From 89fa20bb75e453f0616ee2fa8425afe14773a34c Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Sun, 18 Nov 2012 09:53:13 +0000
Subject: [PATCH] fix LTC frame TVstandard offset

<pre>
       Ardour-
      transport
     01:00:00:01
          |
          |
    5   5 |           NTSC Line
    2   2 |                                     1
    4   5 v 1   2   3   4   5   6   7   8   9   0
  ____________________             ________________    TV
  |   |   | | | | | | |_|_|_|_|_|_| | | | | | |   |

                          ^
                          |
                          v

    +-+ +-+ + + +-+   +-+ +---+   +---+
  | | | | | | | | |   | | |   |   |   |   |            LTC
  +-+ +-+ +-+ +-+ +---+ +-+   +---+   +---+

           SYNC-WORD      |
              LTC       B | B       LTC
          01:00:00:00   I | I   01:00:00:01
                        T   T
                        7
                        9   0
</pre>

git-svn-id: svn://localhost/ardour2/branches/3.0@13524 d708f5d6-7413-0410-9779-e7cbd77b26cf
---
 libs/ardour/ltc_slave.cc   | 8 ++++----
 libs/ardour/session_ltc.cc | 2 +-
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/libs/ardour/ltc_slave.cc b/libs/ardour/ltc_slave.cc
index 5d3ee83139..f063e830c1 100644
--- a/libs/ardour/ltc_slave.cc
+++ b/libs/ardour/ltc_slave.cc
@@ -359,13 +359,13 @@ LTC_Slave::process_ltc(framepos_t const now)
 			ltc_frame_increment(&frame.ltc, fps_i, tv_standard, 0);
 			ltc_frame_to_time(&stime, &frame.ltc, 0);
 			transport_direction = 1;
-			frame.off_start += ltc_frame_alignment(session.frames_per_timecode_frame(), tv_standard);
-			frame.off_end += ltc_frame_alignment(session.frames_per_timecode_frame(), tv_standard);
+			frame.off_start -= ltc_frame_alignment(session.frames_per_timecode_frame(), tv_standard);
+			frame.off_end -= ltc_frame_alignment(session.frames_per_timecode_frame(), tv_standard);
 		} else {
 			ltc_frame_decrement(&frame.ltc, fps_i, tv_standard, 0);
 			int off = frame.off_end - frame.off_start;
-			frame.off_start += off + ltc_frame_alignment(session.frames_per_timecode_frame(), tv_standard);
-			frame.off_end += off + ltc_frame_alignment(session.frames_per_timecode_frame(), tv_standard);
+			frame.off_start += off - ltc_frame_alignment(session.frames_per_timecode_frame(), tv_standard);
+			frame.off_end += off - ltc_frame_alignment(session.frames_per_timecode_frame(), tv_standard);
 			transport_direction = -1;
 		}
 
diff --git a/libs/ardour/session_ltc.cc b/libs/ardour/session_ltc.cc
index d30e157a1b..177598091e 100644
--- a/libs/ardour/session_ltc.cc
+++ b/libs/ardour/session_ltc.cc
@@ -246,7 +246,7 @@ Session::ltc_tx_send_time_code_for_cycle (framepos_t start_frame, framepos_t end
 	framepos_t cycle_start_frame = (current_speed < 0) ? (start_frame - ltc_out_latency.max) : (start_frame + ltc_out_latency.max);
 
 	/* LTC TV standard offset */
-	cycle_start_frame += ltc_frame_alignment(frames_per_timecode_frame(), TV_STANDARD(cur_timecode));
+	cycle_start_frame -= ltc_frame_alignment(frames_per_timecode_frame(), TV_STANDARD(cur_timecode));
 
 	/* cycle-start may become negative due to latency compensation */
 	if (cycle_start_frame < 0) { cycle_start_frame = 0; }