diff options
| -rw-r--r-- | CONTRIBUTORS | 1 | ||||
| -rw-r--r-- | HISTORY | 2 | ||||
| -rw-r--r-- | dvbapi.c | 68 |
3 files changed, 65 insertions, 6 deletions
diff --git a/CONTRIBUTORS b/CONTRIBUTORS index 4d5dee50..f3d96430 100644 --- a/CONTRIBUTORS +++ b/CONTRIBUTORS @@ -101,6 +101,7 @@ Stefan Huelswitt <huels@iname.com> for making the width and height of the OSD configurable for implementing the "Jump" function in replay mode for implementing "Multi Speed Mode" + for implementing backtracing for fast forward/rewind Ulrich Röder <dynamite@efr-net.de> for pointing out that there are channels that have a symbol rate higher than @@ -735,3 +735,5 @@ Video Disk Recorder Revision History - Switching through channel groups with the "Left" and "Right" keys now always starts at the group that contains the current channel. - Implemented "Multi Speed Mode" (thanks to Stefan Huelswitt). +- Implemented backtracing to hit the right spot after fast forward/rewind + (thanks to Stefan Huelswitt). @@ -7,7 +7,7 @@ * DVD support initially written by Andreas Schultz <aschultz@warp10.net> * based on dvdplayer-0.5 by Matjaz Thaler <matjaz.thaler@guest.arnes.si> * - * $Id: dvbapi.c 1.113 2001/09/09 12:52:41 kls Exp $ + * $Id: dvbapi.c 1.114 2001/09/09 13:34:41 kls Exp $ */ //#define DVDDEBUG 1 @@ -628,11 +628,68 @@ int ReadFrame(int f, uchar *b, int Length, int Max) return r; } +// --- cBackTrace ---------------------------------------------------------- + +#define AVG_FRAME_SIZE 15000 // an assumption about the average frame size +#define DVB_BUF_SIZE (256 * 1024) // an assumption about the dvb firmware buffer size +#define BACKTRACE_ENTRIES (DVB_BUF_SIZE / AVG_FRAME_SIZE + 20) // how many entries are needed to backtrace buffer contents + +class cBackTrace { +private: + int index[BACKTRACE_ENTRIES]; + int length[BACKTRACE_ENTRIES]; + int pos, num; +public: + cBackTrace(void); + void Clear(void); + void Add(int Index, int Length); + int Get(bool Forward); + }; + +cBackTrace::cBackTrace(void) +{ + Clear(); +} + +void cBackTrace::Clear(void) +{ + pos = num = 0; +} + +void cBackTrace::Add(int Index, int Length) +{ + index[pos] = Index; + length[pos] = Length; + if (++pos >= BACKTRACE_ENTRIES) + pos = 0; + if (num < BACKTRACE_ENTRIES) + num++; +} + +int cBackTrace::Get(bool Forward) +{ + int p = pos; + int n = num; + int l = DVB_BUF_SIZE + (Forward ? 0 : 256 * 1024); //XXX (256 * 1024) == DVB_BUF_SIZE ??? + int i = -1; + + while (n && l > 0) { + if (--p < 0) + p = BACKTRACE_ENTRIES - 1; + i = index[p] - 1; + l -= length[p]; + n--; + } + return i; +} + // --- cPlayBuffer --------------------------------------------------------- #define MAX_VIDEO_SLOWMOTION 63 // max. arg to pass to VIDEO_SLOWMOTION // TODO is this value correct? class cPlayBuffer : public cRingBufferFrame { +private: + cBackTrace backTrace; protected: enum ePlayModes { pmPlay, pmPause, pmSlow, pmFast, pmStill }; enum ePlayDirs { pdForward, pdBackward }; @@ -729,6 +786,7 @@ void cPlayBuffer::Output(void) } } writeIndex = frame->Index(); + backTrace.Add(frame->Index(), frame->Count()); Drop(frame); } } @@ -766,13 +824,15 @@ void cPlayBuffer::Empty(bool Block) while ((blockInput > 1 || blockOutput > 1) && time(NULL) - t0 < 2) usleep(1); Lock(); - readIndex = writeIndex; + if ((readIndex = backTrace.Get(playDir == pdForward)) < 0) + readIndex = writeIndex; cRingBufferFrame::Clear(); CHECK(ioctl(videoDev, VIDEO_CLEAR_BUFFER)); CHECK(ioctl(audioDev, AUDIO_CLEAR_BUFFER)); } if (!Block) { blockInput = blockOutput = 0; + backTrace.Clear(); Unlock(); } } @@ -830,10 +890,6 @@ void cPlayBuffer::Forward(void) TrickSpeed(Setup.MultiSpeedMode ? -1 : -MAX_SPEEDS); break; case pmFast: - //XXX - if (playDir == pdForward) - readIndex -= 150; // this about compensates for the buffered data, so that we don't get too far ahead - //XXX if (Setup.MultiSpeedMode) TrickSpeed(playDir == pdForward ? 1 : -1); else if (playDir == pdForward) |