device: add option to start audio immediately at fast channel switch

Author: rellla

README.md

@@ -204,8 +204,9 @@ Setup: /etc/vdr/setup.conf
 		     Same as above, but now the display also chooses an interlaced mode for interlaced input (except for 576i) if available
 
 	softhddevice-drm-gles.VideoFastChannelSwitch = 0
-		0 = enable fast channel switch: the first available frame is displayed as a still-picture as soon as possible until a/v is in sync
-		1 = fast channel switch is disabled
+		0 = fast channel switch is disabled
+		1 = enable fast channel switch: video is presented immediately as a still-picture
+		2 = enable fast channel switch: video is presented immediately as a still-picture and audio starts as soon as possible (slower than 1)
 
 	softhddevice-drm-gles.MaxSizeGPUImageCache = 128
 		how many GPU memory should be used for image caching

config.h

@@ -58,7 +58,7 @@ class cSoftHdConfig {
 	// Video
 	int ConfigVideoEnableHDR = 0;               ///< enable HDR
 	int ConfigVideoDisplayMode = CONFIG_DISPLAY_MODE_DEFAULT; ///< display mode (enum ConfigDisplayMode)
-	bool ConfigVideoFastChannelSwitch = false;  ///< first video frame is presented as still-picture as soon as possible
+	int ConfigVideoFastChannelSwitch = 0;       ///< fast channel switch mode (0: disabled, 1: video, 2: video + audio)
 
 	// Audio
 	bool ConfigAudioSoftvol = false;            ///< config use software volume

po/de_DE.po

@@ -362,6 +362,12 @@ msgstr "an Video angepasst (interlaced) %dx%d@%.2f%s"
 msgid "match video (interlaced)"
 msgstr "an Video anpassen (interlaced)"
 
+msgid "video"
+msgstr "Video"
+
+msgid "video and audio"
+msgstr "Video und Audio"
+
 #, c-format
 msgid "channel switch done in %ldms (%ldms)"
 msgstr "Kanal gewechselt in %ldms (%ldms)"

softhddevice.cpp

@@ -419,6 +419,11 @@ int cSoftHdDevice::PlayAudio(const uchar *data, int size, uchar id)
 	if (IsBufferingThresholdReached())
 		TriggerEvent(BufferingThresholdReachedEvent{});
 
+	// unpause audio, if the fast channel switch modes wants it to be started
+	// the audio buffer reached the threshold and we are in live tv mode
+	if (m_fastChannelSwitch == 2 && Transferring() && m_pAudio->IsPaused() && IsAudioBufferingThresholdReached())
+		m_pAudio->SetPaused(false);
+
 	AVPacket *avpkt;
 	do {
 		if (!(avpkt = m_audioReassemblyBuffer.PopAvPacket()))
@@ -952,12 +957,16 @@ bool cSoftHdDevice::IsBufferingThresholdReached()
 	int64_t syncedAudioBufferFillLevelMs = m_pAudio->GetInputPtsMs() - GetFirstAudioPtsMsToPlay();
 	int64_t syncedVideoBufferFillLevelMs = m_pVideoStream->GetInputPtsMs() - GetFirstVideoPtsMsToPlay();
 
+	int audioBehindVideo = m_pRender->GetOutputPtsMs() - m_pAudio->GetOutputPtsMs() - GetVideoAudioDelayMs();
+	bool audioReachedVideo = audioBehindVideo <= 0;
+
 	bool reached = m_pRender->IsOutputBufferFull() && // video decoder output buffer (audio hardware output buffer is negligible)
 		syncedVideoBufferFillLevelMs > GetBufferFillLevelThresholdMs() && // video decoder input buffer
-		syncedAudioBufferFillLevelMs > GetBufferFillLevelThresholdMs(); // audio decoder output buffer
+		syncedAudioBufferFillLevelMs > GetBufferFillLevelThresholdMs() && // audio decoder output buffer
+		(m_fastChannelSwitch == 2 ? audioReachedVideo : true); // if fast channel switch played audio already, wait for audio to come up
 
 	if (reached) {
-		LOGDEBUG2(L_AV_SYNC, "First received PTS: %s (audio), %s (video) buffer fill levels: %ldms (audio) %ldms (video)",
+		LOGDEBUG2(L_AV_SYNC, "buffering threshold reached - PTS: %s (audio), %s (video) - buffer fill levels: %ldms (audio) %ldms (video)",
 			Timestamp2String(m_pAudio->GetOutputPtsMs(), 1),
 			Timestamp2String(m_pRender->GetOutputPtsMs(), 1),
 			syncedAudioBufferFillLevelMs,
@@ -967,6 +976,40 @@ bool cSoftHdDevice::IsBufferingThresholdReached()
 	return reached;
 }
 
+/**
+ * Returns true, if audio buffer is filled enough to start audio playback
+ *
+ * @retval true    if audio playback should start
+ * @retval false   if audio playback should not start
+ *
+ * @note Used for fast channel switch
+ */
+bool cSoftHdDevice::IsAudioBufferingThresholdReached()
+{
+	if (m_pStateMachine->GetState() != BUFFERING)
+		return false;
+
+	bool audioHasInputPts = m_pAudio->HasInputPts();
+	bool videoHasInputPts = m_pVideoStream->HasInputPts();
+	bool videoHasOutputPts = m_pRender->GetOutputPtsMs() != AV_NOPTS_VALUE;
+
+	// only start audio playback, if video is already there
+	if (!audioHasInputPts || !videoHasInputPts || !videoHasOutputPts)
+		return false;
+
+	int64_t audioBufferFillLevelMs = m_pAudio->GetInputPtsMs() - m_pAudio->GetOutputPtsMs();
+	if (audioBufferFillLevelMs > GetBufferFillLevelThresholdMs()) {
+		LOGDEBUG2(L_AV_SYNC, "audio buffer reached threshold %dms - PTS: %s (audio), %s (video) - buffer fill levels: %ldms (audio)",
+			GetBufferFillLevelThresholdMs(),
+			Timestamp2String(m_pAudio->GetOutputPtsMs(), 1),
+			Timestamp2String(m_pRender->GetOutputPtsMs(), 1),
+			audioBufferFillLevelMs);
+		return true;
+	}
+
+	return false;
+}
+
 /*********************************************************************
  * cSoftHdDevice public API - osd control
  ********************************************************************/
@@ -1819,11 +1862,14 @@ bool cSoftHdDevice::SchedulePlaybackStart(void)
 
 	if (receivedAudio && receivedVideo) {
 		m_playbackMode = AUDIO_AND_VIDEO;
+		// store the first PTSes beforehand, because dropping samples/frames will change the output of GetFirst*PtsMsToPlay()
 		int64_t firstAudioPtsMs = GetFirstAudioPtsMsToPlay();
 		int64_t firstVideoPtsMs = GetFirstVideoPtsMsToPlay();
 
-		// store the first PTSes beforehand, because dropping samples/frames will change the output of GetFirst*PtsMsToPlay()
-		m_pAudio->DropSamplesOlderThanPtsMs(firstAudioPtsMs);
+		// don't drop old audio, if we want to wait for it in fast channel switch mode including audio playback
+		if (m_fastChannelSwitch < 2 || !Transferring())
+			m_pAudio->DropSamplesOlderThanPtsMs(firstAudioPtsMs);
+
 		m_pRender->SchedulePlaybackStartAtPtsMs(firstVideoPtsMs);
 	} else if (receivedAudio) {
 		LOGDEBUG("device: audio only detected");

softhddevice.h

@@ -147,9 +147,10 @@ class cSoftHdDevice : public cDevice, public cStatus {
 	void SetParseH264Dimensions(void);
 	void SetDecoderFallbackToSw(bool);
 	void SetEnableHdr(bool);
-	void SetEnableFastChannelSwitch(bool enable) { m_fastChannelSwitch = enable; };
+	void SetEnableFastChannelSwitch(int mode) { m_fastChannelSwitch = mode; };
 	void SetDisplayMode(int);
 	bool IsBufferingThresholdReached(void);
+	bool IsAudioBufferingThresholdReached(void);
 	bool IsVideoOnlyPlayback(void) { return m_playbackMode == VIDEO_ONLY; };
 
 	// Osd
@@ -257,7 +258,7 @@ class cSoftHdDevice : public cDevice, public cStatus {
 	cJitterTracker m_videoJitterTracker{"video"};   ///< video jitter tracker
 	std::chrono::steady_clock::time_point m_channelSwitchStartTime; ///< timestamp, when VDR triggered a channel switch
 	std::chrono::steady_clock::time_point m_dataReceivedTime;       ///< timestamp, when the first audio or video data after a channel switch arrives in Play*()
-	bool m_fastChannelSwitch = false;               ///< enable fast channel switch: display a video frame as still frame asap after stream start
+	int m_fastChannelSwitch = 0;                    ///< 0: fast channel switch disabled, 1: video start immediately, 2: video and audio start immediately
 
 	std::atomic<PlaybackMode> m_playbackMode = NONE; ///< current playback mode
 	int m_audioChannelID = -1;       ///< current audio channel ID

softhdsetupmenu.cpp

@@ -77,7 +77,8 @@ void cMenuSetupSoft::Create(void)
 	if (m_cVideoMenu) {
 		Add(new cMenuEditBoolItem(tr(" Enable HDR"), &m_cVideoEnableHDR, trVDR("no"), trVDR("yes")));
 		Add(new cMenuEditStraItem(tr(" Display mode"), &m_cVideoDisplayMode, m_displayModePtrs.size(), m_displayModePtrs.data()));
-		Add(new cMenuEditBoolItem(tr(" Enable fast channel switch"), &m_cVideoFastChannelSwitch, trVDR("no"), trVDR("yes")));
+
+		Add(new cMenuEditStraItem(tr(" Enable fast channel switch"), &m_cVideoFastChannelSwitch, m_fastChannelSwitchModePtrs.size(), m_fastChannelSwitchModePtrs.data()));
 	}
 
 	//
@@ -301,6 +302,7 @@ cMenuSetupSoft::cMenuSetupSoft(cSoftHdDevice *device)
 	// Video
 	//
 	BuildDisplayModeList();
+	BuildFastChannelSwitchModeList();
 
 	m_cVideoMenu = 0;
 	m_cVideoEnableHDR          = m_pConfig->ConfigVideoEnableHDR;
@@ -437,6 +439,18 @@ void cMenuSetupSoft::BuildDisplayModeList(void)
 		m_displayModePtrs.push_back(s.c_str());
 }
 
+void cMenuSetupSoft::BuildFastChannelSwitchModeList(void)
+{
+	m_fastChannelSwitchMode.clear();
+
+	m_fastChannelSwitchMode.push_back(trVDR("off"));
+	m_fastChannelSwitchMode.push_back(tr("video"));
+	m_fastChannelSwitchMode.push_back(tr("video and audio"));
+
+	for (auto &s : m_fastChannelSwitchMode)
+		m_fastChannelSwitchModePtrs.push_back(s.c_str());
+}
+
 /**
  * Store settings
  */

softhdsetupmenu.h

@@ -118,10 +118,13 @@ class cMenuSetupSoft : public cMenuSetupPage {
 
 	std::vector<std::string> m_displayMode;
 	std::vector<const char *> m_displayModePtrs;
+	std::vector<std::string> m_fastChannelSwitchMode;
+	std::vector<const char *> m_fastChannelSwitchModePtrs;
 
 	inline cOsdItem * CollapsedItem(const char *, int &, const char * = NULL);
 	void Create(void);
 	void BuildDisplayModeList(void);
+	void BuildFastChannelSwitchModeList(void);
 
 protected:
 	virtual void Store(void);

videorender.cpp

@@ -786,7 +786,7 @@ bool cVideoRender::DisplayFrame(void)
 			} else {
 				if (m_pConfig->ConfigShowChannelSwitchDurationMessage)
 					Skins.Message(mtInfo, cString::sprintf(tr("channel switch done in %ldms (%ldms)"), channelSwitchDurationMs, durationSinceFirstPacketMs));
-				LOGDEBUG("in sync after channel switch in %dms, %dms after first packet was received", channelSwitchDurationMs, durationSinceFirstPacketMs);
+				LOGDEBUG("playback start fired %dms after channel switch, %dms after first packet was received", channelSwitchDurationMs, durationSinceFirstPacketMs);
 			}
 		}