device: enable fast channel switch

Author: rellla

README.md

@@ -203,6 +203,10 @@ Setup: /etc/vdr/setup.conf
 		2  = display mode follows video resolution respecting interlaced modes (width, height, refresh rate, interlaced flag)
 		     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
+
 	softhddevice-drm-gles.MaxSizeGPUImageCache = 128
 		how many GPU memory should be used for image caching
 

config.cpp

@@ -40,6 +40,7 @@ bool cSoftHdConfig::SetupParse(const char *name, const char *value)
 	// Video
 	} else if (!strcasecmp(name, "VideoEnableHDR"))        { ConfigVideoEnableHDR = atoi(value);
 	} else if (!strcasecmp(name, "VideoDisplayMode"))      { ConfigVideoDisplayMode = std::min(atoi(value), static_cast<int>(CONFIG_DISPLAY_MODE_FOLLOW_VIDEO_INTERLACED));
+	} else if (!strcasecmp(name, "VideoFastChannelSwitch")){ ConfigVideoFastChannelSwitch = atoi(value);
 
 	// Audio
 	} else if (!strcasecmp(name, "AudioSoftvol"))          { ConfigAudioSoftvol = atoi(value);

config.h

@@ -58,6 +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
 
 	// Audio
 	bool ConfigAudioSoftvol = false;            ///< config use software volume

softhddevice.cpp

@@ -94,6 +94,7 @@ bool cSoftHdDevice::Initialize(void)
 	m_dataReceivedTime = m_channelSwitchStartTime;
 
 	m_pipUseAlt = m_pConfig->ConfigPipUseAlt;
+	m_fastChannelSwitch = m_pConfig->ConfigVideoFastChannelSwitch;
 
 	m_initialized = true;
 
@@ -1633,7 +1634,11 @@ void cSoftHdDevice::EnterState(State state)
 	switch (state) {
 		case BUFFERING:
 			m_pAudio->ResetHwDelayBaseline();
-			// nothing
+			if (m_fastChannelSwitch) {
+				LOGDEBUG2(L_AV_SYNC, "%s: fast channel switch: display one frame and then pause", __FUNCTION__);
+				m_pRender->SetPlaybackPaused(false);
+				m_pRender->SetDisplayOneFrameThenPause(true);
+			}
 			break;
 		case PLAY:
 			if (m_playbackMode != VIDEO_ONLY)

softhddevice.h

@@ -147,6 +147,7 @@ class cSoftHdDevice : public cDevice, public cStatus {
 	void SetParseH264Dimensions(void);
 	void SetDecoderFallbackToSw(bool);
 	void SetEnableHdr(bool);
+	void SetEnableFastChannelSwitch(bool enable) { m_fastChannelSwitch = enable; };
 	void SetDisplayMode(int);
 	bool IsBufferingThresholdReached(void);
 	bool IsVideoOnlyPlayback(void) { return m_playbackMode == VIDEO_ONLY; };
@@ -256,6 +257,7 @@ 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
 
 	std::atomic<PlaybackMode> m_playbackMode = NONE; ///< current playback mode
 	int m_audioChannelID = -1;       ///< current audio channel ID

softhdsetupmenu.cpp

@@ -77,6 +77,7 @@ 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")));
 	}
 
 	//
@@ -304,6 +305,7 @@ cMenuSetupSoft::cMenuSetupSoft(cSoftHdDevice *device)
 	m_cVideoMenu = 0;
 	m_cVideoEnableHDR          = m_pConfig->ConfigVideoEnableHDR;
 	m_cVideoDisplayMode        = m_pConfig->ConfigVideoDisplayMode;
+	m_cVideoFastChannelSwitch  = m_pConfig->ConfigVideoFastChannelSwitch;
 
 	//
 	// Audio
@@ -455,6 +457,8 @@ void cMenuSetupSoft::Store(void)
 	// only save default and auto adjusted modes
 	if (m_pConfig->ConfigVideoDisplayMode < CONFIG_DISPLAY_MODE_MANUAL)
 		SetupStore("VideoDisplayMode", m_cVideoDisplayMode);
+	SetupStore("VideoFastChannelSwitch", m_pConfig->ConfigVideoFastChannelSwitch = m_cVideoFastChannelSwitch);
+	m_pDevice->SetEnableFastChannelSwitch(m_pConfig->ConfigVideoFastChannelSwitch);
 
 	//
 	// Audio

softhdsetupmenu.h

@@ -41,6 +41,7 @@ class cMenuSetupSoft : public cMenuSetupPage {
 	int m_cVideoMenu;
 	int m_cVideoEnableHDR;
 	int m_cVideoDisplayMode;
+	int m_cVideoFastChannelSwitch;
 
 	// Audio
 	int m_cAudioMenu;

videorender.cpp

@@ -720,6 +720,7 @@ bool cVideoRender::DisplayFrame(void)
 		m_eventQueue.push_back(BufferingThresholdReachedEvent{});
 
 	bool skipBufferUnderrunCheck = m_videoPlaybackPaused ||
+	                               m_displayOneFrameThenPause ||
 	                               m_videoPlaybackPauseScheduledAt != AV_NOPTS_VALUE ||
 	                               m_pDevice->IsVideoOnlyPlayback() ||
 	                               IsTrickSpeed() ||
@@ -772,19 +773,26 @@ bool cVideoRender::DisplayFrame(void)
 				m_pAudio->DropSamplesOlderThanPtsMs(drmBuffer->frame->pts * 1000 * av_q2d(m_timebase));
 		}
 
-		if (m_displayOneFrameThenPause) {
-			m_videoPlaybackPaused = true;
-			m_displayOneFrameThenPause = false;
-		}
-
 		pageFlipDone = PageFlip(drmBuffer, pipBuffer);
-		if (m_startCounter == 1 && m_pDevice->Transferring()) {
+
+		// log channel switch duration
+		if (m_pDevice->Transferring() && ((m_startCounter == 0 && m_displayOneFrameThenPause) || m_startCounter == 1)) {
 			auto now = std::chrono::steady_clock::now();
 			auto channelSwitchDurationMs = std::chrono::duration_cast<std::chrono::milliseconds>(now - m_pDevice->GetChannelSwitchStartTime()).count();
 			auto durationSinceFirstPacketMs = std::chrono::duration_cast<std::chrono::milliseconds>(now - m_pDevice->GetChannelSwitchFirstPacketTime()).count();
-			if (m_pConfig->ConfigShowChannelSwitchDurationMessage)
-				Skins.Message(mtInfo, cString::sprintf(tr("channel switch done in %ldms (%ldms)"), channelSwitchDurationMs, durationSinceFirstPacketMs));
-			LOGDEBUG("channel switch done in %dms, %dms after first packet was received", channelSwitchDurationMs, durationSinceFirstPacketMs);
+
+			if (m_startCounter == 0) {
+				LOGDEBUG("first frame displayed %dms after channel switch, %dms after first packet was received", channelSwitchDurationMs, durationSinceFirstPacketMs);
+			} 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);
+			}
+		}
+
+		if (m_displayOneFrameThenPause) {
+			m_videoPlaybackPaused = true;
+			m_displayOneFrameThenPause = false;
 		}
 
 		if (m_pCurrentlyDisplayed)