From e0f4a99b99532d195ad40a161b633d39bcba4725 Mon Sep 17 00:00:00 2001
From: Johns <johns98@gmx.net>
Date: Wed, 22 Apr 2015 12:14:15 +0200
Subject: [PATCH] Workaround for ffmpeg 2.6 artifacts.

---
 ChangeLog   |  1 +
 codec.c     | 35 ++++++++++++++++++++++++++++++++++-
 codec.h     |  9 ++++++++-
 softhddev.c |  5 ++++-
 4 files changed, 47 insertions(+), 3 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 679636b..a949dd8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,6 +1,7 @@
 User johns
 Date:
 
+    Workaround for ffmpeg 2.6 artifacts.
     Fix bug: brightness and .. are calculated wrong.
     Add automatic frame rate detection for older ffmpeg versions.
     Fix bug: destroyed vdpau surfaces still used in queue.
diff --git a/codec.c b/codec.c
index 10011c3..cbf6f39 100644
--- a/codec.c
+++ b/codec.c
@@ -1,7 +1,7 @@
 ///
 ///	@file codec.c	@brief Codec functions
 ///
-///	Copyright (c) 2009 - 2014 by Johns.  All Rights Reserved.
+///	Copyright (c) 2009 - 2015 by Johns.  All Rights Reserved.
 ///
 ///	Contributor(s):
 ///
@@ -93,6 +93,16 @@
 #include "audio.h"
 #include "codec.h"
 
+//----------------------------------------------------------------------------
+
+    // correct is AV_VERSION_INT(56,35,101) but some gentoo i* think
+    // they must change it.
+#if LIBAVCODEC_VERSION_INT >= AV_VERSION_INT(56,26,100)
+    /// ffmpeg 2.6 started to show artifacts after channel switch
+    /// to SDTV channels
+#define FFMPEG_WORKAROUND_ARTIFACTS	1
+#endif
+
 //----------------------------------------------------------------------------
 //	Global
 //----------------------------------------------------------------------------
@@ -105,6 +115,9 @@
       ///
 static pthread_mutex_t CodecLockMutex;
 
+    /// Flag prefer fast xhannel switch
+char CodecUsePossibleDefectFrames;
+
 //----------------------------------------------------------------------------
 //	Video
 //----------------------------------------------------------------------------
@@ -126,6 +139,9 @@ struct _video_decoder_
     int GetFormatDone;			///< flag get format called!
     AVCodec *VideoCodec;		///< video codec
     AVCodecContext *VideoCtx;		///< video codec context
+#ifdef FFMPEG_WORKAROUND_ARTIFACTS
+    int FirstKeyFrame;			///< flag first frame
+#endif
     AVFrame *Frame;			///< decoded video frame
 };
 
@@ -525,6 +541,9 @@ void CodecVideoOpen(VideoDecoder * decoder, const char *name, int codec_id)
     }
     // reset buggy ffmpeg/libav flag
     decoder->GetFormatDone = 0;
+#ifdef FFMPEG_WORKAROUND_ARTIFACTS
+    decoder->FirstKeyFrame = 1;
+#endif
 }
 
 /**
@@ -611,8 +630,22 @@ void CodecVideoDecode(VideoDecoder * decoder, const AVPacket * avpkt)
     }
 
     if (got_frame) {			// frame completed
+#ifdef FFMPEG_WORKAROUND_ARTIFACTS
+	if (!CodecUsePossibleDefectFrames && decoder->FirstKeyFrame) {
+	    decoder->FirstKeyFrame++;
+	    if (frame->key_frame) {
+		Debug((3, "codec: key frame after %d frames\n",
+			decoder->FirstKeyFrame);
+		    decoder->FirstKeyFrame = 0;
+		}
+	    } else {
+		//DisplayPts(video_ctx, frame);
+		VideoRenderFrame(decoder->HwDecoder, video_ctx, frame);
+	    }
+#else
 	//DisplayPts(video_ctx, frame);
 	VideoRenderFrame(decoder->HwDecoder, video_ctx, frame);
+#endif
     } else {
 	// some frames are needed for references, interlaced frames ...
 	// could happen with h264 dvb streams, just drop data.
diff --git a/codec.h b/codec.h
index 995573a..eccaf00 100644
--- a/codec.h
+++ b/codec.h
@@ -1,7 +1,7 @@
 ///
 ///	@file codec.h	@brief Codec module headerfile
 ///
-///	Copyright (c) 2009 - 2013 by Johns.  All Rights Reserved.
+///	Copyright (c) 2009 - 2013, 2015 by Johns.  All Rights Reserved.
 ///
 ///	Contributor(s):
 ///
@@ -43,6 +43,13 @@ typedef struct _video_decoder_ VideoDecoder;
     /// Audio decoder typedef.
 typedef struct _audio_decoder_ AudioDecoder;
 
+//----------------------------------------------------------------------------
+//	Variables
+//----------------------------------------------------------------------------
+
+    /// Flag prefer fast xhannel switch
+extern char CodecUsePossibleDefectFrames;
+
 //----------------------------------------------------------------------------
 //	Prototypes
 //----------------------------------------------------------------------------
diff --git a/softhddev.c b/softhddev.c
index 5afe3b5..a44f020 100644
--- a/softhddev.c
+++ b/softhddev.c
@@ -1,7 +1,7 @@
 ///
 ///	@file softhddev.c	@brief A software HD device plugin for VDR.
 ///
-///	Copyright (c) 2011 - 2014 by Johns.  All Rights Reserved.
+///	Copyright (c) 2011 - 2015 by Johns.  All Rights Reserved.
 ///
 ///	Contributor(s):
 ///
@@ -2905,6 +2905,7 @@ const char *CommandLineHelp(void)
 	"\talsa-no-close-open\tdisable close open to fix alsa no sound bug\n"
 	"\talsa-close-open-delay\tenable close open delay to fix no sound bug\n"
 	"\tignore-repeat-pict\tdisable repeat pict message\n"
+	"\tuse-possible-defect-frames prefer faster channel switch\n"
 	"  -D\t\tstart in detached mode\n";
 }
 
@@ -2986,6 +2987,8 @@ int ProcessArgs(int argc, char *const argv[])
 		    AudioAlsaCloseOpenDelay = 1;
 		} else if (!strcasecmp("ignore-repeat-pict", optarg)) {
 		    VideoIgnoreRepeatPict = 1;
+		} else if (!strcasecmp("use-possible-defect-frames", optarg)) {
+		    CodecUsePossibleDefectFrames = 1;
 		} else {
 		    fprintf(stderr, _("Workaround '%s' unsupported\n"),
 			optarg);