media/media-add-ons/AbstractFileInterfaceNode.cpp

// AbstractFileInterfaceNode.cpp
//
// Andrew Bachmann, 2002
//
// The AbstractFileInterfaceNode class implements
// the common functionality between MediaReader
// and MediaWriter.
#include "AbstractFileInterfaceNode.h"
#include "debug.h"

#include <Buffer.h>
#include <Controllable.h>
#include <Entry.h>
#include <Errors.h>
#include <File.h>
#include <FileInterface.h>
#include <MediaDefs.h>
#include <MediaEventLooper.h>
#include <MediaNode.h>
#include <TimeSource.h>
#include <ParameterWeb.h>
#include <limits.h>
#include <stdio.h>
#include <string.h>


AbstractFileInterfaceNode::~AbstractFileInterfaceNode(void)
{
	CALLED();

	// Stop the BMediaEventLooper thread
	Quit();
	if (fCurrentFile != 0)
		delete fCurrentFile;
}


AbstractFileInterfaceNode::AbstractFileInterfaceNode(
				size_t defaultChunkSize,
				float defaultBitRate,
				const flavor_info * info,
				BMessage * config,
				BMediaAddOn * addOn)
	: BMediaNode("AbstractFileInterfaceNode"),
	  BFileInterface(),
	  BControllable(),
	  BMediaEventLooper()
{
	CALLED();

	// keep our creator around for AddOn calls later
	fAddOn = addOn;
	// null some fields
	fCurrentFile = 0;
	f_current_mime_type[0] = '\0';

	// initialize the parameters
	if (defaultChunkSize <= 0) {
		fInitCheckStatus = B_BAD_VALUE;
		return;
	}

	fDefaultChunkSizeParam = defaultChunkSize;
	fDefaultChunkSizeParamChangeTime = 0;
	if (defaultBitRate <= 0) {
		fInitCheckStatus = B_BAD_VALUE;
		return;
	}

	fDefaultBitRateParam = defaultBitRate;
	fDefaultBitRateParamChangeTime = 0;
	// initialize parameter compute fields
	fLeastRecentlyUpdatedParameter = DEFAULT_BIT_RATE_PARAM;
	fLastUpdatedParameter = DEFAULT_BUFFER_PERIOD_PARAM;
	// From the chunk size and bit rate we compute the buffer period.
	int64 value = int64(8000000/1024*fDefaultChunkSizeParam/fDefaultBitRateParam);
	if ((value <= 0) || (value > INT_MAX)) {
		fInitCheckStatus = B_BAD_VALUE;
		return;
	}
	fDefaultBufferPeriodParam = int32(value);
	fDefaultBufferPeriodParamChangeTime = 0;

	fInitCheckStatus = B_OK;
}


status_t AbstractFileInterfaceNode::InitCheck(void) const
{
	CALLED();
	return fInitCheckStatus;
}


status_t AbstractFileInterfaceNode::GetConfigurationFor(
				BMessage * into_message)
{
	CALLED();
	return B_OK;
}


// -------------------------------------------------------- //
// implementation of BMediaNode
// -------------------------------------------------------- //
BMediaAddOn * AbstractFileInterfaceNode::AddOn(
				int32 * internal_id) const
{
	CALLED();
	// BeBook says this only gets called if we were in an add-on.
	if (fAddOn != 0) {
		// If we get a null pointer then we just won't write.
		if (internal_id != 0)
			internal_id = 0;
	}
	return fAddOn;
}


void AbstractFileInterfaceNode::Start(
				bigtime_t performance_time)
{
	PRINT("AbstractFileInterfaceNode::Start(pt=%lld)\n",performance_time);
	BMediaEventLooper::Start(performance_time);
}


void AbstractFileInterfaceNode::Stop(
				bigtime_t performance_time,
				bool immediate)
{
	PRINT("AbstractFileInterfaceNode::Stop(pt=%lld, im=%d)\n",
		  performance_time, immediate);
	BMediaEventLooper::Stop(performance_time,immediate);
}


void AbstractFileInterfaceNode::Seek(
				bigtime_t media_time,
				bigtime_t performance_time)
{
	PRINT("AbstractFileInterfaceNode::Seek(mt=%lld,pt=%lld)\n",
		  media_time,performance_time);
	BMediaEventLooper::Seek(media_time,performance_time);
}


void AbstractFileInterfaceNode::SetRunMode(
				run_mode mode)
{
	PRINT("AbstractFileInterfaceNode::SetRunMode(%i)\n",mode);
	BMediaEventLooper::SetRunMode(mode);
}


void AbstractFileInterfaceNode::TimeWarp(
				bigtime_t at_real_time,
				bigtime_t to_performance_time)
{
	PRINT("AbstractFileInterfaceNode::TimeWarp(rt=%lld,pt=%lld)\n",
		  at_real_time,to_performance_time);
	BMediaEventLooper::TimeWarp(at_real_time,to_performance_time);
}


void AbstractFileInterfaceNode::Preroll(void)
{
	CALLED();
	// XXX:Performance opportunity
	BMediaNode::Preroll();
}


void AbstractFileInterfaceNode::SetTimeSource(
				BTimeSource * time_source)
{
	CALLED();
	BMediaNode::SetTimeSource(time_source);
}


status_t AbstractFileInterfaceNode::HandleMessage(
				int32 message,
				const void * data,
				size_t size)
{
	CALLED();

	status_t status = B_OK;
	switch (message) {
		// no special messages for now
		default:
			status = BFileInterface::HandleMessage(message,data,size);
			if (status == B_OK) {
				break;
			}
			status = BControllable::HandleMessage(message, data, size);
			if (status == B_OK)
				break;
			status = BMediaNode::HandleMessage(message,data,size);
			if (status == B_OK) {
				break;
			}
			BMediaNode::HandleBadMessage(message,data,size);
			status = B_ERROR;
			break;
	}
	return status;
}


status_t AbstractFileInterfaceNode::RequestCompleted(
				const media_request_info & info)
{
	CALLED();
	return BMediaNode::RequestCompleted(info);
}


status_t AbstractFileInterfaceNode::DeleteHook(
				BMediaNode * node)
{
	CALLED();
	return BMediaEventLooper::DeleteHook(node);
}


void AbstractFileInterfaceNode::NodeRegistered(void)
{
	CALLED();

	// set up our parameter web
	SetParameterWeb(MakeParameterWeb());

	// start the BMediaEventLooper thread
	SetPriority(B_REAL_TIME_PRIORITY);
	Run();
}


status_t AbstractFileInterfaceNode::GetNodeAttributes(
				media_node_attribute * outAttributes,
				size_t inMaxCount)
{
	CALLED();
	return BMediaNode::GetNodeAttributes(outAttributes,inMaxCount);
}


status_t AbstractFileInterfaceNode::AddTimer(
					bigtime_t at_performance_time,
					int32 cookie)
{
	CALLED();
	return BMediaEventLooper::AddTimer(at_performance_time,cookie);
}


// protected:
BParameterWeb * AbstractFileInterfaceNode::MakeParameterWeb(void)
{
	CALLED();

	BParameterWeb * web = new BParameterWeb();
	BParameterGroup * mainGroup = web->MakeGroup("AbstractFileInterfaceNode Parameters");

	// these three are related:
	// DEFAULT_CHUNK_SIZE_PARAM =
	// DEFAULT_BIT_RATE_PARAM / 1024 * DEFAULT_BUFFER_PERIOD_PARAM * 1000
	BParameterGroup * chunkSizeGroup = mainGroup->MakeGroup("Chunk Size Group");
	BContinuousParameter * chunkSizeParameter
	   = chunkSizeGroup->MakeContinuousParameter(
	     DEFAULT_CHUNK_SIZE_PARAM, B_MEDIA_MULTISTREAM,
		 "Chunk Size", B_GAIN, "bytes", 1024, 32*1024, 512);
	chunkSizeParameter->SetResponse(BContinuousParameter::B_LINEAR,1,0);
	chunkSizeParameter->SetValue(&fDefaultChunkSizeParam,sizeof(fDefaultChunkSizeParam),0);

	BParameterGroup * bitRateGroup = mainGroup->MakeGroup("Bit Rate Group");
	BContinuousParameter * bitRateParameter
	   = bitRateGroup->MakeContinuousParameter(
	     DEFAULT_BIT_RATE_PARAM, B_MEDIA_MULTISTREAM,
	     "Bit Rate", B_GAIN, "kbits/sec", 1, 320000, 1);
	bitRateParameter->SetResponse(BContinuousParameter::B_LINEAR,.001,0);
	bitRateParameter->SetValue(&fDefaultBitRateParam,sizeof(fDefaultBitRateParam),0);

	BParameterGroup * bufferPeriodGroup = mainGroup->MakeGroup("Buffer Period Group");
	BContinuousParameter * bufferPeriodParameter
	   = bufferPeriodGroup->MakeContinuousParameter(
	     DEFAULT_BUFFER_PERIOD_PARAM, B_MEDIA_MULTISTREAM,
	     "Buffer Period", B_GAIN, "ms", 1, 10000, 1);
	bufferPeriodParameter->SetResponse(BContinuousParameter::B_LINEAR,1,0);
	bufferPeriodParameter->SetValue(&fDefaultBufferPeriodParam,sizeof(fDefaultBufferPeriodParam),0);

	return web;
}


// -------------------------------------------------------- //
// implementation of BFileInterface
// -------------------------------------------------------- //
status_t AbstractFileInterfaceNode::GetNextFileFormat(
				int32 * cookie,
				media_file_format * out_format)
{
	CALLED();

	// it's valid but they already got our 1 file format
	if (*cookie != 0) {
		PRINT("\t<- B_ERROR\n");
		return B_ERROR;
	}

	// so next time they won't get the same format again
	*cookie = 1;
	GetFileFormat(out_format);
	return B_OK;
}


void AbstractFileInterfaceNode::DisposeFileFormatCookie(
				int32 cookie)
{
	CALLED();
	// nothing to do since our cookies are just integers
}


status_t AbstractFileInterfaceNode::GetDuration(
				bigtime_t * out_time)
{
	CALLED();
	if (out_time == 0) {
		PRINT("\t<- B_BAD_VALUE\n");
		return B_BAD_VALUE;
	}

	if (fCurrentFile == 0) {
		PRINT("\t<- B_NO_INIT\n");
		return B_NO_INIT;
	}

	return fCurrentFile->GetSize(out_time);
}


status_t AbstractFileInterfaceNode::SniffRef(
				const entry_ref & file,
				char * out_mime_type,	/* 256 bytes */
				float * out_quality)
{
	CALLED();
	return StaticSniffRef(file,out_mime_type,out_quality);
}


status_t AbstractFileInterfaceNode::SetRef(
				const entry_ref & file,
				uint32 openMode,
				bool create,
				bigtime_t * out_time)
{
	CALLED();

	status_t status;
	f_current_ref = file;
	if (fCurrentFile == 0) {
		fCurrentFile = new BFile(&f_current_ref,(openMode|(create?B_CREATE_FILE:0)));
		status = fCurrentFile->InitCheck();
	} else {
		status = fCurrentFile->SetTo(&f_current_ref,(openMode|(create?B_CREATE_FILE:0)));
	}

	if (status != B_OK) {
		PRINT("\t<- failed BFile initialization\n");
		return status;
	}

	// cache the mime type for later
	fCurrentFile->ReadAttr("BEOS:TYPE",0,0,f_current_mime_type,B_MIME_TYPE_LENGTH);
	// compute the duration and return any error
	return GetDuration(out_time);
}


status_t AbstractFileInterfaceNode::GetRef(
				entry_ref * out_ref,
				char * out_mime_type)
{
	CALLED();

	if (fCurrentFile == 0) {
		PRINT("\t<- B_NO_INIT\n");
		return B_NO_INIT; // the input_ref isn't valid yet either
	}

	*out_ref = f_current_ref;
	// they hopefully allocated enough space (no way to check :-/ )
	strcpy(out_mime_type,f_current_mime_type);
	return B_OK;
}


// provided for BAbstractFileInterfaceNodeAddOn
status_t AbstractFileInterfaceNode::StaticSniffRef(
				const entry_ref & file,
				char * out_mime_type,	/* 256 bytes */
				float * out_quality)
{
	CALLED();

	BNode node(&file);
	status_t initCheck = node.InitCheck();
	if (initCheck != B_OK) {
		PRINT("\t<- failed BNode::InitCheck()\n");
		return initCheck;
	}

	// they hopefully allocated enough room
	node.ReadAttr("BEOS:TYPE",0,0,out_mime_type,B_MIME_TYPE_LENGTH);
	*out_quality = 1.0; // we handle all files perfectly!  we are so amazing!
	return B_OK;
}


// -------------------------------------------------------- //
// implementation for BControllable
// -------------------------------------------------------- //
const int32 AbstractFileInterfaceNode::DEFAULT_CHUNK_SIZE_PARAM = 1;
const int32 AbstractFileInterfaceNode::DEFAULT_BIT_RATE_PARAM = 2;
const int32 AbstractFileInterfaceNode::DEFAULT_BUFFER_PERIOD_PARAM = 3;


status_t AbstractFileInterfaceNode::GetParameterValue(
				int32 id,
				bigtime_t * last_change,
				void * value,
				size_t * ioSize)
{
	CALLED();

	switch (id) {
		case DEFAULT_CHUNK_SIZE_PARAM:
			if (*ioSize < sizeof(size_t)) {
				return B_ERROR; // not enough room
			}
			*last_change = fDefaultChunkSizeParamChangeTime;
			*((size_t*)value) = fDefaultChunkSizeParam;
			*ioSize = sizeof(size_t);
			break;

		case DEFAULT_BIT_RATE_PARAM:
			if (*ioSize < sizeof(float)) {
				return B_ERROR; // not enough room
			}
			*last_change = fDefaultBitRateParamChangeTime;
			*((float*)value) = fDefaultBitRateParam;
			*ioSize = sizeof(float);
			break;

		case DEFAULT_BUFFER_PERIOD_PARAM:
			if (*ioSize < sizeof(int32)) {
				return B_ERROR; // not enough room
			}
			*last_change = fDefaultBufferPeriodParamChangeTime;
			*((int32*)value) = fDefaultBufferPeriodParam;
			*ioSize = sizeof(int32);
			break;

		default:
			PRINT("AbstractFileInterfaceNode::GetParameterValue unknown id (%ld)\n",id);
			return B_ERROR;
	}

	return B_OK;
}


void AbstractFileInterfaceNode::SetParameterValue(
				int32 id,
				bigtime_t when,
				const void * value,
				size_t size)
{
	PRINT("AbstractFileInterfaceNode::SetParameterValue(id=%ld,when=%lld,size=%ld)\n",id,when,int32(size));

	switch (id) {
		case DEFAULT_CHUNK_SIZE_PARAM:
		case DEFAULT_BIT_RATE_PARAM:
		case DEFAULT_BUFFER_PERIOD_PARAM:
			{
				media_timed_event event(when, BTimedEventQueue::B_PARAMETER,
										NULL, BTimedEventQueue::B_NO_CLEANUP,
										size, id, (char*) value, size);
				EventQueue()->AddEvent(event);
			}
			break;

		default:
			PRINT("AbstractFileInterfaceNode::SetParameterValue unknown id (%ld)\n",id);
			break;
	}
}


// the default implementation should call the add-on main()
status_t AbstractFileInterfaceNode::StartControlPanel(
				BMessenger * out_messenger)
{
	CALLED();
	return BControllable::StartControlPanel(out_messenger);
}


// -------------------------------------------------------- //
// implementation for BMediaEventLooper
// -------------------------------------------------------- //
void AbstractFileInterfaceNode::HandleEvent(
				const media_timed_event *event,
				bigtime_t lateness,
				bool realTimeEvent)
{
	CALLED();
	switch (event->type) {
		case BTimedEventQueue::B_START:
			HandleStart(event,lateness,realTimeEvent);
			break;
		case BTimedEventQueue::B_SEEK:
			HandleSeek(event,lateness,realTimeEvent);
			break;
		case BTimedEventQueue::B_WARP:
			HandleWarp(event,lateness,realTimeEvent);
			break;
		case BTimedEventQueue::B_STOP:
			HandleStop(event,lateness,realTimeEvent);
			break;
		case BTimedEventQueue::B_HANDLE_BUFFER:
			if (RunState() == BMediaEventLooper::B_STARTED) {
				HandleBuffer(event,lateness,realTimeEvent);
			}
			break;
		case BTimedEventQueue::B_DATA_STATUS:
			HandleDataStatus(event,lateness,realTimeEvent);
			break;
		case BTimedEventQueue::B_PARAMETER:
			HandleParameter(event,lateness,realTimeEvent);
			break;
		default:
			PRINT("  unknown event type: %ld\n",event->type);
			break;
	}
}


/* override to clean up custom events you have added to your queue */
void AbstractFileInterfaceNode::CleanUpEvent(
				const media_timed_event *event)
{
	BMediaEventLooper::CleanUpEvent(event);
}


/* called from Offline mode to determine the current time of the node */
/* update your internal information whenever it changes */
bigtime_t AbstractFileInterfaceNode::OfflineTime()
{
	CALLED();
	return BMediaEventLooper::OfflineTime();
	// XXX: do something else?
	//	if (inputFile == 0) {
	//		return 0;
	//	} else {
	//		return inputFile->Position();
	//	}
}


/* override only if you know what you are doing! */
/* otherwise much badness could occur */
/* the actual control loop function: */
/* 	waits for messages, Pops events off the queue and calls DispatchEvent */
void AbstractFileInterfaceNode::ControlLoop() {
	BMediaEventLooper::ControlLoop();
}


// protected:
status_t AbstractFileInterfaceNode::HandleStart(
						const media_timed_event *event,
						bigtime_t lateness,
						bool realTimeEvent)
{
	CALLED();

	if (RunState() != B_STARTED) {
		// XXX: Either use the following line or the lines that are not commented.
		// There doesn't seem to be a practical difference that i can tell.
		//		HandleBuffer(event,lateness,realTimeEvent);
		media_timed_event firstBufferEvent(event->event_time, BTimedEventQueue::B_HANDLE_BUFFER);
		HandleEvent(&firstBufferEvent, 0, false);
		EventQueue()->AddEvent(firstBufferEvent);
	}
	return B_OK;
}


status_t AbstractFileInterfaceNode::HandleSeek(
						const media_timed_event *event,
						bigtime_t lateness,
						bool realTimeEvent)
{
	PRINT("AbstractFileInterfaceNode::HandleSeek(t=%lld,d=%ld,bd=%lld)\n",event->event_time,event->data,event->bigdata);

	if (fCurrentFile != 0)
		return fCurrentFile->Seek(event->bigdata,SEEK_SET);
	else
		return B_ERROR;
}


status_t AbstractFileInterfaceNode::HandleWarp(
						const media_timed_event *event,
						bigtime_t lateness,
						bool realTimeEvent)
{
	CALLED();
	return B_OK;
}


status_t AbstractFileInterfaceNode::HandleStop(
						const media_timed_event *event,
						bigtime_t lateness,
						bool realTimeEvent)
{
	CALLED();

	// flush the queue so downstreamers don't get any more
	EventQueue()->FlushEvents(0, BTimedEventQueue::B_ALWAYS, true, BTimedEventQueue::B_HANDLE_BUFFER);
	return B_OK;
}


status_t AbstractFileInterfaceNode::HandleParameter(
				const media_timed_event *event,
				bigtime_t lateness,
				bool realTimeEvent)
{
	CALLED();

	status_t status = B_OK;

	bool chunkSizeUpdated = false, bitRateUpdated = false, bufferPeriodUpdated = false;

	size_t dataSize = size_t(event->data);
	int64 param = int64(event->bigdata);

	switch (param) {
		case DEFAULT_CHUNK_SIZE_PARAM:
			PRINT("(DEFAULT_CHUNK_SIZE_PARAM,size=%ld",dataSize);
			if (dataSize < sizeof(size_t)) {
				PRINT("\ŧ<- B_BAD_VALUE: %lld\n",param);
				status = B_BAD_VALUE;
			} else {
				size_t newDefaultChunkSize = *((size_t*)event->user_data);
				PRINT(",%ld)\n", newDefaultChunkSize);
				// ignore non positive chunk sizes
				// XXX: we may decide later that a 0 chunk size means ship the whole file in one chunk (!)
				if ((newDefaultChunkSize > 0) && (newDefaultChunkSize != fDefaultChunkSizeParam)) {
					PRINT("\tgot a new chunk size, old chunk size was %ld\n",fDefaultChunkSizeParam);
					fDefaultChunkSizeParam = newDefaultChunkSize;
					fDefaultChunkSizeParamChangeTime = TimeSource()->Now();
					chunkSizeUpdated = true;
					if (fLeastRecentlyUpdatedParameter == DEFAULT_CHUNK_SIZE_PARAM) {
						// Okay we were the least recently updated parameter,
						// but we just got an update so we are no longer that.
						// Let's figure out who the new least recently updated
						// parameter is.  We are going to prefer to compute the
						// bit rate since you usually don't want to muck with
						// the buffer period.  However, if you just set the bitrate
						// then we are stuck with making the buffer period the new
						// parameter to be computed.
						if (fLastUpdatedParameter == DEFAULT_BIT_RATE_PARAM)
							fLeastRecentlyUpdatedParameter = DEFAULT_BUFFER_PERIOD_PARAM;
						else
							fLeastRecentlyUpdatedParameter = DEFAULT_BIT_RATE_PARAM;
					}
					// we just got an update, so we are the new lastUpdatedParameter
					fLastUpdatedParameter = DEFAULT_CHUNK_SIZE_PARAM;
					// now we have to compute the new value for the leastRecentlyUpdatedParameter
					// we use the chunk size change time to preserve "simultaneity" information
					if (fLeastRecentlyUpdatedParameter == DEFAULT_BUFFER_PERIOD_PARAM) {
						int64 value = int64(8000000/1024*fDefaultChunkSizeParam/fDefaultBitRateParam);
						if (value > INT_MAX) {
							// clamp to INT_MAX
							fDefaultBufferPeriodParam = INT_MAX;
							// recompute chunk size
							fDefaultChunkSizeParam = size_t(1024/8000000*fDefaultBitRateParam*fDefaultBufferPeriodParam);
						} else {
							fDefaultBufferPeriodParam = MAX(1,value);
						}
						fDefaultBufferPeriodParamChangeTime = fDefaultChunkSizeParamChangeTime;
						bufferPeriodUpdated = true;
					} else { // must have been bit rate
						fDefaultBitRateParam = MAX(0.001,8000000/1024*fDefaultChunkSizeParam/fDefaultBufferPeriodParam);
						fDefaultBitRateParamChangeTime = fDefaultChunkSizeParamChangeTime;
						bitRateUpdated = true;
					}
				}
			}
			break;
		case DEFAULT_BIT_RATE_PARAM:
			PRINT("(DEFAULT_BIT_RATE_PARAM,size=%ld",dataSize);
			if (dataSize < sizeof(float)) {
				PRINT("\t<- B_BAD_VALUE:lld\n",param);
				status = B_BAD_VALUE;
			} else {
				float newDefaultBitRate = *((float*)event->user_data);
				PRINT(",%f)\n",newDefaultBitRate);
				// ignore non positive bitrates
				if ((newDefaultBitRate > 0) && (newDefaultBitRate != fDefaultBitRateParam)) {
					PRINT("\tgot a new bit rate, old bit rate was %ld\n",fDefaultBitRateParam);
					fDefaultBitRateParam = newDefaultBitRate;
					fDefaultBitRateParamChangeTime = TimeSource()->Now();
					bitRateUpdated = true;
					if (fLeastRecentlyUpdatedParameter == DEFAULT_BIT_RATE_PARAM) {
						// Okay we were the least recently updated parameter,
						// but we just got an update so we are no longer that.
						// Let's figure out who the new least recently updated
						// parameter is.  We are going to prefer to compute the
						// chunk size since you usually don't want to muck with
						// the buffer period.  However, if you just set the chunk size
						// then we are stuck with making the buffer period the new
						// parameter to be computed.
						if (fLastUpdatedParameter == DEFAULT_CHUNK_SIZE_PARAM) {
							fLeastRecentlyUpdatedParameter = DEFAULT_BUFFER_PERIOD_PARAM;
						} else {
							fLeastRecentlyUpdatedParameter = DEFAULT_CHUNK_SIZE_PARAM;
						}
					}
					// we just got an update, so we are the new lastUpdatedParameter
					fLastUpdatedParameter = DEFAULT_BIT_RATE_PARAM;
					// now we have to compute the new value for the leastRecentlyUpdatedParameter
					// we use the bit rate change time to preserve "simultaneity" information
					if (fLeastRecentlyUpdatedParameter == DEFAULT_BUFFER_PERIOD_PARAM) {
						int64 value =
								int64(8000000/1024*fDefaultChunkSizeParam/fDefaultBitRateParam);
						if (value > INT_MAX) {
							// clamp to INT_MAX
							fDefaultBufferPeriodParam = INT_MAX;
							// recompute bit rate
							fDefaultBitRateParam = MAX(0.001,
										8000000/1024*fDefaultChunkSizeParam/fDefaultBufferPeriodParam);
						} else {
							fDefaultBufferPeriodParam = MAX(1,int32(value));
						}
						fDefaultBufferPeriodParamChangeTime = fDefaultBitRateParamChangeTime;
						bufferPeriodUpdated = true;
					} else { // must have been chunk size
						int64 value =
								int64(1024/8000000*fDefaultBitRateParam*fDefaultBufferPeriodParam);
						if (value > INT_MAX) {
							// clamp to INT_MAX
							fDefaultChunkSizeParam = INT_MAX;
							// recompute bit rate
							fDefaultBitRateParam =
									MAX(0.001,8000000/1024*fDefaultChunkSizeParam/fDefaultBufferPeriodParam);
						} else {
							fDefaultChunkSizeParam = MAX(1,int32(value));
						}
						fDefaultChunkSizeParamChangeTime = fDefaultBitRateParamChangeTime;
						chunkSizeUpdated = true;
					}
				}
			}
			break;
		case DEFAULT_BUFFER_PERIOD_PARAM:
			PRINT("(DEFAULT_BUFFER_PERIOD_PARAM,size=%ld",dataSize);
			if (dataSize < sizeof(int32)) {
				PRINT("\t<- B_BAD_VALUE:%ld\n",param);
				status = B_BAD_VALUE;
			} else {
				int32 newBufferPeriod = *((int32*)event->user_data);
				PRINT(",%ld)\n",newBufferPeriod);
				// ignore non positive buffer period
				if ((newBufferPeriod > 0) && (newBufferPeriod != fDefaultBufferPeriodParam)) {
					PRINT("\tgot a new buffer period, old buffer period was %ld\n",
						  fDefaultBufferPeriodParam);
					fDefaultBufferPeriodParam = newBufferPeriod;
					fDefaultBufferPeriodParamChangeTime = TimeSource()->Now();
					bufferPeriodUpdated = true;
					if (fLastUpdatedParameter == DEFAULT_BUFFER_PERIOD_PARAM) {
						// prefer to update bit rate, unless you just set it
						if (fLastUpdatedParameter == DEFAULT_BIT_RATE_PARAM) {
							fLeastRecentlyUpdatedParameter = DEFAULT_CHUNK_SIZE_PARAM;
						} else {
							fLeastRecentlyUpdatedParameter = DEFAULT_BIT_RATE_PARAM;
						}
					}
					// we just got an update, so we are the new lastUpdatedParameter
					fLastUpdatedParameter = DEFAULT_BUFFER_PERIOD_PARAM;
					// now we have to compute the new value for the leastRecentlyUpdatedParameter
					// we use the buffer period change time to preserve "simultaneity" information
					if (fLeastRecentlyUpdatedParameter == DEFAULT_BIT_RATE_PARAM) {
						fDefaultBitRateParam =
								MAX(0.001,8000000/1024*fDefaultChunkSizeParam/fDefaultBufferPeriodParam);
						fDefaultBitRateParamChangeTime = fDefaultBufferPeriodParamChangeTime;
						bitRateUpdated = true;
					} else { // must have been chunk size
						int64 value = int64(1024/8000000*fDefaultBitRateParam*fDefaultBufferPeriodParam);
						if (value > INT_MAX) {
							// clamp to INT_MAX
							fDefaultChunkSizeParam = INT_MAX;
							// recompute buffer period
							fDefaultBufferPeriodParam =
									size_t(8000000/1024*fDefaultChunkSizeParam/fDefaultBitRateParam);
						} else {
							fDefaultChunkSizeParam = MAX(1,int32(value));
						}
						fDefaultChunkSizeParamChangeTime = fDefaultBufferPeriodParamChangeTime;
						chunkSizeUpdated = true;
					}
				}
			}
			break;
		default:
			PRINT("AbstractFileInterfaceNode::HandleParameter called with unknown param id (%ld)\n",param);
			status = B_ERROR;
	}
	// send updates out for all the parameters that changed
	// in every case this should be two updates. (if I have not made an error :-) )
	if (chunkSizeUpdated) {
		PRINT("\tchunk size parameter updated\n");
		BroadcastNewParameterValue(fDefaultChunkSizeParamChangeTime,
								   DEFAULT_CHUNK_SIZE_PARAM,
								   &fDefaultChunkSizeParam,
								   sizeof(fDefaultChunkSizeParam));
	}
	if (bitRateUpdated) {
		PRINT("\tbit rate parameter updated\n");
		BroadcastNewParameterValue(fDefaultBitRateParamChangeTime,
								   DEFAULT_BIT_RATE_PARAM,
								   &fDefaultBitRateParam,
								   sizeof(fDefaultBitRateParam));
	}
	if (bufferPeriodUpdated) {
		PRINT("\tbuffer period parameter updated\n");
		BroadcastNewParameterValue(fDefaultBufferPeriodParamChangeTime,
								   DEFAULT_BUFFER_PERIOD_PARAM,
								   &fDefaultBufferPeriodParam,
								   sizeof(fDefaultBufferPeriodParam));
	}
	return status;
}


// -------------------------------------------------------- //
// AbstractFileInterfaceNode specific functions
// -------------------------------------------------------- //
void AbstractFileInterfaceNode::GetFlavor(flavor_info * info, int32 id)
{
	CALLED();

	if (info == 0)
		return;

	info->name = strdup("AbstractFileInterfaceNode");
	info->info = strdup("A AbstractFileInterfaceNode node handles a file.");
	info->kinds = B_FILE_INTERFACE | B_CONTROLLABLE;
	info->flavor_flags = B_FLAVOR_IS_LOCAL;
	info->possible_count = INT_MAX;
	info->in_format_count = 0; // no inputs
	info->in_formats = 0;
	info->out_format_count = 0; // no outputs
	info->out_formats = 0;
	info->internal_id = id;
	return;
}


void AbstractFileInterfaceNode::GetFormat(media_format * outFormat)
{
	CALLED();

	if (outFormat == 0)
		return;

	outFormat->type = B_MEDIA_MULTISTREAM;
	outFormat->require_flags = B_MEDIA_MAUI_UNDEFINED_FLAGS;
	outFormat->deny_flags = B_MEDIA_MAUI_UNDEFINED_FLAGS;
	outFormat->u.multistream = media_multistream_format::wildcard;
}


void AbstractFileInterfaceNode::GetFileFormat(media_file_format * outFileFormat)
{
	CALLED();

	if (outFileFormat == 0)
		return;

	outFileFormat->capabilities =
			  media_file_format::B_PERFECTLY_SEEKABLE
			| media_file_format::B_IMPERFECTLY_SEEKABLE
			| media_file_format::B_KNOWS_ANYTHING;
	/* I don't know what to initialize this to. (or if I should) */
	// format.id =
	outFileFormat->family = B_ANY_FORMAT_FAMILY;
	outFileFormat->version = 100;
	// see media_file_format in <MediaDefs.h> for limits
	strncpy(outFileFormat->mime_type,"",63);
	outFileFormat->mime_type[63]='\0';
	strncpy(outFileFormat->pretty_name,"any media file format",63);
	outFileFormat->pretty_name[63]='\0';
	strncpy(outFileFormat->short_name,"any",31);
	outFileFormat->short_name[31]='\0';
	strncpy(outFileFormat->file_extension,"",7);
	outFileFormat->file_extension[7]='\0';
}


// protected:
// Here we make some guesses based on the file's mime type.
// We don't have enough information to add any other requirements.
// This function doesn't complain if you have already decided you want
// the stream to be considered a different one. (so you can say that you
// want to read that mpeg file as avi if you are so nutty.)
//
status_t AbstractFileInterfaceNode::AddRequirements(media_format * format)
{
	if (strcmp("video/x-msvideo",f_current_mime_type) == 0) {
		if (format->u.multistream.format == media_multistream_format::wildcard.format) {
			format->u.multistream.format = media_multistream_format::B_AVI;
		}
	} else
	if (strcmp("video/mpeg",f_current_mime_type) == 0) {
		if (format->u.multistream.format == media_multistream_format::wildcard.format) {
			format->u.multistream.format = media_multistream_format::B_MPEG1;
		}
	} else
	if (strcmp("video/quicktime",f_current_mime_type) == 0) {
		if (format->u.multistream.format == media_multistream_format::wildcard.format) {
			format->u.multistream.format = media_multistream_format::B_QUICKTIME;
		}
	} else
	if (strcmp("audio/x-mpeg",f_current_mime_type) == 0) {
		if (format->u.multistream.format == media_multistream_format::wildcard.format) {
			format->u.multistream.format = media_multistream_format::B_MPEG1;
		}
	}
	return B_OK;
}


// We need some sort of bit rate and chunk size, so if the other guy
// didn't care, we'll use our own defaults.
status_t AbstractFileInterfaceNode::ResolveWildcards(media_format * format)
{
	CALLED();
	// There isn't an unknown format. hmph.
	//	if (format->u.multistream.format == media_multistream_format::wildcard.format) {
	//		format->u.multistream.format = media_multistream_format::B_UNKNOWN;
	//	}
	if (format->u.multistream.max_bit_rate == media_multistream_format::wildcard.max_bit_rate) {
		format->u.multistream.max_bit_rate = fDefaultBitRateParam;
	}
	if (format->u.multistream.max_chunk_size == media_multistream_format::wildcard.max_chunk_size) {
		format->u.multistream.max_chunk_size = fDefaultChunkSizeParam;
	}
	if (format->u.multistream.avg_bit_rate == media_multistream_format::wildcard.avg_bit_rate) {
		format->u.multistream.avg_bit_rate = fDefaultBitRateParam;
	}
	if (format->u.multistream.avg_chunk_size == media_multistream_format::wildcard.avg_chunk_size) {
		format->u.multistream.avg_chunk_size = fDefaultChunkSizeParam;
	}
	return B_OK;
}


// -------------------------------------------------------- //
// stuffing
// -------------------------------------------------------- //
status_t AbstractFileInterfaceNode::_Reserved_AbstractFileInterfaceNode_0(void *) { return B_ERROR; }
status_t AbstractFileInterfaceNode::_Reserved_AbstractFileInterfaceNode_1(void *) { return B_ERROR; }
status_t AbstractFileInterfaceNode::_Reserved_AbstractFileInterfaceNode_2(void *) { return B_ERROR; }
status_t AbstractFileInterfaceNode::_Reserved_AbstractFileInterfaceNode_3(void *) { return B_ERROR; }
status_t AbstractFileInterfaceNode::_Reserved_AbstractFileInterfaceNode_4(void *) { return B_ERROR; }
status_t AbstractFileInterfaceNode::_Reserved_AbstractFileInterfaceNode_5(void *) { return B_ERROR; }
status_t AbstractFileInterfaceNode::_Reserved_AbstractFileInterfaceNode_6(void *) { return B_ERROR; }
status_t AbstractFileInterfaceNode::_Reserved_AbstractFileInterfaceNode_7(void *) { return B_ERROR; }
status_t AbstractFileInterfaceNode::_Reserved_AbstractFileInterfaceNode_8(void *) { return B_ERROR; }
status_t AbstractFileInterfaceNode::_Reserved_AbstractFileInterfaceNode_9(void *) { return B_ERROR; }
status_t AbstractFileInterfaceNode::_Reserved_AbstractFileInterfaceNode_10(void *) { return B_ERROR; }
status_t AbstractFileInterfaceNode::_Reserved_AbstractFileInterfaceNode_11(void *) { return B_ERROR; }
status_t AbstractFileInterfaceNode::_Reserved_AbstractFileInterfaceNode_12(void *) { return B_ERROR; }
status_t AbstractFileInterfaceNode::_Reserved_AbstractFileInterfaceNode_13(void *) { return B_ERROR; }
status_t AbstractFileInterfaceNode::_Reserved_AbstractFileInterfaceNode_14(void *) { return B_ERROR; }
status_t AbstractFileInterfaceNode::_Reserved_AbstractFileInterfaceNode_15(void *) { return B_ERROR; }