ endif()
 set(SRC
 	${ARM_SRC}
 	${GBA_SRC}
+	${GBA_RR_SRC}
 	${GBA_SV_SRC}
 	${DEBUGGER_SRC}
 	${RENDERER_SRC}
diff --git a/src/gba/gba.c b/src/gba/gba.c
index 88d546b10..07dcc512b 100644
--- a/src/gba/gba.c
+++ b/src/gba/gba.c
@@ -106,7 +106,7 @@ void GBADestroy(struct GBA* gba) {
 	GBAVideoDeinit(&gba->video);
 	GBAAudioDeinit(&gba->audio);
 	GBASIODeinit(&gba->sio);
-	GBARRContextDestroy(gba);
+	gba->rr = 0;
 }
 
 void GBAInterruptHandlerInit(struct ARMInterruptHandler* irqh) {
@@ -130,7 +130,7 @@ void GBAReset(struct ARMCore* cpu) {
 	cpu->gprs[ARM_SP] = SP_BASE_SYSTEM;
 
 	struct GBA* gba = (struct GBA*) cpu->master;
-	if (!GBARRIsPlaying(gba->rr) && !GBARRIsRecording(gba->rr)) {
+	if (!gba->rr || (!gba->rr->isPlaying(gba->rr) && !gba->rr->isRecording(gba->rr))) {
 		GBASavedataUnmask(&gba->memory.savedata);
 	}
 	GBAMemoryReset(gba);
@@ -713,7 +713,7 @@ void GBAFrameStarted(struct GBA* gba) {
 
 void GBAFrameEnded(struct GBA* gba) {
 	if (gba->rr) {
-		GBARRNextFrame(gba->rr);
+		gba->rr->nextFrame(gba->rr);
 	}
 
 	if (gba->cpu->components[GBA_COMPONENT_CHEAT_DEVICE]) {
diff --git a/src/gba/io.c b/src/gba/io.c
index 6e3361f4b..271aec632 100644
--- a/src/gba/io.c
+++ b/src/gba/io.c
@@ -583,12 +583,12 @@ uint16_t GBAIORead(struct GBA* gba, uint32_t address) {
 		break;
 
 	case REG_KEYINPUT:
-		if (GBARRIsPlaying(gba->rr)) {
-			return 0x3FF ^ GBARRQueryInput(gba->rr);
+		if (gba->rr && gba->rr->isPlaying(gba->rr)) {
+			return 0x3FF ^ gba->rr->queryInput(gba->rr);
 		} else if (gba->keySource) {
 			uint16_t input = *gba->keySource;
-			if (GBARRIsRecording(gba->rr)) {
-				GBARRLogInput(gba->rr, input);
+			if (gba->rr && gba->rr->isRecording(gba->rr)) {
+				gba->rr->logInput(gba->rr, input);
 			}
 			return 0x3FF ^ input;
 		}
diff --git a/src/gba/rr/mgm.c b/src/gba/rr/mgm.c
new file mode 100644
index 000000000..bc487a7b2
--- /dev/null
+++ b/src/gba/rr/mgm.c
@@ -0,0 +1,583 @@
+/* Copyright (c) 2013-2015 Jeffrey Pfau
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+#include "mgm.h"
+
+#include "gba/gba.h"
+#include "gba/serialize.h"
+#include "util/vfs.h"
+
+#define BINARY_EXT ".mgm"
+#define BINARY_MAGIC "GBAb"
+#define METADATA_FILENAME "metadata" BINARY_EXT
+
+enum {
+	INVALID_INPUT = 0x8000
+};
+
+static bool GBAMGMStartPlaying(struct GBARRContext*, bool autorecord);
+static void GBAMGMStopPlaying(struct GBARRContext*);
+static bool GBAMGMStartRecording(struct GBARRContext*);
+static void GBAMGMStopRecording(struct GBARRContext*);
+
+static bool GBAMGMIsPlaying(const struct GBARRContext*);
+static bool GBAMGMIsRecording(const struct GBARRContext*);
+
+static void GBAMGMNextFrame(struct GBARRContext*);
+static void GBAMGMLogInput(struct GBARRContext*, uint16_t input);
+static uint16_t GBAMGMQueryInput(struct GBARRContext*);
+
+static void GBAMGMStateSaved(struct GBARRContext* rr, struct GBASerializedState* state);
+static void GBAMGMStateLoaded(struct GBARRContext* rr, const struct GBASerializedState* state);
+
+static bool _loadStream(struct GBAMGMContext*, uint32_t streamId);
+static bool _incrementStream(struct GBAMGMContext*, bool recursive);
+static bool _finishSegment(struct GBAMGMContext*);
+static bool _skipSegment(struct GBAMGMContext*);
+static bool _markRerecord(struct GBAMGMContext*);
+
+static bool _emitMagic(struct GBAMGMContext*, struct VFile* vf);
+static bool _verifyMagic(struct GBAMGMContext*, struct VFile* vf);
+static enum GBAMGMTag _readTag(struct GBAMGMContext*, struct VFile* vf);
+static bool _seekTag(struct GBAMGMContext*, struct VFile* vf, enum GBAMGMTag tag);
+static bool _emitTag(struct GBAMGMContext*, struct VFile* vf, uint8_t tag);
+static bool _emitEnd(struct GBAMGMContext*, struct VFile* vf);
+
+static bool _parseMetadata(struct GBAMGMContext*, struct VFile* vf);
+
+static bool _markStreamNext(struct GBAMGMContext*, uint32_t newStreamId, bool recursive);
+static void _streamEndReached(struct GBAMGMContext*);
+
+static struct VFile* GBAMGMOpenSavedata(struct GBARRContext*, int flags);
+static struct VFile* GBAMGMOpenSavestate(struct GBARRContext*, int flags);
+
+void GBAMGMContextCreate(struct GBAMGMContext* mgm) {
+	memset(mgm, 0, sizeof(*mgm));
+
+	mgm->d.startPlaying = GBAMGMStartPlaying;
+	mgm->d.stopPlaying = GBAMGMStopPlaying;
+	mgm->d.startRecording = GBAMGMStartRecording;
+	mgm->d.stopRecording = GBAMGMStopRecording;
+
+	mgm->d.isPlaying = GBAMGMIsPlaying;
+	mgm->d.isRecording = GBAMGMIsRecording;
+
+	mgm->d.nextFrame = GBAMGMNextFrame;
+	mgm->d.logInput = GBAMGMLogInput;
+	mgm->d.queryInput = GBAMGMQueryInput;
+
+	mgm->d.stateSaved = GBAMGMStateSaved;
+	mgm->d.stateLoaded = GBAMGMStateLoaded;
+
+	mgm->d.openSavedata = GBAMGMOpenSavedata;
+	mgm->d.openSavestate = GBAMGMOpenSavestate;
+}
+
+void GBAMGMContextDestroy(struct GBAMGMContext* mgm) {
+	if (mgm->d.isPlaying(&mgm->d)) {
+		mgm->d.stopPlaying(&mgm->d);
+	}
+	if (mgm->d.isRecording(&mgm->d)) {
+		mgm->d.stopRecording(&mgm->d);
+	}
+	if (mgm->metadataFile) {
+		mgm->metadataFile->close(mgm->metadataFile);
+	}
+	if (mgm->d.savedata) {
+		mgm->d.savedata->close(mgm->d.savedata);
+		mgm->d.savedata = 0;
+	}
+}
+
+bool GBAMGMSetStream(struct GBAMGMContext* mgm, struct VDir* stream) {
+	if (mgm->movieStream && !mgm->movieStream->close(mgm->movieStream)) {
+		return false;
+	}
+
+	if (mgm->metadataFile && !mgm->metadataFile->close(mgm->metadataFile)) {
+		return false;
+	}
+
+	mgm->streamDir = stream;
+	mgm->metadataFile = mgm->streamDir->openFile(mgm->streamDir, METADATA_FILENAME, O_CREAT | O_RDWR);
+	mgm->currentInput = INVALID_INPUT;
+	if (!_parseMetadata(mgm, mgm->metadataFile)) {
+		mgm->metadataFile->close(mgm->metadataFile);
+		mgm->metadataFile = 0;
+		mgm->maxStreamId = 0;
+	}
+	mgm->streamId = 1;
+	mgm->movieStream = 0;
+	return true;
+}
+
+bool GBAMGMCreateStream(struct GBAMGMContext* mgm, enum GBARRInitFrom initFrom) {
+	if (mgm->metadataFile) {
+		mgm->metadataFile->truncate(mgm->metadataFile, 0);
+	} else {
+		mgm->metadataFile = mgm->streamDir->openFile(mgm->streamDir, METADATA_FILENAME, O_CREAT | O_TRUNC | O_RDWR);
+	}
+	_emitMagic(mgm, mgm->metadataFile);
+
+	mgm->d.initFrom = initFrom;
+	mgm->initFromOffset = mgm->metadataFile->seek(mgm->metadataFile, 0, SEEK_CUR);
+	_emitTag(mgm, mgm->metadataFile, TAG_INIT | initFrom);
+
+	mgm->streamId = 0;
+	mgm->maxStreamId = 0;
+	_emitTag(mgm, mgm->metadataFile, TAG_MAX_STREAM);
+	mgm->maxStreamIdOffset = mgm->metadataFile->seek(mgm->metadataFile, 0, SEEK_CUR);
+	mgm->metadataFile->write(mgm->metadataFile, &mgm->maxStreamId, sizeof(mgm->maxStreamId));
+
+	mgm->d.rrCount = 0;
+	_emitTag(mgm, mgm->metadataFile, TAG_RR_COUNT);
+	mgm->rrCountOffset = mgm->metadataFile->seek(mgm->metadataFile, 0, SEEK_CUR);
+	mgm->metadataFile->write(mgm->metadataFile, &mgm->d.rrCount, sizeof(mgm->d.rrCount));
+	return true;
+}
+
+bool _loadStream(struct GBAMGMContext* mgm, uint32_t streamId) {
+	if (mgm->movieStream && !mgm->movieStream->close(mgm->movieStream)) {
+		return false;
+	}
+	mgm->movieStream = 0;
+	mgm->streamId = streamId;
+	mgm->currentInput = INVALID_INPUT;
+	char buffer[14];
+	snprintf(buffer, sizeof(buffer), "%u" BINARY_EXT, streamId);
+	if (mgm->d.isRecording(&mgm->d)) {
+		int flags = O_CREAT | O_RDWR;
+		if (streamId > mgm->maxStreamId) {
+			flags |= O_TRUNC;
+		}
+		mgm->movieStream = mgm->streamDir->openFile(mgm->streamDir, buffer, flags);
+	} else if (mgm->d.isPlaying(&mgm->d)) {
+		mgm->movieStream = mgm->streamDir->openFile(mgm->streamDir, buffer, O_RDONLY);
+		mgm->peekedTag = TAG_INVALID;
+		if (!mgm->movieStream || !_verifyMagic(mgm, mgm->movieStream) || !_seekTag(mgm, mgm->movieStream, TAG_BEGIN)) {
+			mgm->d.stopPlaying(&mgm->d);
+		}
+	}
+	GBALog(0, GBA_LOG_DEBUG, "[RR] Loading segment: %u", streamId);
+	mgm->d.frames = 0;
+	mgm->d.lagFrames = 0;
+	return true;
+}
+
+bool _incrementStream(struct GBAMGMContext* mgm, bool recursive) {
+	uint32_t newStreamId = mgm->maxStreamId + 1;
+	uint32_t oldStreamId = mgm->streamId;
+	if (mgm->d.isRecording(&mgm->d) && mgm->movieStream) {
+		if (!_markStreamNext(mgm, newStreamId, recursive)) {
+			return false;
+		}
+	}
+	if (!_loadStream(mgm, newStreamId)) {
+		return false;
+	}
+	GBALog(0, GBA_LOG_DEBUG, "[RR] New segment: %u", newStreamId);
+	_emitMagic(mgm, mgm->movieStream);
+	mgm->maxStreamId = newStreamId;
+	_emitTag(mgm, mgm->movieStream, TAG_PREVIOUSLY);
+	mgm->movieStream->write(mgm->movieStream, &oldStreamId, sizeof(oldStreamId));
+	_emitTag(mgm, mgm->movieStream, TAG_BEGIN);
+
+	mgm->metadataFile->seek(mgm->metadataFile, mgm->maxStreamIdOffset, SEEK_SET);
+	mgm->metadataFile->write(mgm->metadataFile, &mgm->maxStreamId, sizeof(mgm->maxStreamId));
+	mgm->previously = oldStreamId;
+	return true;
+}
+
+bool GBAMGMStartPlaying(struct GBARRContext* rr, bool autorecord) {
+	if (rr->isRecording(rr) || rr->isPlaying(rr)) {
+		return false;
+	}
+
+	struct GBAMGMContext* mgm = (struct GBAMGMContext*) rr;
+	mgm->isPlaying = true;
+	if (!_loadStream(mgm, 1)) {
+		mgm->isPlaying = false;
+		return false;
+	}
+	mgm->autorecord = autorecord;
+	return true;
+}
+
+void GBAMGMStopPlaying(struct GBARRContext* rr) {
+	if (!rr->isPlaying(rr)) {
+		return;
+	}
+
+	struct GBAMGMContext* mgm = (struct GBAMGMContext*) rr;
+	mgm->isPlaying = false;
+	if (mgm->movieStream) {
+		mgm->movieStream->close(mgm->movieStream);
+		mgm->movieStream = 0;
+	}
+}
+
+bool GBAMGMStartRecording(struct GBARRContext* rr) {
+	if (rr->isRecording(rr) || rr->isPlaying(rr)) {
+		return false;
+	}
+
+	struct GBAMGMContext* mgm = (struct GBAMGMContext*) rr;
+	if (!mgm->maxStreamIdOffset) {
+		_emitTag(mgm, mgm->metadataFile, TAG_MAX_STREAM);
+		mgm->maxStreamIdOffset = mgm->metadataFile->seek(mgm->metadataFile, 0, SEEK_CUR);
+		mgm->metadataFile->write(mgm->metadataFile, &mgm->maxStreamId, sizeof(mgm->maxStreamId));
+	}
+
+	mgm->isRecording = true;
+	return _incrementStream(mgm, false);
+}
+
+void GBAMGMStopRecording(struct GBARRContext* rr) {
+	if (!rr->isRecording(rr)) {
+		return;
+	}
+
+	struct GBAMGMContext* mgm = (struct GBAMGMContext*) rr;
+	mgm->isRecording = false;
+	if (mgm->movieStream) {
+		_emitEnd(mgm, mgm->movieStream);
+		mgm->movieStream->close(mgm->movieStream);
+		mgm->movieStream = 0;
+	}
+}
+
+bool GBAMGMIsPlaying(const struct GBARRContext* rr) {
+	const struct GBAMGMContext* mgm = (const struct GBAMGMContext*) rr;
+	return mgm->isPlaying;
+}
+
+bool GBAMGMIsRecording(const struct GBARRContext* rr) {
+	const struct GBAMGMContext* mgm = (const struct GBAMGMContext*) rr;
+	return mgm->isRecording;
+}
+
+void GBAMGMNextFrame(struct GBARRContext* rr) {
+	if (!rr->isRecording(rr) && !rr->isPlaying(rr)) {
+		return;
+	}
+
+	struct GBAMGMContext* mgm = (struct GBAMGMContext*) rr;
+	if (rr->isPlaying(rr)) {
+		while (mgm->peekedTag == TAG_INPUT) {
+			_readTag(mgm, mgm->movieStream);
+			GBALog(0, GBA_LOG_WARN, "[RR] Desync detected!");
+		}
+		if (mgm->peekedTag == TAG_LAG) {
+			GBALog(0, GBA_LOG_DEBUG, "[RR] Lag frame marked in stream");
+			if (mgm->inputThisFrame) {
+				GBALog(0, GBA_LOG_WARN, "[RR] Lag frame in stream does not match movie");
+			}
+		}
+	}
+
+	++mgm->d.frames;
+	GBALog(0, GBA_LOG_DEBUG, "[RR] Frame: %u", mgm->d.frames);
+	if (!mgm->inputThisFrame) {
+		++mgm->d.lagFrames;
+		GBALog(0, GBA_LOG_DEBUG, "[RR] Lag frame: %u", mgm->d.lagFrames);
+	}
+
+	if (rr->isRecording(rr)) {
+		if (!mgm->inputThisFrame) {
+			_emitTag(mgm, mgm->movieStream, TAG_LAG);
+		}
+		_emitTag(mgm, mgm->movieStream, TAG_FRAME);
+		mgm->inputThisFrame = false;
+	} else {
+		if (!_seekTag(mgm, mgm->movieStream, TAG_FRAME)) {
+			_streamEndReached(mgm);
+		}
+	}
+}
+
+void GBAMGMLogInput(struct GBARRContext* rr, uint16_t keys) {
+	if (!rr->isRecording(rr)) {
+		return;
+	}
+
+	struct GBAMGMContext* mgm = (struct GBAMGMContext*) rr;
+	if (keys != mgm->currentInput) {
+		_emitTag(mgm, mgm->movieStream, TAG_INPUT);
+		mgm->movieStream->write(mgm->movieStream, &keys, sizeof(keys));
+		mgm->currentInput = keys;
+	}
+	GBALog(0, GBA_LOG_DEBUG, "[RR] Input log: %03X", mgm->currentInput);
+	mgm->inputThisFrame = true;
+}
+
+uint16_t GBAMGMQueryInput(struct GBARRContext* rr) {
+	if (!rr->isPlaying(rr)) {
+		return 0;
+	}
+
+	struct GBAMGMContext* mgm = (struct GBAMGMContext*) rr;
+	if (mgm->peekedTag == TAG_INPUT) {
+		_readTag(mgm, mgm->movieStream);
+	}
+	mgm->inputThisFrame = true;
+	if (mgm->currentInput == INVALID_INPUT) {
+		GBALog(0, GBA_LOG_WARN, "[RR] Stream did not specify input");
+	}
+	GBALog(0, GBA_LOG_DEBUG, "[RR] Input replay: %03X", mgm->currentInput);
+	return mgm->currentInput;
+}
+
+void GBAMGMStateSaved(struct GBARRContext* rr, struct GBASerializedState* state) {
+	struct GBAMGMContext* mgm = (struct GBAMGMContext*) rr;
+	if (rr->isRecording(rr)) {
+		state->associatedStreamId = mgm->streamId;
+		_finishSegment(mgm);
+	}
+}
+
+void GBAMGMStateLoaded(struct GBARRContext* rr, const struct GBASerializedState* state) {
+	struct GBAMGMContext* mgm = (struct GBAMGMContext*) rr;
+	if (rr->isRecording(rr)) {
+		if (state->associatedStreamId != mgm->streamId) {
+			_loadStream(mgm, state->associatedStreamId);
+			_incrementStream(mgm, true);
+		} else {
+			_finishSegment(mgm);
+		}
+		_markRerecord(mgm);
+	} else if (rr->isPlaying(rr)) {
+		_loadStream(mgm, state->associatedStreamId);
+		_skipSegment(mgm);
+	}
+}
+
+bool _finishSegment(struct GBAMGMContext* mgm) {
+	if (mgm->movieStream) {
+		if (!_emitEnd(mgm, mgm->movieStream)) {
+			return false;
+		}
+	}
+	return _incrementStream(mgm, false);
+}
+
+bool _skipSegment(struct GBAMGMContext* mgm) {
+	mgm->nextTime = 0;
+	while (_readTag(mgm, mgm->movieStream) != TAG_EOF);
+	if (!mgm->nextTime || !_loadStream(mgm, mgm->nextTime)) {
+		_streamEndReached(mgm);
+		return false;
+	}
+	return true;
+}
+
+bool _markRerecord(struct GBAMGMContext* mgm) {
+	++mgm->d.rrCount;
+	mgm->metadataFile->seek(mgm->metadataFile, mgm->rrCountOffset, SEEK_SET);
+	mgm->metadataFile->write(mgm->metadataFile, &mgm->d.rrCount, sizeof(mgm->d.rrCount));
+	return true;
+}
+
+bool _emitMagic(struct GBAMGMContext* mgm, struct VFile* vf) {
+	UNUSED(mgm);
+	return vf->write(vf, BINARY_MAGIC, 4) == 4;
+}
+
+bool _verifyMagic(struct GBAMGMContext* mgm, struct VFile* vf) {
+	UNUSED(mgm);
+	char buffer[4];
+	if (vf->read(vf, buffer, sizeof(buffer)) != sizeof(buffer)) {
+		return false;
+	}
+	if (memcmp(buffer, BINARY_MAGIC, sizeof(buffer)) != 0) {
+		return false;
+	}
+	return true;
+}
+
+enum GBAMGMTag _readTag(struct GBAMGMContext* mgm, struct VFile* vf) {
+	if (!mgm || !vf) {
+		return TAG_EOF;
+	}
+
+	enum GBAMGMTag tag = mgm->peekedTag;
+	switch (tag) {
+	case TAG_INPUT:
+		vf->read(vf, &mgm->currentInput, sizeof(uint16_t));
+		break;
+	case TAG_PREVIOUSLY:
+		vf->read(vf, &mgm->previously, sizeof(mgm->previously));
+		break;
+	case TAG_NEXT_TIME:
+		vf->read(vf, &mgm->nextTime, sizeof(mgm->nextTime));
+		break;
+	case TAG_MAX_STREAM:
+		vf->read(vf, &mgm->maxStreamId, sizeof(mgm->maxStreamId));
+		break;
+	case TAG_FRAME_COUNT:
+		vf->read(vf, &mgm->d.frames, sizeof(mgm->d.frames));
+		break;
+	case TAG_LAG_COUNT:
+		vf->read(vf, &mgm->d.lagFrames, sizeof(mgm->d.lagFrames));
+		break;
+	case TAG_RR_COUNT:
+		vf->read(vf, &mgm->d.rrCount, sizeof(mgm->d.rrCount));
+		break;
+
+	case TAG_INIT_EX_NIHILO:
+		mgm->d.initFrom = INIT_EX_NIHILO;
+		break;
+	case TAG_INIT_FROM_SAVEGAME:
+		mgm->d.initFrom = INIT_FROM_SAVEGAME;
+		break;
+	case TAG_INIT_FROM_SAVESTATE:
+		mgm->d.initFrom = INIT_FROM_SAVESTATE;
+		break;
+	case TAG_INIT_FROM_BOTH:
+		mgm->d.initFrom = INIT_FROM_BOTH;
+		break;
+
+	// To be spec'd
+	case TAG_AUTHOR:
+	case TAG_COMMENT:
+		break;
+
+	// Empty markers
+	case TAG_FRAME:
+	case TAG_LAG:
+	case TAG_BEGIN:
+	case TAG_END:
+	case TAG_INVALID:
+	case TAG_EOF:
+		break;
+	}
+
+	uint8_t tagBuffer;
+	if (vf->read(vf, &tagBuffer, 1) != 1) {
+		mgm->peekedTag = TAG_EOF;
+	} else {
+		mgm->peekedTag = tagBuffer;
+	}
+
+	if (mgm->peekedTag == TAG_END) {
+		_skipSegment(mgm);
+	}
+	return tag;
+}
+
+bool _seekTag(struct GBAMGMContext* mgm, struct VFile* vf, enum GBAMGMTag tag) {
+	enum GBAMGMTag readTag;
+	while ((readTag = _readTag(mgm, vf)) != tag) {
+		if (readTag == TAG_EOF) {
+			return false;
+		}
+	}
+	return true;
+}
+
+bool _emitTag(struct GBAMGMContext* mgm, struct VFile* vf, uint8_t tag) {
+	UNUSED(mgm);
+	return vf->write(vf, &tag, sizeof(tag)) == sizeof(tag);
+}
+
+bool _parseMetadata(struct GBAMGMContext* mgm, struct VFile* vf) {
+	if (!_verifyMagic(mgm, vf)) {
+		return false;
+	}
+	while (_readTag(mgm, vf) != TAG_EOF) {
+		switch (mgm->peekedTag) {
+		case TAG_MAX_STREAM:
+			mgm->maxStreamIdOffset = vf->seek(vf, 0, SEEK_CUR);
+			break;
+		case TAG_INIT_EX_NIHILO:
+		case TAG_INIT_FROM_SAVEGAME:
+		case TAG_INIT_FROM_SAVESTATE:
+		case TAG_INIT_FROM_BOTH:
+			mgm->initFromOffset = vf->seek(vf, 0, SEEK_CUR);
+			break;
+		case TAG_RR_COUNT:
+			mgm->rrCountOffset = vf->seek(vf, 0, SEEK_CUR);
+			break;
+		default:
+			break;
+		}
+	}
+	return true;
+}
+
+bool _emitEnd(struct GBAMGMContext* mgm, struct VFile* vf) {
+	// TODO: Error check
+	_emitTag(mgm, vf, TAG_END);
+	_emitTag(mgm, vf, TAG_FRAME_COUNT);
+	vf->write(vf, &mgm->d.frames, sizeof(mgm->d.frames));
+	_emitTag(mgm, vf, TAG_LAG_COUNT);
+	vf->write(vf, &mgm->d.lagFrames, sizeof(mgm->d.lagFrames));
+	_emitTag(mgm, vf, TAG_NEXT_TIME);
+
+	uint32_t newStreamId = 0;
+	vf->write(vf, &newStreamId, sizeof(newStreamId));
+	return true;
+}
+
+bool _markStreamNext(struct GBAMGMContext* mgm, uint32_t newStreamId, bool recursive) {
+	if (mgm->movieStream->seek(mgm->movieStream, -sizeof(newStreamId) - 1, SEEK_END) < 0) {
+		return false;
+	}
+
+	uint8_t tagBuffer;
+	if (mgm->movieStream->read(mgm->movieStream, &tagBuffer, 1) != 1) {
+		return false;
+	}
+	if (tagBuffer != TAG_NEXT_TIME) {
+		return false;
+	}
+	if (mgm->movieStream->write(mgm->movieStream, &newStreamId, sizeof(newStreamId)) != sizeof(newStreamId)) {
+		return false;
+	}
+	if (recursive) {
+		if (mgm->movieStream->seek(mgm->movieStream, 0, SEEK_SET) < 0) {
+			return false;
+		}
+		if (!_verifyMagic(mgm, mgm->movieStream)) {
+			return false;
+		}
+		_readTag(mgm, mgm->movieStream);
+		if (_readTag(mgm, mgm->movieStream) != TAG_PREVIOUSLY) {
+			return false;
+		}
+		if (mgm->previously == 0) {
+			return true;
+		}
+		uint32_t currentStreamId = mgm->streamId;
+		if (!_loadStream(mgm, mgm->previously)) {
+			return false;
+		}
+		return _markStreamNext(mgm, currentStreamId, mgm->previously);
+	}
+	return true;
+}
+
+void _streamEndReached(struct GBAMGMContext* mgm) {
+	if (!mgm->d.isPlaying(&mgm->d)) {
+		return;
+	}
+
+	uint32_t endStreamId = mgm->streamId;
+	mgm->d.stopPlaying(&mgm->d);
+	if (mgm->autorecord) {
+		mgm->isRecording = true;
+		_loadStream(mgm, endStreamId);
+		_incrementStream(mgm, false);
+	}
+}
+
+struct VFile* GBAMGMOpenSavedata(struct GBARRContext* rr, int flags) {
+	struct GBAMGMContext* mgm = (struct GBAMGMContext*) rr;
+	return mgm->streamDir->openFile(mgm->streamDir, "movie.sav", flags);
+}
+
+struct VFile* GBAMGMOpenSavestate(struct GBARRContext* rr, int flags) {
+	struct GBAMGMContext* mgm = (struct GBAMGMContext*) rr;
+	return mgm->streamDir->openFile(mgm->streamDir, "movie.ssm", flags);
+}
diff --git a/src/gba/rr/mgm.h b/src/gba/rr/mgm.h
new file mode 100644
index 000000000..3b08655ca
--- /dev/null
+++ b/src/gba/rr/mgm.h
@@ -0,0 +1,83 @@
+/* Copyright (c) 2013-2015 Jeffrey Pfau
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+#ifndef RR_MGM_H
+#define RR_MGM_H
+
+#include "util/common.h"
+
+#include "gba/supervisor/rr.h"
+
+struct GBA;
+struct VDir;
+struct VFile;
+
+enum GBAMGMTag {
+	// Playback tags
+	TAG_INVALID = 0x00,
+	TAG_INPUT = 0x01,
+	TAG_FRAME = 0x02,
+	TAG_LAG = 0x03,
+
+	// Stream chunking tags
+	TAG_BEGIN = 0x10,
+	TAG_END = 0x11,
+	TAG_PREVIOUSLY = 0x12,
+	TAG_NEXT_TIME = 0x13,
+	TAG_MAX_STREAM = 0x14,
+
+	// Recording information tags
+	TAG_FRAME_COUNT = 0x20,
+	TAG_LAG_COUNT = 0x21,
+	TAG_RR_COUNT = 0x22,
+	TAG_INIT = 0x24,
+	TAG_INIT_EX_NIHILO = 0x24 | INIT_EX_NIHILO,
+	TAG_INIT_FROM_SAVEGAME = 0x24 | INIT_FROM_SAVEGAME,
+	TAG_INIT_FROM_SAVESTATE = 0x24 | INIT_FROM_SAVESTATE,
+	TAG_INIT_FROM_BOTH = 0x24 | INIT_FROM_BOTH,
+
+	// User metadata tags
+	TAG_AUTHOR = 0x30,
+	TAG_COMMENT = 0x31,
+
+	TAG_EOF = INT_MAX
+};
+
+struct GBAMGMContext {
+	struct GBARRContext d;
+
+	// Playback state
+	bool isPlaying;
+	bool autorecord;
+
+	// Recording state
+	bool isRecording;
+	bool inputThisFrame;
+
+	// Metadata
+	uint32_t streamId;
+
+	uint32_t maxStreamId;
+	off_t maxStreamIdOffset;
+	off_t initFromOffset;
+	off_t rrCountOffset;
+
+	// Streaming state
+	struct VDir* streamDir;
+	struct VFile* metadataFile;
+	struct VFile* movieStream;
+	uint16_t currentInput;
+	enum GBAMGMTag peekedTag;
+	uint32_t nextTime;
+	uint32_t previously;
+};
+
+void GBAMGMContextCreate(struct GBAMGMContext*);
+void GBAMGMContextDestroy(struct GBAMGMContext*);
+
+bool GBAMGMSetStream(struct GBAMGMContext* mgm, struct VDir* stream);
+bool GBAMGMCreateStream(struct GBAMGMContext* mgm, enum GBARRInitFrom initFrom);
+
+#endif
diff --git a/src/gba/serialize.c b/src/gba/serialize.c
index 56914f3dc..93a873c6e 100644
--- a/src/gba/serialize.c
+++ b/src/gba/serialize.c
@@ -49,11 +49,9 @@ void GBASerialize(struct GBA* gba, struct GBASerializedState* state) {
 	GBAVideoSerialize(&gba->video, state);
 	GBAAudioSerialize(&gba->audio, state);
 
-	if (GBARRIsRecording(gba->rr)) {
-		state->associatedStreamId = gba->rr->streamId;
-		GBARRFinishSegment(gba->rr);
-	} else {
-		state->associatedStreamId = 0;
+	state->associatedStreamId = 0;
+	if (gba->rr) {
+		gba->rr->stateSaved(gba->rr, state);
 	}
 }
 
@@ -114,17 +112,8 @@ void GBADeserialize(struct GBA* gba, struct GBASerializedState* state) {
 	GBAVideoDeserialize(&gba->video, state);
 	GBAAudioDeserialize(&gba->audio, state);
 
-	if (GBARRIsRecording(gba->rr)) {
-		if (state->associatedStreamId != gba->rr->streamId) {
-			GBARRLoadStream(gba->rr, state->associatedStreamId);
-			GBARRIncrementStream(gba->rr, true);
-		} else {
-			GBARRFinishSegment(gba->rr);
-		}
-		GBARRMarkRerecord(gba->rr);
-	} else if (GBARRIsPlaying(gba->rr)) {
-		GBARRLoadStream(gba->rr, state->associatedStreamId);
-		GBARRSkipSegment(gba->rr);
+	if (gba->rr) {
+		gba->rr->stateLoaded(gba->rr, state);
 	}
 }
 
diff --git a/src/gba/supervisor/rr.c b/src/gba/supervisor/rr.c
index 4e88bbdd4..06ffc07e0 100644
--- a/src/gba/supervisor/rr.c
+++ b/src/gba/supervisor/rr.c
@@ -5,63 +5,8 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include "rr.h"
 
-#include "gba/gba.h"
-#include "gba/serialize.h"
 #include "util/vfs.h"
 
-#define BINARY_EXT ".dat"
-#define BINARY_MAGIC "GBAb"
-#define METADATA_FILENAME "metadata" BINARY_EXT
-
-enum {
-	INVALID_INPUT = 0x8000
-};
-
-static bool _emitMagic(struct GBARRContext* rr, struct VFile* vf);
-static bool _verifyMagic(struct GBARRContext* rr, struct VFile* vf);
-static enum GBARRTag _readTag(struct GBARRContext* rr, struct VFile* vf);
-static bool _seekTag(struct GBARRContext* rr, struct VFile* vf, enum GBARRTag tag);
-static bool _emitTag(struct GBARRContext* rr, struct VFile* vf, uint8_t tag);
-static bool _emitEnd(struct GBARRContext* rr, struct VFile* vf);
-
-static bool _parseMetadata(struct GBARRContext* rr, struct VFile* vf);
-
-static bool _markStreamNext(struct GBARRContext* rr, uint32_t newStreamId, bool recursive);
-static void _streamEndReached(struct GBARRContext* rr);
-
-static struct VFile* _openSavedata(struct GBARRContext* rr, int flags);
-static struct VFile* _openSavestate(struct GBARRContext* rr, int flags);
-
-void GBARRContextCreate(struct GBA* gba) {
-	if (gba->rr) {
-		return;
-	}
-
-	gba->rr = calloc(1, sizeof(*gba->rr));
-}
-
-void GBARRContextDestroy(struct GBA* gba) {
-	if (!gba->rr) {
-		return;
-	}
-
-	if (GBARRIsPlaying(gba->rr)) {
-		GBARRStopPlaying(gba->rr);
-	}
-	if (GBARRIsRecording(gba->rr)) {
-		GBARRStopRecording(gba->rr);
-	}
-	if (gba->rr->metadataFile) {
-		gba->rr->metadataFile->close(gba->rr->metadataFile);
-	}
-	if (gba->rr->savedata) {
-		gba->rr->savedata->close(gba->rr->savedata);
-	}
-
-	free(gba->rr);
-	gba->rr = 0;
-}
-
 void GBARRSaveState(struct GBA* gba) {
 	if (!gba || !gba->rr) {
 		return;
@@ -71,17 +16,17 @@ void GBARRSaveState(struct GBA* gba) {
 		if (gba->rr->savedata) {
 			gba->rr->savedata->close(gba->rr->savedata);
 		}
-		gba->rr->savedata = _openSavedata(gba->rr, O_TRUNC | O_CREAT | O_WRONLY);
+		gba->rr->savedata = gba->rr->openSavedata(gba->rr, O_TRUNC | O_CREAT | O_WRONLY);
 		GBASavedataClone(&gba->memory.savedata, gba->rr->savedata);
 		gba->rr->savedata->close(gba->rr->savedata);
-		gba->rr->savedata = _openSavedata(gba->rr, O_RDONLY);
+		gba->rr->savedata = gba->rr->openSavedata(gba->rr, O_RDONLY);
 		GBASavedataMask(&gba->memory.savedata, gba->rr->savedata);
 	} else {
 		GBASavedataMask(&gba->memory.savedata, 0);
 	}
 
 	if (gba->rr->initFrom & INIT_FROM_SAVESTATE) {
-		struct VFile* vf = _openSavestate(gba->rr, O_TRUNC | O_CREAT | O_RDWR);
+		struct VFile* vf = gba->rr->openSavestate(gba->rr, O_TRUNC | O_CREAT | O_RDWR);
 		GBASaveStateNamed(gba, vf, false);
 		vf->close(vf);
 	} else {
@@ -98,475 +43,17 @@ void GBARRLoadState(struct GBA* gba) {
 		if (gba->rr->savedata) {
 			gba->rr->savedata->close(gba->rr->savedata);
 		}
-		gba->rr->savedata = _openSavedata(gba->rr, O_RDONLY);
+		gba->rr->savedata = gba->rr->openSavedata(gba->rr, O_RDONLY);
 		GBASavedataMask(&gba->memory.savedata, gba->rr->savedata);
 	} else {
 		GBASavedataMask(&gba->memory.savedata, 0);
 	}
 
 	if (gba->rr->initFrom & INIT_FROM_SAVESTATE) {
-		struct VFile* vf = _openSavestate(gba->rr, O_RDONLY);
+		struct VFile* vf = gba->rr->openSavestate(gba->rr, O_RDONLY);
 		GBALoadStateNamed(gba, vf);
 		vf->close(vf);
 	} else {
 		ARMReset(gba->cpu);
 	}
 }
-
-bool GBARRInitStream(struct GBARRContext* rr, struct VDir* stream) {
-	if (rr->movieStream && !rr->movieStream->close(rr->movieStream)) {
-		return false;
-	}
-
-	if (rr->metadataFile && !rr->metadataFile->close(rr->metadataFile)) {
-		return false;
-	}
-
-	rr->streamDir = stream;
-	rr->metadataFile = rr->streamDir->openFile(rr->streamDir, METADATA_FILENAME, O_CREAT | O_RDWR);
-	rr->currentInput = INVALID_INPUT;
-	if (!_parseMetadata(rr, rr->metadataFile)) {
-		rr->metadataFile->close(rr->metadataFile);
-		rr->metadataFile = 0;
-		rr->maxStreamId = 0;
-	}
-	rr->streamId = 1;
-	rr->movieStream = 0;
-	return true;
-}
-
-bool GBARRReinitStream(struct GBARRContext* rr, enum GBARRInitFrom initFrom) {
-	if (!rr) {
-		return false;
-	}
-
-	if (rr->metadataFile) {
-		rr->metadataFile->truncate(rr->metadataFile, 0);
-	} else {
-		rr->metadataFile = rr->streamDir->openFile(rr->streamDir, METADATA_FILENAME, O_CREAT | O_TRUNC | O_RDWR);
-	}
-	_emitMagic(rr, rr->metadataFile);
-
-	rr->initFrom = initFrom;
-	rr->initFromOffset = rr->metadataFile->seek(rr->metadataFile, 0, SEEK_CUR);
-	_emitTag(rr, rr->metadataFile, TAG_INIT | initFrom);
-
-	rr->streamId = 0;
-	rr->maxStreamId = 0;
-	_emitTag(rr, rr->metadataFile, TAG_MAX_STREAM);
-	rr->maxStreamIdOffset = rr->metadataFile->seek(rr->metadataFile, 0, SEEK_CUR);
-	rr->metadataFile->write(rr->metadataFile, &rr->maxStreamId, sizeof(rr->maxStreamId));
-
-	rr->rrCount = 0;
-	_emitTag(rr, rr->metadataFile, TAG_RR_COUNT);
-	rr->rrCountOffset = rr->metadataFile->seek(rr->metadataFile, 0, SEEK_CUR);
-	rr->metadataFile->write(rr->metadataFile, &rr->rrCount, sizeof(rr->rrCount));
-	return true;
-}
-
-bool GBARRLoadStream(struct GBARRContext* rr, uint32_t streamId) {
-	if (rr->movieStream && !rr->movieStream->close(rr->movieStream)) {
-		return false;
-	}
-	rr->movieStream = 0;
-	rr->streamId = streamId;
-	rr->currentInput = INVALID_INPUT;
-	char buffer[14];
-	snprintf(buffer, sizeof(buffer), "%u" BINARY_EXT, streamId);
-	if (GBARRIsRecording(rr)) {
-		int flags = O_CREAT | O_RDWR;
-		if (streamId > rr->maxStreamId) {
-			flags |= O_TRUNC;
-		}
-		rr->movieStream = rr->streamDir->openFile(rr->streamDir, buffer, flags);
-	} else if (GBARRIsPlaying(rr)) {
-		rr->movieStream = rr->streamDir->openFile(rr->streamDir, buffer, O_RDONLY);
-		rr->peekedTag = TAG_INVALID;
-		if (!rr->movieStream || !_verifyMagic(rr, rr->movieStream) || !_seekTag(rr, rr->movieStream, TAG_BEGIN)) {
-			GBARRStopPlaying(rr);
-		}
-	}
-	GBALog(0, GBA_LOG_DEBUG, "[RR] Loading segment: %u", streamId);
-	rr->frames = 0;
-	rr->lagFrames = 0;
-	return true;
-}
-
-bool GBARRIncrementStream(struct GBARRContext* rr, bool recursive) {
-	uint32_t newStreamId = rr->maxStreamId + 1;
-	uint32_t oldStreamId = rr->streamId;
-	if (GBARRIsRecording(rr) && rr->movieStream) {
-		if (!_markStreamNext(rr, newStreamId, recursive)) {
-			return false;
-		}
-	}
-	if (!GBARRLoadStream(rr, newStreamId)) {
-		return false;
-	}
-	GBALog(0, GBA_LOG_DEBUG, "[RR] New segment: %u", newStreamId);
-	_emitMagic(rr, rr->movieStream);
-	rr->maxStreamId = newStreamId;
-	_emitTag(rr, rr->movieStream, TAG_PREVIOUSLY);
-	rr->movieStream->write(rr->movieStream, &oldStreamId, sizeof(oldStreamId));
-	_emitTag(rr, rr->movieStream, TAG_BEGIN);
-
-	rr->metadataFile->seek(rr->metadataFile, rr->maxStreamIdOffset, SEEK_SET);
-	rr->metadataFile->write(rr->metadataFile, &rr->maxStreamId, sizeof(rr->maxStreamId));
-	rr->previously = oldStreamId;
-	return true;
-}
-
-bool GBARRStartPlaying(struct GBARRContext* rr, bool autorecord) {
-	if (GBARRIsRecording(rr) || GBARRIsPlaying(rr)) {
-		return false;
-	}
-
-	rr->isPlaying = true;
-	if (!GBARRLoadStream(rr, 1)) {
-		rr->isPlaying = false;
-		return false;
-	}
-	rr->autorecord = autorecord;
-	return true;
-}
-
-void GBARRStopPlaying(struct GBARRContext* rr) {
-	if (!GBARRIsPlaying(rr)) {
-		return;
-	}
-	rr->isPlaying = false;
-	if (rr->movieStream) {
-		rr->movieStream->close(rr->movieStream);
-		rr->movieStream = 0;
-	}
-}
-
-bool GBARRStartRecording(struct GBARRContext* rr) {
-	if (GBARRIsRecording(rr) || GBARRIsPlaying(rr)) {
-		return false;
-	}
-
-	if (!rr->maxStreamIdOffset) {
-		_emitTag(rr, rr->metadataFile, TAG_MAX_STREAM);
-		rr->maxStreamIdOffset = rr->metadataFile->seek(rr->metadataFile, 0, SEEK_CUR);
-		rr->metadataFile->write(rr->metadataFile, &rr->maxStreamId, sizeof(rr->maxStreamId));
-	}
-
-	rr->isRecording = true;
-	return GBARRIncrementStream(rr, false);
-}
-
-void GBARRStopRecording(struct GBARRContext* rr) {
-	if (!GBARRIsRecording(rr)) {
-		return;
-	}
-	rr->isRecording = false;
-	if (rr->movieStream) {
-		_emitEnd(rr, rr->movieStream);
-		rr->movieStream->close(rr->movieStream);
-		rr->movieStream = 0;
-	}
-}
-
-bool GBARRIsPlaying(struct GBARRContext* rr) {
-	return rr && rr->isPlaying;
-}
-
-bool GBARRIsRecording(struct GBARRContext* rr) {
-	return rr && rr->isRecording;
-}
-
-void GBARRNextFrame(struct GBARRContext* rr) {
-	if (!GBARRIsRecording(rr) && !GBARRIsPlaying(rr)) {
-		return;
-	}
-
-	if (GBARRIsPlaying(rr)) {
-		while (rr->peekedTag == TAG_INPUT) {
-			_readTag(rr, rr->movieStream);
-			GBALog(0, GBA_LOG_WARN, "[RR] Desync detected!");
-		}
-		if (rr->peekedTag == TAG_LAG) {
-			GBALog(0, GBA_LOG_DEBUG, "[RR] Lag frame marked in stream");
-			if (rr->inputThisFrame) {
-				GBALog(0, GBA_LOG_WARN, "[RR] Lag frame in stream does not match movie");
-			}
-		}
-	}
-
-	++rr->frames;
-	GBALog(0, GBA_LOG_DEBUG, "[RR] Frame: %u", rr->frames);
-	if (!rr->inputThisFrame) {
-		++rr->lagFrames;
-		GBALog(0, GBA_LOG_DEBUG, "[RR] Lag frame: %u", rr->lagFrames);
-	}
-
-	if (GBARRIsRecording(rr)) {
-		if (!rr->inputThisFrame) {
-			_emitTag(rr, rr->movieStream, TAG_LAG);
-		}
-		_emitTag(rr, rr->movieStream, TAG_FRAME);
-		rr->inputThisFrame = false;
-	} else {
-		if (!_seekTag(rr, rr->movieStream, TAG_FRAME)) {
-			_streamEndReached(rr);
-		}
-	}
-}
-
-void GBARRLogInput(struct GBARRContext* rr, uint16_t keys) {
-	if (!GBARRIsRecording(rr)) {
-		return;
-	}
-
-	if (keys != rr->currentInput) {
-		_emitTag(rr, rr->movieStream, TAG_INPUT);
-		rr->movieStream->write(rr->movieStream, &keys, sizeof(keys));
-		rr->currentInput = keys;
-	}
-	GBALog(0, GBA_LOG_DEBUG, "[RR] Input log: %03X", rr->currentInput);
-	rr->inputThisFrame = true;
-}
-
-uint16_t GBARRQueryInput(struct GBARRContext* rr) {
-	if (!GBARRIsPlaying(rr)) {
-		return 0;
-	}
-
-	if (rr->peekedTag == TAG_INPUT) {
-		_readTag(rr, rr->movieStream);
-	}
-	rr->inputThisFrame = true;
-	if (rr->currentInput == INVALID_INPUT) {
-		GBALog(0, GBA_LOG_WARN, "[RR] Stream did not specify input");
-	}
-	GBALog(0, GBA_LOG_DEBUG, "[RR] Input replay: %03X", rr->currentInput);
-	return rr->currentInput;
-}
-
-bool GBARRFinishSegment(struct GBARRContext* rr) {
-	if (rr->movieStream) {
-		if (!_emitEnd(rr, rr->movieStream)) {
-			return false;
-		}
-	}
-	return GBARRIncrementStream(rr, false);
-}
-
-bool GBARRSkipSegment(struct GBARRContext* rr) {
-	rr->nextTime = 0;
-	while (_readTag(rr, rr->movieStream) != TAG_EOF);
-	if (!rr->nextTime || !GBARRLoadStream(rr, rr->nextTime)) {
-		_streamEndReached(rr);
-		return false;
-	}
-	return true;
-}
-
-bool GBARRMarkRerecord(struct GBARRContext* rr) {
-	++rr->rrCount;
-	rr->metadataFile->seek(rr->metadataFile, rr->rrCountOffset, SEEK_SET);
-	rr->metadataFile->write(rr->metadataFile, &rr->rrCount, sizeof(rr->rrCount));
-	return true;
-}
-
-bool _emitMagic(struct GBARRContext* rr, struct VFile* vf) {
-	UNUSED(rr);
-	return vf->write(vf, BINARY_MAGIC, 4) == 4;
-}
-
-bool _verifyMagic(struct GBARRContext* rr, struct VFile* vf) {
-	UNUSED(rr);
-	char buffer[4];
-	if (vf->read(vf, buffer, sizeof(buffer)) != sizeof(buffer)) {
-		return false;
-	}
-	if (memcmp(buffer, BINARY_MAGIC, sizeof(buffer)) != 0) {
-		return false;
-	}
-	return true;
-}
-
-enum GBARRTag _readTag(struct GBARRContext* rr, struct VFile* vf) {
-	if (!rr || !vf) {
-		return TAG_EOF;
-	}
-
-	enum GBARRTag tag = rr->peekedTag;
-	switch (tag) {
-	case TAG_INPUT:
-		vf->read(vf, &rr->currentInput, sizeof(uint16_t));
-		break;
-	case TAG_PREVIOUSLY:
-		vf->read(vf, &rr->previously, sizeof(rr->previously));
-		break;
-	case TAG_NEXT_TIME:
-		vf->read(vf, &rr->nextTime, sizeof(rr->nextTime));
-		break;
-	case TAG_MAX_STREAM:
-		vf->read(vf, &rr->maxStreamId, sizeof(rr->maxStreamId));
-		break;
-	case TAG_FRAME_COUNT:
-		vf->read(vf, &rr->frames, sizeof(rr->frames));
-		break;
-	case TAG_LAG_COUNT:
-		vf->read(vf, &rr->lagFrames, sizeof(rr->lagFrames));
-		break;
-	case TAG_RR_COUNT:
-		vf->read(vf, &rr->rrCount, sizeof(rr->rrCount));
-		break;
-
-	case TAG_INIT_EX_NIHILO:
-		rr->initFrom = INIT_EX_NIHILO;
-		break;
-	case TAG_INIT_FROM_SAVEGAME:
-		rr->initFrom = INIT_FROM_SAVEGAME;
-		break;
-	case TAG_INIT_FROM_SAVESTATE:
-		rr->initFrom = INIT_FROM_SAVESTATE;
-		break;
-	case TAG_INIT_FROM_BOTH:
-		rr->initFrom = INIT_FROM_BOTH;
-		break;
-
-	// To be spec'd
-	case TAG_AUTHOR:
-	case TAG_COMMENT:
-		break;
-
-	// Empty markers
-	case TAG_FRAME:
-	case TAG_LAG:
-	case TAG_BEGIN:
-	case TAG_END:
-	case TAG_INVALID:
-	case TAG_EOF:
-		break;
-	}
-
-	uint8_t tagBuffer;
-	if (vf->read(vf, &tagBuffer, 1) != 1) {
-		rr->peekedTag = TAG_EOF;
-	} else {
-		rr->peekedTag = tagBuffer;
-	}
-
-	if (rr->peekedTag == TAG_END) {
-		GBARRSkipSegment(rr);
-	}
-	return tag;
-}
-
-bool _seekTag(struct GBARRContext* rr, struct VFile* vf, enum GBARRTag tag) {
-	enum GBARRTag readTag;
-	while ((readTag = _readTag(rr, vf)) != tag) {
-		if (readTag == TAG_EOF) {
-			return false;
-		}
-	}
-	return true;
-}
-
-bool _emitTag(struct GBARRContext* rr, struct VFile* vf, uint8_t tag) {
-	UNUSED(rr);
-	return vf->write(vf, &tag, sizeof(tag)) == sizeof(tag);
-}
-
-bool _parseMetadata(struct GBARRContext* rr, struct VFile* vf) {
-	if (!_verifyMagic(rr, vf)) {
-		return false;
-	}
-	while (_readTag(rr, vf) != TAG_EOF) {
-		switch (rr->peekedTag) {
-		case TAG_MAX_STREAM:
-			rr->maxStreamIdOffset = vf->seek(vf, 0, SEEK_CUR);
-			break;
-		case TAG_INIT_EX_NIHILO:
-		case TAG_INIT_FROM_SAVEGAME:
-		case TAG_INIT_FROM_SAVESTATE:
-		case TAG_INIT_FROM_BOTH:
-			rr->initFromOffset = vf->seek(vf, 0, SEEK_CUR);
-			break;
-		case TAG_RR_COUNT:
-			rr->rrCountOffset = vf->seek(vf, 0, SEEK_CUR);
-			break;
-		default:
-			break;
-		}
-	}
-	return true;
-}
-
-bool _emitEnd(struct GBARRContext* rr, struct VFile* vf) {
-	// TODO: Error check
-	_emitTag(rr, vf, TAG_END);
-	_emitTag(rr, vf, TAG_FRAME_COUNT);
-	vf->write(vf, &rr->frames, sizeof(rr->frames));
-	_emitTag(rr, vf, TAG_LAG_COUNT);
-	vf->write(vf, &rr->lagFrames, sizeof(rr->lagFrames));
-	_emitTag(rr, vf, TAG_NEXT_TIME);
-
-	uint32_t newStreamId = 0;
-	vf->write(vf, &newStreamId, sizeof(newStreamId));
-	return true;
-}
-
-bool _markStreamNext(struct GBARRContext* rr, uint32_t newStreamId, bool recursive) {
-	if (rr->movieStream->seek(rr->movieStream, -sizeof(newStreamId) - 1, SEEK_END) < 0) {
-		return false;
-	}
-
-	uint8_t tagBuffer;
-	if (rr->movieStream->read(rr->movieStream, &tagBuffer, 1) != 1) {
-		return false;
-	}
-	if (tagBuffer != TAG_NEXT_TIME) {
-		return false;
-	}
-	if (rr->movieStream->write(rr->movieStream, &newStreamId, sizeof(newStreamId)) != sizeof(newStreamId)) {
-		return false;
-	}
-	if (recursive) {
-		if (rr->movieStream->seek(rr->movieStream, 0, SEEK_SET) < 0) {
-			return false;
-		}
-		if (!_verifyMagic(rr, rr->movieStream)) {
-			return false;
-		}
-		_readTag(rr, rr->movieStream);
-		if (_readTag(rr, rr->movieStream) != TAG_PREVIOUSLY) {
-			return false;
-		}
-		if (rr->previously == 0) {
-			return true;
-		}
-		uint32_t currentStreamId = rr->streamId;
-		if (!GBARRLoadStream(rr, rr->previously)) {
-			return false;
-		}
-		return _markStreamNext(rr, currentStreamId, rr->previously);
-	}
-	return true;
-}
-
-void _streamEndReached(struct GBARRContext* rr) {
-	if (!GBARRIsPlaying(rr)) {
-		return;
-	}
-
-	uint32_t endStreamId = rr->streamId;
-	GBARRStopPlaying(rr);
-	if (rr->autorecord) {
-		rr->isRecording = true;
-		GBARRLoadStream(rr, endStreamId);
-		GBARRIncrementStream(rr, false);
-	}
-}
-
-struct VFile* _openSavedata(struct GBARRContext* rr, int flags) {
-	return rr->streamDir->openFile(rr->streamDir, "movie.sav", flags);
-}
-
-struct VFile* _openSavestate(struct GBARRContext* rr, int flags) {
-	return rr->streamDir->openFile(rr->streamDir, "movie.ssm", flags);
-}
diff --git a/src/gba/supervisor/rr.h b/src/gba/supervisor/rr.h
index fb94ae02d..ae0b2b832 100644
--- a/src/gba/supervisor/rr.h
+++ b/src/gba/supervisor/rr.h
@@ -8,8 +8,8 @@
 
 #include "util/common.h"
 
-struct GBA;
-struct VDir;
+#include "gba/serialize.h"
+
 struct VFile;
 
 enum GBARRInitFrom {
@@ -19,95 +19,32 @@ enum GBARRInitFrom {
 	INIT_FROM_BOTH = 3,
 };
 
-enum GBARRTag {
-	// Playback tags
-	TAG_INVALID = 0x00,
-	TAG_INPUT = 0x01,
-	TAG_FRAME = 0x02,
-	TAG_LAG = 0x03,
-
-	// Stream chunking tags
-	TAG_BEGIN = 0x10,
-	TAG_END = 0x11,
-	TAG_PREVIOUSLY = 0x12,
-	TAG_NEXT_TIME = 0x13,
-	TAG_MAX_STREAM = 0x14,
-
-	// Recording information tags
-	TAG_FRAME_COUNT = 0x20,
-	TAG_LAG_COUNT = 0x21,
-	TAG_RR_COUNT = 0x22,
-	TAG_INIT = 0x24,
-	TAG_INIT_EX_NIHILO = 0x24 | INIT_EX_NIHILO,
-	TAG_INIT_FROM_SAVEGAME = 0x24 | INIT_FROM_SAVEGAME,
-	TAG_INIT_FROM_SAVESTATE = 0x24 | INIT_FROM_SAVESTATE,
-	TAG_INIT_FROM_BOTH = 0x24 | INIT_FROM_BOTH,
-
-	// User metadata tags
-	TAG_AUTHOR = 0x30,
-	TAG_COMMENT = 0x31,
-
-	TAG_EOF = INT_MAX
-};
-
 struct GBARRContext {
-	// Playback state
-	bool isPlaying;
-	bool autorecord;
+	bool (*startPlaying)(struct GBARRContext*, bool autorecord);
+	void (*stopPlaying)(struct GBARRContext*);
+	bool (*startRecording)(struct GBARRContext*);
+	void (*stopRecording)(struct GBARRContext*);
 
-	// Recording state
-	bool isRecording;
-	bool inputThisFrame;
+	bool (*isPlaying)(const struct GBARRContext*);
+	bool (*isRecording)(const struct GBARRContext*);
+
+	void (*nextFrame)(struct GBARRContext*);
+	void (*logInput)(struct GBARRContext*, uint16_t input);
+	uint16_t (*queryInput)(struct GBARRContext*);
+
+	void (*stateSaved)(struct GBARRContext*, struct GBASerializedState*);
+	void (*stateLoaded)(struct GBARRContext*, const struct GBASerializedState*);
+
+	struct VFile* (*openSavedata)(struct GBARRContext* mgm, int flags);
+	struct VFile* (*openSavestate)(struct GBARRContext* mgm, int flags);
 
-	// Metadata
 	uint32_t frames;
 	uint32_t lagFrames;
-	uint32_t streamId;
-
-	uint32_t maxStreamId;
-	off_t maxStreamIdOffset;
-
 	enum GBARRInitFrom initFrom;
-	off_t initFromOffset;
 
 	uint32_t rrCount;
-	off_t rrCountOffset;
 
 	struct VFile* savedata;
-
-	// Streaming state
-	struct VDir* streamDir;
-	struct VFile* metadataFile;
-	struct VFile* movieStream;
-	uint16_t currentInput;
-	enum GBARRTag peekedTag;
-	uint32_t nextTime;
-	uint32_t previously;
 };
 
-void GBARRContextCreate(struct GBA*);
-void GBARRContextDestroy(struct GBA*);
-void GBARRSaveState(struct GBA*);
-void GBARRLoadState(struct GBA*);
-
-bool GBARRInitStream(struct GBARRContext*, struct VDir*);
-bool GBARRReinitStream(struct GBARRContext*, enum GBARRInitFrom);
-bool GBARRLoadStream(struct GBARRContext*, uint32_t streamId);
-bool GBARRIncrementStream(struct GBARRContext*, bool recursive);
-bool GBARRFinishSegment(struct GBARRContext*);
-bool GBARRSkipSegment(struct GBARRContext*);
-bool GBARRMarkRerecord(struct GBARRContext*);
-
-bool GBARRStartPlaying(struct GBARRContext*, bool autorecord);
-void GBARRStopPlaying(struct GBARRContext*);
-bool GBARRStartRecording(struct GBARRContext*);
-void GBARRStopRecording(struct GBARRContext*);
-
-bool GBARRIsPlaying(struct GBARRContext*);
-bool GBARRIsRecording(struct GBARRContext*);
-
-void GBARRNextFrame(struct GBARRContext*);
-void GBARRLogInput(struct GBARRContext*, uint16_t input);
-uint16_t GBARRQueryInput(struct GBARRContext*);
-
 #endif