libtriple: implement fast forward in cPlayback()

First try at implementing fast forward. Needs more love.
Reverse does not work yet, setting speed to negative values
right now simply resets to "play" mode.

libtriple/playback_td.cpp

@@ -329,15 +329,30 @@ bool cPlayback::SetAPid(unsigned short pid, bool _ac3)
 bool cPlayback::SetSpeed(int speed)
 {
 	INFO("speed = %d\n", speed);
-	if (speed != 0 && playback_speed == 0)
+	if (speed < 0)
+		speed = 1; /* fast rewind not yet implemented... */
+	if (speed == 1 && playback_speed != 1)
+	{
+		if (playback_speed == 0)
 		{
 			videoDemux->Stop();
 			videoDemux->Start();
 			audioDemux->Start();
+		}
+		else
+		{
+			audioDecoder->Stop();
+			videoDecoder->Stop();
+		}
 		audioDecoder->Start();
 		videoDecoder->Start();
 		playstate = STATE_PLAY;
 	}
+	if (playback_speed == 1 && speed > 1)
+	{
+		audioDecoder->mute(false);
+		videoDecoder->FastForwardMode();
+	}
 	playback_speed = speed;
 	if (playback_speed == 0)
 	{
@@ -698,9 +713,97 @@ ssize_t cPlayback::read_ts()
 	ssize_t toread, ret = 0, sync, off;
 	toread = INBUF_SIZE - inbuf_pos;
 	bool retry = true;
+	uint8_t *buf;
 	/* fprintf(stderr, "%s:%d curr_pos %lld, inbuf_pos: %ld, toread: %ld\n",
 		__FUNCTION__, __LINE__, (long long)curr_pos, (long)inbuf_pos, (long)toread); */
 
+	if (playback_speed > 1)
+	{
+		sync = 0;
+		ssize_t tmpread = PESBUF_SIZE / 188 * 188;
+		int n, skipped = 0;
+		bool skip = false;
+		bool eof = true;
+		while (toread > 0)
+		{
+			ssize_t done = 0;
+			while (done < tmpread)
+			{
+				ret = read(in_fd, pesbuf, tmpread - done);
+				if (ret == 0 && retry) /* EOF */
+				{
+					mf_lseek(curr_pos);
+					retry = false;
+					continue;
+				}
+				if (ret < 0)
+				{
+					INFO("failed: %m\n");
+					return ret;
+				}
+				if (ret == 0 && eof)
+					goto out;
+				eof = false;
+				done += ret;
+				curr_pos += ret;
+			}
+			sync = sync_ts(pesbuf, ret);
+			if (sync != 0)
+			{
+				INFO("out of sync: %d\n", sync);
+				if (sync < 0)
+				{
+					return -1;
+				}
+				memmove(pesbuf, pesbuf + sync, ret - sync);
+				if (pesbuf[0] != 0x47)
+					INFO("??????????????????????????????\n");
+			}
+			for (n = 0; n < done / 188 * 188; n += 188)
+			{
+				buf = pesbuf + n;
+				if (buf[1] & 0x40) // PUSI
+				{
+					/* only video packets... */
+					int of = 4;
+					if (buf[3] & 0x20) // adaptation field
+						of += buf[4] + 1;
+					if ((buf[of + 3] & 0xF0) == 0xE0 && // Video stream
+					    buf[of + 2] == 0x01 && buf[of + 1] == 0x00 && buf[of] == 0x00) // PES
+					{
+						skip = true;
+						skipped++;
+						if (skipped >= playback_speed)
+						{
+							skipped = 0;
+							skip = false;
+						}
+					}
+				}
+				if (! skip)
+				{
+					memcpy(inbuf + inbuf_pos, buf, 188);
+					inbuf_pos += 188;
+					toread -= 188;
+					if (toread <= 0)
+					{
+						/* the output buffer is full, discard the input :-( */
+						if (done - n > 0)
+						{
+							DBG("not done: %d, resetting filepos\n", done - n);
+							mf_lseek(curr_pos - (done - n));
+						}
+						break;
+					}
+				}
+			}
+		}
+ out:
+		if (eof)
+			return 0;
+	}
+	else
+	{
 		while(true)
 		{
 			ret = read(in_fd, inbuf + inbuf_pos, toread);
@@ -729,15 +832,16 @@ ssize_t cPlayback::read_ts()
 			return ret;
 		}
 		inbuf_sync += sync;
+	}
 	/* check for A/V PIDs */
 	uint16_t pid;
 	int i, j;
 	bool pid_new;
 	int64_t pts;
-	// fprintf(stderr, "inbuf_pos: %ld - sync: %ld\n", (long)inbuf_pos, (long)sync);
+	//fprintf(stderr, "inbuf_pos: %ld - sync: %ld, inbuf_syc: %ld\n", (long)inbuf_pos, (long)sync, (long)inbuf_sync);
 	int synccnt = 0;
 	for (i = 0; i < inbuf_pos - inbuf_sync - 13;) {
-		uint8_t *buf = inbuf + inbuf_sync + i;
+		buf = inbuf + inbuf_sync + i;
 		if (*buf != 0x47)
 		{
 			synccnt++;

libtriple/video_td.cpp

@@ -644,3 +644,9 @@ void cVideo::routeVideo(int standby)
 		perror("IOC_AVS_ROUTE_ENC2TV");
 	close(avsfd);
 }
+
+void cVideo::FastForwardMode(int mode)
+{
+	lt_debug("cVideo::%s\n", __FUNCTION__);
+	fop(ioctl, MPEG_VID_FASTFORWARD, mode);
+}

libtriple/video_td.h

@@ -179,6 +179,7 @@ class cVideo
 		void SetVideoMode(analog_mode_t mode);
 		void SetDBDR(int) { return; };
 		void SetAudioHandle(void *) { return; };
+		void FastForwardMode(int mode = 0);
 		void SetAutoModes(int [VIDEO_STD_MAX]) { return; };
 		int  OpenVBI(int) { return 0; };
 		int  CloseVBI(void) { return 0; };