xref: /haiku/src/apps/mediaplayer/media_node_framework/video/VideoProducer.cpp (revision d0ac609964842f8cdb6d54b3c539c6c15293e172)
1 /*	Copyright (c) 1998-99, Be Incorporated, All Rights Reserved.
2  *	Distributed under the terms of the Be Sample Code license.
3  *
4  *	Copyright (c) 2000-2008, Ingo Weinhold <ingo_weinhold@gmx.de>,
5  *	Copyright (c) 2000-2008, Stephan Aßmus <superstippi@gmx.de>,
6  *	All Rights Reserved. Distributed under the terms of the MIT license.
7  */
8 
9 
10 #include "VideoProducer.h"
11 
12 #include <stdio.h>
13 #include <string.h>
14 
15 #include <Autolock.h>
16 #include <Buffer.h>
17 #include <BufferGroup.h>
18 #include <TimeSource.h>
19 
20 #include "NodeManager.h"
21 #include "VideoSupplier.h"
22 
23 
24 // debugging
25 //#define TRACE_VIDEO_PRODUCER
26 #ifdef TRACE_VIDEO_PRODUCER
27 # define	TRACE(x...) printf("VideoProducer::"); printf(x)
28 # define	FUNCTION(x...) TRACE(x)
29 # define	ERROR(x...) fprintf(stderr, "VideoProducer::"); fprintf(stderr, x)
30 #else
31 # define	TRACE(x...)
32 # define	FUNCTION(x...)
33 # define	ERROR(x...) fprintf(stderr, "VideoProducer::"); fprintf(stderr, x)
34 #endif
35 
36 
37 #define BUFFER_COUNT 3
38 
39 #define TOUCH(x) ((void)(x))
40 
41 
42 VideoProducer::VideoProducer(BMediaAddOn* addon, const char* name,
43 		int32 internalId, NodeManager* manager, VideoSupplier* supplier)
44 	: BMediaNode(name),
45 	  BMediaEventLooper(),
46 	  BBufferProducer(B_MEDIA_RAW_VIDEO),
47 	  fInitStatus(B_NO_INIT),
48 	  fInternalID(internalId),
49 	  fAddOn(addon),
50 	  fBufferGroup(NULL),
51 	  fUsedBufferGroup(NULL),
52 	  fThread(-1),
53 	  fFrameSync(-1),
54 	  fFrame(0),
55 	  fFrameBase(0),
56 	  fPerformanceTimeBase(0),
57 	  fBufferLatency(0),
58 	  fRunning(false),
59 	  fConnected(false),
60 	  fEnabled(false),
61 	  fManager(manager),
62 	  fSupplier(supplier)
63 {
64 	fOutput.destination = media_destination::null;
65 	fInitStatus = B_OK;
66 }
67 
68 
69 VideoProducer::~VideoProducer()
70 {
71 	if (fInitStatus == B_OK) {
72 		// Clean up after ourselves, in case the application didn't make us
73 		// do so.
74 		if (fConnected)
75 			Disconnect(fOutput.source, fOutput.destination);
76 		if (fRunning)
77 			_HandleStop();
78 	}
79 	Quit();
80 }
81 
82 
83 BMediaAddOn*
84 VideoProducer::AddOn(int32* _internalId) const
85 {
86 	if (_internalId)
87 		*_internalId = fInternalID;
88 	return fAddOn;
89 }
90 
91 
92 status_t
93 VideoProducer::HandleMessage(int32 message, const void* data, size_t size)
94 {
95 	return B_ERROR;
96 }
97 
98 
99 void
100 VideoProducer::SetTimeSource(BTimeSource* timeSource)
101 {
102 	// Tell frame generation thread to recalculate delay value
103 	release_sem(fFrameSync);
104 }
105 
106 
107 void
108 VideoProducer::NodeRegistered()
109 {
110 	if (fInitStatus != B_OK) {
111 		ReportError(B_NODE_IN_DISTRESS);
112 		return;
113 	}
114 
115 	fOutput.node = Node();
116 	fOutput.source.port = ControlPort();
117 	fOutput.source.id = 0;
118 	fOutput.destination = media_destination::null;
119 	strcpy(fOutput.name, Name());
120 
121 	// fill with wild cards at this point in time
122 	fOutput.format.type = B_MEDIA_RAW_VIDEO;
123 	fOutput.format.u.raw_video = media_raw_video_format::wildcard;
124 	fOutput.format.u.raw_video.interlace = 1;
125 	fOutput.format.u.raw_video.display.format = B_NO_COLOR_SPACE;
126 	fOutput.format.u.raw_video.display.bytes_per_row = 0;
127 	fOutput.format.u.raw_video.display.line_width = 0;
128 	fOutput.format.u.raw_video.display.line_count = 0;
129 
130 	// start the BMediaEventLooper control loop running
131 	Run();
132 }
133 
134 
135 void
136 VideoProducer::Start(bigtime_t performanceTime)
137 {
138 	// notify the manager in case we were started from the outside world
139 //	fManager->StartPlaying();
140 
141 	BMediaEventLooper::Start(performanceTime);
142 }
143 
144 
145 void
146 VideoProducer::Stop(bigtime_t performanceTime, bool immediate)
147 {
148 	// notify the manager in case we were stopped from the outside world
149 //	fManager->StopPlaying();
150 
151 	BMediaEventLooper::Stop(performanceTime, immediate);
152 }
153 
154 
155 void
156 VideoProducer::Seek(bigtime_t media_time, bigtime_t performanceTime)
157 {
158 	BMediaEventLooper::Seek(media_time, performanceTime);
159 }
160 
161 
162 void
163 VideoProducer::HandleEvent(const media_timed_event* event,
164 		bigtime_t lateness, bool realTimeEvent)
165 {
166 	TOUCH(lateness); TOUCH(realTimeEvent);
167 
168 	switch (event->type) {
169 		case BTimedEventQueue::B_START:
170 			_HandleStart(event->event_time);
171 			break;
172 		case BTimedEventQueue::B_STOP:
173 		{
174 			EventQueue()->FlushEvents(event->event_time,
175 				BTimedEventQueue::B_ALWAYS,
176 				true, BTimedEventQueue::B_HANDLE_BUFFER);
177 			_HandleStop();
178 			break;
179 		}
180 		case BTimedEventQueue::B_WARP:
181 			_HandleTimeWarp(event->bigdata);
182 			break;
183 		case BTimedEventQueue::B_SEEK:
184 			_HandleSeek(event->bigdata);
185 			break;
186 		case BTimedEventQueue::B_HANDLE_BUFFER:
187 		case BTimedEventQueue::B_DATA_STATUS:
188 		case BTimedEventQueue::B_PARAMETER:
189 		default:
190 			TRACE("HandleEvent: Unhandled event -- %lx\n", event->type);
191 			break;
192 	}
193 }
194 
195 
196 status_t
197 VideoProducer::DeleteHook(BMediaNode* node)
198 {
199 	return BMediaEventLooper::DeleteHook(node);
200 }
201 
202 
203 status_t
204 VideoProducer::FormatSuggestionRequested(media_type type, int32 quality,
205 	media_format* _format)
206 {
207 	FUNCTION("FormatSuggestionRequested\n");
208 
209 	if (type != B_MEDIA_ENCODED_VIDEO)
210 		return B_MEDIA_BAD_FORMAT;
211 
212 	TOUCH(quality);
213 
214 	*_format = fOutput.format;
215 	return B_OK;
216 }
217 
218 
219 status_t
220 VideoProducer::FormatProposal(const media_source& output, media_format* format)
221 {
222 	#ifdef TRACE_VIDEO_PRODUCER
223 		char string[256];
224 		string_for_format(*format, string, 256);
225 		FUNCTION("FormatProposal(%s)\n", string);
226 	#endif
227 
228 	if (!format)
229 		return B_BAD_VALUE;
230 
231 	if (output != fOutput.source)
232 		return B_MEDIA_BAD_SOURCE;
233 
234 	status_t ret = format_is_compatible(*format, fOutput.format) ?
235 		B_OK : B_MEDIA_BAD_FORMAT;
236 	if (ret != B_OK) {
237 		ERROR("FormatProposal() error: %s\n", strerror(ret));
238 		char string[512];
239 		string_for_format(*format, string, sizeof(string));
240 		ERROR("  requested: %s\n", string);
241 		string_for_format(fOutput.format, string, sizeof(string));
242 		ERROR("  output:    %s\n", string);
243 	}
244 
245 	// change any wild cards to specific values
246 
247 	return ret;
248 
249 }
250 
251 
252 status_t
253 VideoProducer::FormatChangeRequested(const media_source& source,
254 	const media_destination& destination, media_format* ioFormat,
255 	int32 *_deprecated_)
256 {
257 	TOUCH(destination); TOUCH(ioFormat); TOUCH(_deprecated_);
258 
259 	if (source != fOutput.source)
260 		return B_MEDIA_BAD_SOURCE;
261 
262 	return B_ERROR;
263 }
264 
265 
266 status_t
267 VideoProducer::GetNextOutput(int32* cookie, media_output* outOutput)
268 {
269 	if (!outOutput)
270 		return B_BAD_VALUE;
271 
272 	if ((*cookie) != 0)
273 		return B_BAD_INDEX;
274 
275 	*outOutput = fOutput;
276 	(*cookie)++;
277 
278 	return B_OK;
279 }
280 
281 
282 status_t
283 VideoProducer::DisposeOutputCookie(int32 cookie)
284 {
285 	TOUCH(cookie);
286 
287 	return B_OK;
288 }
289 
290 
291 status_t
292 VideoProducer::SetBufferGroup(const media_source& forSource,
293 	BBufferGroup *group)
294 {
295 	if (forSource != fOutput.source)
296 		return B_MEDIA_BAD_SOURCE;
297 
298 	TRACE("VideoProducer::SetBufferGroup() - using buffer group of "
299 		"consumer.\n");
300 	fUsedBufferGroup = group;
301 
302 	return B_OK;
303 }
304 
305 
306 status_t
307 VideoProducer::VideoClippingChanged(const media_source& forSource,
308 	int16 numShorts, int16* clipData, const media_video_display_info& display,
309 	int32* _deprecated_)
310 {
311 	TOUCH(forSource); TOUCH(numShorts); TOUCH(clipData);
312 	TOUCH(display); TOUCH(_deprecated_);
313 
314 	return B_ERROR;
315 }
316 
317 
318 status_t
319 VideoProducer::GetLatency(bigtime_t* _latency)
320 {
321 	if (!_latency)
322 		return B_BAD_VALUE;
323 
324 	*_latency = EventLatency() + SchedulingLatency();
325 
326 	return B_OK;
327 }
328 
329 
330 status_t
331 VideoProducer::PrepareToConnect(const media_source& source,
332 	const media_destination& destination, media_format* format,
333 	media_source* outSource, char* outName)
334 {
335 	FUNCTION("PrepareToConnect() %ldx%ld\n",
336 		format->u.raw_video.display.line_width,
337 		format->u.raw_video.display.line_count);
338 
339 	if (fConnected) {
340 		ERROR("PrepareToConnect() - already connected!\n");
341 		return B_MEDIA_ALREADY_CONNECTED;
342 	}
343 
344 	if (source != fOutput.source)
345 		return B_MEDIA_BAD_SOURCE;
346 
347 	if (fOutput.destination != media_destination::null) {
348 		ERROR("PrepareToConnect() - destination != null.\n");
349 		return B_MEDIA_ALREADY_CONNECTED;
350 	}
351 
352 	// The format parameter comes in with the suggested format, and may be
353 	// specialized as desired by the node
354 	if (!format_is_compatible(*format, fOutput.format)) {
355 		ERROR("PrepareToConnect() - incompatible format.\n");
356 		*format = fOutput.format;
357 		return B_MEDIA_BAD_FORMAT;
358 	}
359 
360 	if (format->u.raw_video.display.line_width == 0)
361 		format->u.raw_video.display.line_width = 384;
362 	if (format->u.raw_video.display.line_count == 0)
363 		format->u.raw_video.display.line_count = 288;
364 	if (format->u.raw_video.field_rate == 0)
365 		format->u.raw_video.field_rate = 25.0;
366 	if (format->u.raw_video.display.bytes_per_row == 0)
367 		format->u.raw_video.display.bytes_per_row = format->u.raw_video.display.line_width * 4;
368 
369 	*outSource = fOutput.source;
370 	strcpy(outName, fOutput.name);
371 
372 	return B_OK;
373 }
374 
375 
376 void
377 VideoProducer::Connect(status_t error, const media_source& source,
378 	const media_destination& destination, const media_format& format,
379 	char* _name)
380 {
381 	FUNCTION("Connect() %ldx%ld\n",
382 		format.u.raw_video.display.line_width,
383 		format.u.raw_video.display.line_count);
384 
385 	if (fConnected) {
386 		ERROR("Connect() - already connected.\n");
387 		return;
388 	}
389 
390 	if (source != fOutput.source) {
391 		ERROR("Connect() - wrong source.\n");
392 		return;
393 	}
394 	if (error != B_OK) {
395 		ERROR("Connect() - consumer error: %s\n", strerror(error));
396 		return;
397 	}
398 	if (!const_cast<media_format*>(&format)->Matches(&fOutput.format)) {
399 		ERROR("Connect() - format mismatch.\n");
400 		return;
401 	}
402 
403 	fOutput.destination = destination;
404 	strcpy(_name, fOutput.name);
405 	fConnectedFormat = format.u.raw_video;
406 	fBufferDuration = 20000;
407 
408 	if (fConnectedFormat.field_rate != 0.0f) {
409 		fPerformanceTimeBase = fPerformanceTimeBase
410 			+ (bigtime_t)((fFrame - fFrameBase)
411 				* 1000000LL / fConnectedFormat.field_rate);
412 		fFrameBase = fFrame;
413 		fBufferDuration = bigtime_t(1000000LL / fConnectedFormat.field_rate);
414 	}
415 
416 	if (fConnectedFormat.display.bytes_per_row == 0) {
417 		ERROR("Connect() - connected format still has BPR wildcard!\n");
418 		fConnectedFormat.display.bytes_per_row
419 			= 4 * fConnectedFormat.display.line_width;
420 	}
421 
422 	// Create the buffer group
423 	if (fUsedBufferGroup == NULL) {
424 		fBufferGroup = new BBufferGroup(fConnectedFormat.display.bytes_per_row
425 			* fConnectedFormat.display.line_count, BUFFER_COUNT);
426 		status_t err = fBufferGroup->InitCheck();
427 		if (err < B_OK) {
428 			delete fBufferGroup;
429 			fBufferGroup = NULL;
430 			ERROR("Connect() - buffer group error: %s\n", strerror(err));
431 			return;
432 		}
433 		fUsedBufferGroup = fBufferGroup;
434 	}
435 
436 	// get the latency
437 	fBufferLatency = (BUFFER_COUNT - 1) * fBufferDuration;
438 
439 	int32 bufferCount;
440 	if (fUsedBufferGroup->CountBuffers(&bufferCount) == B_OK) {
441 		// recompute the latency
442 		fBufferLatency = (bufferCount - 1) * fBufferDuration;
443 	}
444 
445 	bigtime_t latency = 0;
446 	media_node_id tsID = 0;
447 	FindLatencyFor(fOutput.destination, &latency, &tsID);
448 	SetEventLatency(latency + fBufferLatency);
449 
450 	fConnected = true;
451 	fEnabled = true;
452 
453 	// Tell frame generation thread to recalculate delay value
454 	release_sem(fFrameSync);
455 }
456 
457 
458 void
459 VideoProducer::Disconnect(const media_source& source,
460 	const media_destination& destination)
461 {
462 	FUNCTION("Disconnect()\n");
463 
464 	if (!fConnected) {
465 		ERROR("Disconnect() - Not connected\n");
466 		return;
467 	}
468 
469 	if ((source != fOutput.source) || (destination != fOutput.destination)) {
470 		ERROR("Disconnect() - Bad source and/or destination\n");
471 		return;
472 	}
473 
474 	fEnabled = false;
475 	fOutput.destination = media_destination::null;
476 
477 	if (fLock.Lock()) {
478 		// Always delete the buffer group, even if it is not ours.
479 		// (See BeBook::SetBufferGroup()).
480 		delete fUsedBufferGroup;
481 		if (fBufferGroup != fUsedBufferGroup)
482 			delete fBufferGroup;
483 		fUsedBufferGroup = NULL;
484 		fBufferGroup = NULL;
485 		fLock.Unlock();
486 	}
487 
488 	fConnected = false;
489 	TRACE("Disconnect() done\n");
490 }
491 
492 
493 void
494 VideoProducer::LateNoticeReceived(const media_source &source,
495 		bigtime_t how_much, bigtime_t performanceTime)
496 {
497 	TOUCH(source); TOUCH(how_much); TOUCH(performanceTime);
498 	TRACE("Late!!!\n");
499 }
500 
501 
502 void
503 VideoProducer::EnableOutput(const media_source& source, bool enabled,
504 	int32* _deprecated_)
505 {
506 	TOUCH(_deprecated_);
507 
508 	if (source != fOutput.source)
509 		return;
510 
511 	fEnabled = enabled;
512 }
513 
514 
515 status_t
516 VideoProducer::SetPlayRate(int32 numer, int32 denom)
517 {
518 	TOUCH(numer); TOUCH(denom);
519 
520 	return B_ERROR;
521 }
522 
523 
524 void
525 VideoProducer::AdditionalBufferRequested(const media_source& source,
526 	media_buffer_id prevBuffer, bigtime_t prevTime,
527 	const media_seek_tag* prevTag)
528 {
529 	TOUCH(source); TOUCH(prevBuffer); TOUCH(prevTime); TOUCH(prevTag);
530 }
531 
532 
533 void
534 VideoProducer::LatencyChanged(const media_source& source,
535 	const media_destination& destination,
536 	bigtime_t newLatency, uint32 flags)
537 {
538 	TOUCH(source); TOUCH(destination); TOUCH(newLatency); TOUCH(flags);
539 	TRACE("Latency changed!\n");
540 }
541 
542 
543 // #pragma mark -
544 
545 
546 void
547 VideoProducer::_HandleStart(bigtime_t performanceTime)
548 {
549 	// Start producing frames, even if the output hasn't been connected yet.
550 	TRACE("_HandleStart(%Ld)\n", performanceTime);
551 
552 	if (fRunning) {
553 		TRACE("_HandleStart: Node already started\n");
554 		return;
555 	}
556 
557 	fFrame = 0;
558 	fFrameBase = 0;
559 	fPerformanceTimeBase = performanceTime;
560 
561 	fFrameSync = create_sem(0, "frame synchronization");
562 	if (fFrameSync < B_OK)
563 		return;
564 
565 	fThread = spawn_thread(_FrameGeneratorThreadEntry, "frame generator",
566 		B_NORMAL_PRIORITY, this);
567 	if (fThread < B_OK) {
568 		delete_sem(fFrameSync);
569 		return;
570 	}
571 
572 	resume_thread(fThread);
573 	fRunning = true;
574 	return;
575 }
576 
577 
578 void
579 VideoProducer::_HandleStop()
580 {
581 	TRACE("_HandleStop()\n");
582 
583 	if (!fRunning) {
584 		TRACE("_HandleStop: Node isn't running\n");
585 		return;
586 	}
587 
588 	delete_sem(fFrameSync);
589 	wait_for_thread(fThread, &fThread);
590 
591 	fRunning = false;
592 }
593 
594 
595 void
596 VideoProducer::_HandleTimeWarp(bigtime_t performanceTime)
597 {
598 	fPerformanceTimeBase = performanceTime;
599 	fFrameBase = fFrame;
600 
601 	// Tell frame generation thread to recalculate delay value
602 	release_sem(fFrameSync);
603 }
604 
605 
606 void
607 VideoProducer::_HandleSeek(bigtime_t performanceTime)
608 {
609 	fPerformanceTimeBase = performanceTime;
610 	fFrameBase = fFrame;
611 
612 	// Tell frame generation thread to recalculate delay value
613 	release_sem(fFrameSync);
614 }
615 
616 
617 int32
618 VideoProducer::_FrameGeneratorThreadEntry(void* data)
619 {
620 	return ((VideoProducer*)data)->_FrameGeneratorThread();
621 }
622 
623 
624 int32
625 VideoProducer::_FrameGeneratorThread()
626 {
627 	bool forceSendingBuffer = true;
628 	int32 droppedFrames = 0;
629 	const int32 kMaxDroppedFrames = 15;
630 	bool running = true;
631 	while (running) {
632 		TRACE("_FrameGeneratorThread: loop: %Ld\n", fFrame);
633 		// lock the node manager
634 		status_t err = fManager->LockWithTimeout(10000);
635 		bool ignoreEvent = false;
636 		// Data to be retrieved from the node manager.
637 		bigtime_t performanceTime = 0;
638 		bigtime_t nextPerformanceTime = 0;
639 		bigtime_t waitUntil = 0;
640 		bigtime_t nextWaitUntil = 0;
641 		int32 playingDirection = 0;
642 		int64 playlistFrame = 0;
643 		switch (err) {
644 			case B_OK: {
645 				TRACE("_FrameGeneratorThread: node manager successfully "
646 					"locked\n");
647 				if (droppedFrames > 0)
648 					fManager->FrameDropped();
649 				// get the times for the current and the next frame
650 				performanceTime = fManager->TimeForFrame(fFrame);
651 				nextPerformanceTime = fManager->TimeForFrame(fFrame + 1);
652 				waitUntil = TimeSource()->RealTimeFor(fPerformanceTimeBase
653 					+ performanceTime, fBufferLatency);
654 				nextWaitUntil = TimeSource()->RealTimeFor(fPerformanceTimeBase
655 					+ nextPerformanceTime, fBufferLatency);
656 				// get playing direction and playlist frame for the current
657 				// frame
658 				bool newPlayingState;
659 				playlistFrame = fManager->PlaylistFrameAtFrame(fFrame,
660 					playingDirection, newPlayingState);
661 				TRACE("_FrameGeneratorThread: performance time: %Ld, "
662 					"playlist frame: %lld\n", performanceTime, playlistFrame);
663 				forceSendingBuffer |= newPlayingState;
664 				fManager->SetCurrentVideoTime(nextPerformanceTime);
665 				fManager->Unlock();
666 				break;
667 			}
668 			case B_TIMED_OUT:
669 				TRACE("_FrameGeneratorThread: Couldn't lock the node "
670 					"manager.\n");
671 				ignoreEvent = true;
672 				waitUntil = system_time() - 1;
673 				break;
674 			default:
675 				ERROR("_FrameGeneratorThread: Couldn't lock the node manager. "
676 					"Terminating video producer frame generator thread.\n");
677 				TRACE("_FrameGeneratorThread: frame generator thread done.\n");
678 				// do not access any member variables, since this could
679 				// also mean the Node has been deleted
680 				return B_OK;
681 		}
682 
683 		TRACE("_FrameGeneratorThread: waiting (%Ld)...\n", waitUntil);
684 		// wait until...
685 		err = acquire_sem_etc(fFrameSync, 1, B_ABSOLUTE_TIMEOUT, waitUntil);
686 		// The only acceptable responses are B_OK and B_TIMED_OUT. Everything
687 		// else means the thread should quit. Deleting the semaphore, as in
688 		// VideoProducer::_HandleStop(), will trigger this behavior.
689 		switch (err) {
690 			case B_OK:
691 				TRACE("_FrameGeneratorThread: going back to sleep.\n");
692 				break;
693 			case B_TIMED_OUT:
694 				TRACE("_FrameGeneratorThread: timed out => event\n");
695 				// Catch the cases in which the node manager could not be
696 				// locked and we therefore have no valid data to work with,
697 				// or the producer is not running or enabled.
698 				if (ignoreEvent || !fRunning || !fEnabled) {
699 					TRACE("_FrameGeneratorThread: ignore event\n");
700 					// nothing to do
701 				} else if (!forceSendingBuffer
702 					&& nextWaitUntil < system_time() - fBufferLatency
703 					&& droppedFrames < kMaxDroppedFrames) {
704 					// Drop frame if it's at least a frame late.
705 					if (playingDirection > 0) {
706 						printf("VideoProducer: dropped frame (%" B_PRId64
707 							") (perf. time %" B_PRIdBIGTIME ")\n", fFrame,
708 							performanceTime);
709 					}
710 					// next frame
711 					droppedFrames++;
712 					fFrame++;
713 				} else if (playingDirection != 0 || forceSendingBuffer) {
714 					// Send buffers only, if playing, the node is running and
715 					// the output has been enabled
716 					TRACE("_FrameGeneratorThread: produce frame\n");
717 					BAutolock _(fLock);
718 					// Fetch a buffer from the buffer group
719 					fUsedBufferGroup->WaitForBuffers();
720 					BBuffer* buffer = fUsedBufferGroup->RequestBuffer(
721 						fConnectedFormat.display.bytes_per_row
722 						* fConnectedFormat.display.line_count, 0LL);
723 					if (buffer == NULL) {
724 						// Wait until a buffer becomes available again
725 						ERROR("_FrameGeneratorThread: no buffer!\n");
726 						break;
727 					}
728 					// Fill out the details about this buffer.
729 					media_header* h = buffer->Header();
730 					h->type = B_MEDIA_RAW_VIDEO;
731 					h->time_source = TimeSource()->ID();
732 					h->size_used = fConnectedFormat.display.bytes_per_row
733 						* fConnectedFormat.display.line_count;
734 					// For a buffer originating from a device, you might
735 					// want to calculate this based on the
736 					// PerformanceTimeFor the time your buffer arrived at
737 					// the hardware (plus any applicable adjustments).
738 					h->start_time = fPerformanceTimeBase + performanceTime;
739 					h->file_pos = 0;
740 					h->orig_size = 0;
741 					h->data_offset = 0;
742 					h->u.raw_video.field_gamma = 1.0;
743 					h->u.raw_video.field_sequence = fFrame;
744 					h->u.raw_video.field_number = 0;
745 					h->u.raw_video.pulldown_number = 0;
746 					h->u.raw_video.first_active_line = 1;
747 					h->u.raw_video.line_count
748 						= fConnectedFormat.display.line_count;
749 					// Fill in a frame
750 					TRACE("_FrameGeneratorThread: frame: %Ld, "
751 						"playlistFrame: %Ld\n", fFrame, playlistFrame);
752 					bool wasCached = false;
753 					err = fSupplier->FillBuffer(playlistFrame,
754 						buffer->Data(), fConnectedFormat, forceSendingBuffer,
755 						wasCached);
756 					if (err == B_TIMED_OUT) {
757 						// Don't send the buffer if there was insufficient
758 						// time for rendering, this will leave the last
759 						// valid frame on screen until we catch up, instead
760 						// of going black.
761 						wasCached = true;
762 						err = B_OK;
763 					}
764 					// clean the buffer if something went wrong
765 					if (err != B_OK) {
766 						// TODO: should use "back value" according
767 						// to color space!
768 						memset(buffer->Data(), 0, h->size_used);
769 						err = B_OK;
770 					}
771 					// Send the buffer on down to the consumer
772 					if (wasCached || (err = SendBuffer(buffer, fOutput.source,
773 							fOutput.destination) != B_OK)) {
774 						// If there is a problem sending the buffer,
775 						// or if we don't send the buffer because its
776 						// contents are the same as the last one,
777 						// return it to its buffer group.
778 						buffer->Recycle();
779 						// we tell the supplier to delete
780 						// its caches if there was a problem sending
781 						// the buffer
782 						if (err != B_OK) {
783 							ERROR("_FrameGeneratorThread: Error "
784 								"sending buffer\n");
785 							fSupplier->DeleteCaches();
786 						}
787 					}
788 					// Only if everything went fine we clear the flag
789 					// that forces us to send a buffer even if not
790 					// playing.
791 					if (err == B_OK)
792 						forceSendingBuffer = false;
793 					// next frame
794 					fFrame++;
795 					droppedFrames = 0;
796 				} else {
797 					TRACE("_FrameGeneratorThread: not playing\n");
798 					// next frame
799 					fFrame++;
800 				}
801 				break;
802 			default:
803 				TRACE("_FrameGeneratorThread: Couldn't acquire semaphore. "
804 					"Error: %s\n", strerror(err));
805 				running = false;
806 				break;
807 		}
808 	}
809 	TRACE("_FrameGeneratorThread: frame generator thread done.\n");
810 	return B_OK;
811 }
812 
813