From c22482e08d4ca0514685e73b68479f0427b1f28f Mon Sep 17 00:00:00 2001
From: Rudolf Polzer <divverent@xonotic.org>
Date: Thu, 27 Sep 2012 11:08:59 +0200
Subject: TOOLS: fix first frame pts for dlopen/telecine.so

When the first frame of a telecine pattern did not generate an output
frame (because it is a 0 or a 1), this could lead to the first two
output frames getting equal pts values.

When the first frame of a telecine pattern generates exactly one output
frame (i.e. when the telecine pattern starts with 2 or 3), then the
output was correct before this comment, and still is unchanged.

When the first frame of a telecine pattern generates more than one
output frame (i.e. when it starts with 4 to 9), then output pts are
still broken. This is not really solvable without knowing the frame
duration, or delaying output by one frame.
---
 TOOLS/vf_dlopen/telecine.c | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

(limited to 'TOOLS')

diff --git a/TOOLS/vf_dlopen/telecine.c b/TOOLS/vf_dlopen/telecine.c
index 109fef2d6b..1b3db26a20 100644
--- a/TOOLS/vf_dlopen/telecine.c
+++ b/TOOLS/vf_dlopen/telecine.c
@@ -11,7 +11,7 @@
 /*
  * telecine filter
  *
- * usage: -vf dlopen=./telecine.so:t:32
+ * usage: -vf dlopen=./telecine.so:t:23
  *
  * Parameter: first parameter is "t" for top field first, "b" for bottom field first
  * then digits (0-9) for how many fields a frame is to be displayed
@@ -44,6 +44,7 @@ typedef struct {
     int occupied;
     double lastpts_in;
     double lastpts_out;
+    int first_frame_of_group;
 } tc_data_t;
 
 static int tc_config(struct vf_dlopen_context *ctx)
@@ -116,9 +117,9 @@ static int tc_put_image(struct vf_dlopen_context *ctx)
 
     if (tc->pattern_pos == 0 && !tc->occupied) {
         // at the start of the pattern, reset pts
-        double newpts = ctx->inpic.pts - (delta * tc->pts_num) / tc->pts_denom;
-        // printf("pts reset: %f -> %f (delta: %f)\n", tc->lastpts_out, newpts, newpts - tc->lastpts_out);
-        tc->lastpts_out = newpts;
+        // printf("pts reset: %f -> %f (delta: %f)\n", tc->lastpts_out, ctx->inpic.pts, ctx->inpic.pts - tc->lastpts_out);
+        tc->lastpts_out = ctx->inpic.pts;
+        tc->first_frame_of_group = 1;
     }
     ++tc->pattern_pos;
     if (!tc->pattern[tc->pattern_pos])
@@ -150,7 +151,10 @@ static int tc_put_image(struct vf_dlopen_context *ctx)
                 (ctx->inpic.planeheight[p] - !tc->firstfield + 1) / 2
                 );
         }
-        tc->lastpts_out += (delta * tc->pts_num) / tc->pts_denom;
+        if (tc->first_frame_of_group)
+            tc->first_frame_of_group = 0;
+        else
+            tc->lastpts_out += (delta * tc->pts_num) / tc->pts_denom;
         ctx->outpic[nout].pts = tc->lastpts_out;
         // printf("pts written: %f\n", ctx->outpic[nout].pts);
         ++nout;
@@ -167,7 +171,10 @@ static int tc_put_image(struct vf_dlopen_context *ctx)
                 MIN(ctx->inpic.planestride[p], ctx->outpic[nout].planestride[p]),
                 ctx->inpic.planeheight[p]
                 );
-        tc->lastpts_out += (delta * tc->pts_num) / tc->pts_denom;
+        if (tc->first_frame_of_group)
+            tc->first_frame_of_group = 0;
+        else
+            tc->lastpts_out += (delta * tc->pts_num) / tc->pts_denom;
         ctx->outpic[nout].pts = tc->lastpts_out;
         // printf("pts written: %f\n", ctx->outpic[nout].pts);
         ++nout;
-- 
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