cubicibo/MR/timegrid: Rewrite time handling to sample on frame grid

The time unit is now the frame count and FPS rather than the integer ms frame duration.

Author: cubicibo

ass2bdnxml.c

@@ -23,19 +23,13 @@
 
 #include "common.h"
 
-typedef struct frate_s {
-    char *name;
-    int rate;
-    double frame_dur;
-} frate_t;
-
 frate_t frates[] = {
-    {"23.976", 24, 1000.0 / (24000.0 / 1001.0)},
-    {"24", 24, 1000.0 / (24.0 / 1.0)},
-    {"25", 25, 1000.0 / (25.0 / 1.0)},
-    {"29.97", 30, 1000.0 / (30000.0 / 1001.0)},
-    {"50", 50, 1000.0 / (50.0 / 1.0)},
-    {"59.94", 60, 1000.0 / (60000.0 / 1001.0)},
+    {"23.976",24, 1000.0 / (24000.0 / 1001.0), 24000, 1001},
+    {"24", 24, 1000.0 / (24.0 / 1.0), 24, 1},
+    {"25", 25, 1000.0 / (25.0 / 1.0), 25, 1},
+    {"29.97", 30, 1000.0 / (30000.0 / 1001.0), 30000, 1001},
+    {"50", 50, 1000.0 / (50.0 / 1.0), 50, 1},
+    {"59.94", 60, 1000.0 / (60000.0 / 1001.0), 60000, 1001},
     {NULL, 0, 0}
 };
 
@@ -88,6 +82,24 @@ void mktc(int tc, int fps, char *buf)
     }
 }
 
+static void frame_to_tc(uint64_t frames, frate_t *fps, char *buf)
+{
+    frames--;
+    uint8_t  frame = frames % fps->rate;
+    uint64_t ts = frames/fps->rate;
+    uint8_t  sec = ts % 60;
+    ts /= 60;
+    uint8_t m = ts % 60;
+    ts /= 60;
+    if (ts > 99) {
+        fprintf(stderr, "timestamp overflow (more than 99 hours).\n");
+        exit(1);
+    } else if (snprintf(buf, 12, "%02d:%02d:%02d:%02d", (uint8_t)ts, m, sec, frame) != 11) {
+        fprintf(stderr, "Timecode lead to invalid format: %s\n", buf);
+        exit(1);
+    }
+}
+
 void write_xml(eventlist_t *evlist, vfmt_t *vfmt, frate_t *frate,
                char *track_name, char *language, opts_t *args)
 {
@@ -103,9 +115,10 @@ void write_xml(eventlist_t *evlist, vfmt_t *vfmt, frate_t *frate,
         exit(1);
     }
 
-    mktc(evlist->events[0]->in / frate->frame_dur, frate->rate, buf_in);
-    mktc(evlist->events[evlist->nmemb - 1]->out / frate->frame_dur,
-         frate->rate, buf_out);
+    //mktc(evlist->events[0]->in / frate->frame_dur, frate->rate, buf_in);
+    //mktc(evlist->events[evlist->nmemb - 1]->out / frate->frame_dur, frate->rate, buf_out);
+    frame_to_tc(evlist->events[0]->in, frate, buf_in);
+    frame_to_tc(evlist->events[evlist->nmemb - 1]->out, frate, buf_out);
 
     fprintf(of, "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"
                 "<BDN Version=\"0.93\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xsi:noNamespaceSchemaLocation=\"BD-03-006-0093b BDN File Format.xsd\">\n"
@@ -116,15 +129,19 @@ void write_xml(eventlist_t *evlist, vfmt_t *vfmt, frate_t *frate,
                 "    <Events LastEventOutTC=\"%s\" FirstEventInTC=\"%s\" ",
             track_name, language, vfmt->name, frate->name, buf_out, buf_in);
 
-    mktc(0, frate->rate, buf_in);
+    //mktc(0, frate->rate, buf_in);
+    frame_to_tc(1, frate, buf_in);
+
     fprintf(of, "ContentInTC=\"%s\" ContentOutTC=\"%s\" NumberofEvents=\"%d\" Type=\"Graphic\"/>\n"
                 "  </Description>\n"
                 "  <Events>\n", buf_in, buf_out, evlist->nmemb);
 
     for (i = 0; i < evlist->nmemb; i++) {
         image_t *img = evlist->events[i];
-        mktc(img->in / frate->frame_dur, frate->rate, buf_in);
-        mktc(img->out / frate->frame_dur, frate->rate, buf_out);
+        frame_to_tc(img->in, frate, buf_in);
+        frame_to_tc(img->out, frate, buf_out);
+        //mktc(img->in / frate->frame_dur, frate->rate, buf_in);
+        //mktc(img->out / frate->frame_dur, frate->rate, buf_out);
 
         fprintf(of, "    <Event Forced=\"False\" InTC=\"%s\" OutTC=\"%s\">\n",
                 buf_in, buf_out);
@@ -313,9 +330,7 @@ int main(int argc, char *argv[])
         }
     }
 
-    args.fps = frate->rate;
-
-    evlist = render_subs(subfile, rint(frate->frame_dur), &args);
+    evlist = render_subs(subfile, frate, &args);
 
     write_xml(evlist, vfmt, frate, track_name, language, &args);
 

common.h

@@ -1,14 +1,24 @@
+#include <stdint.h>
+
 typedef struct BoundingBox_s {
     int x1;
     int x2;
     int y1;
     int y2;
 } BoundingBox_t;
 
+typedef struct frate_s {
+    char *name;
+    int rate;
+    double frame_dur;
+    uint64_t num;
+    uint64_t denom;
+} frate_t;
+
 typedef struct image_s {
     int width, height, stride, dvd_mode;
     int subx1, suby1, subx2, suby2;
-    long long in, out;
+    uint64_t in, out;
     BoundingBox_t crops[2];
     uint8_t *buffer;
 } image_t;
@@ -20,7 +30,6 @@ typedef struct eventlist_s {
 
 typedef struct opts_s {
     double par;
-    int fps;
     int frame_w;
     int frame_h;
     int render_w;
@@ -33,4 +42,4 @@ typedef struct opts_s {
     const char *fontdir;
 } opts_t;
 
-eventlist_t *render_subs(char *subfile, int frame_d, opts_t *args);
+eventlist_t *render_subs(char *subfile, frate_t *frate, opts_t *args);

render.c

@@ -10,6 +10,13 @@
 #define MIN(a,b) ((a) > (b) ? (b) : (a))
 #define BOX_AREA(box) ((box.x2-box.x1)*(box.y2-box.y1))
 
+typedef enum SamplingFlag_s {
+    SAMPLE_TC_IN  = 0,
+    SAMPLE_TC_OUT,
+    SAMPLE_TC_MID,
+    INVALID_SAMPLING
+} SamplingFlag_t;
+
 ASS_Library *ass_library;
 ASS_Renderer *ass_renderer;
 
@@ -357,35 +364,52 @@ static int find_split(image_t *frame)
     return best_score < (uint32_t)(-1);
 }
 
-static int get_frame(ASS_Renderer *renderer, ASS_Track *track, image_t *frame,
-                     long long time, int frame_d)
+static uint64_t frame_to_realtime_ms(uint64_t frame_cnt, frate_t *frate, SamplingFlag_t flag)
+{
+    if (flag == SAMPLE_TC_OUT) {
+        return (uint64_t)floor((1000 * frame_cnt * frate->denom)/(double)frate->num);
+    } else if (flag == SAMPLE_TC_IN) {
+        return (uint64_t)ceil((1000*(frame_cnt - 1) * frate->denom)/(double)frate->num);
+    } else if (flag == SAMPLE_TC_MID) {
+        return (uint64_t)round(((1000*frame_cnt * frate->denom)/frate->num) - (500*frate->denom)/frate->num);
+    }
+    fprintf(stderr, "Invalid sampling flag.\n");
+    exit(1);
+}
+
+static int get_frame(ASS_Renderer *renderer, ASS_Track *track,
+                     image_t *frame, uint64_t frame_cnt, frate_t *frate)
 {
     int changed;
-    ASS_Image *img = ass_render_frame(renderer, track, time, &changed);
+
+    uint64_t ms = frame_to_realtime_ms(frame_cnt, frate, SAMPLE_TC_MID);
+    ASS_Image *img = ass_render_frame(renderer, track, ms, &changed);
 
     if (changed && img) {
-        frame->out = time + frame_d;
+        frame->out = frame_cnt + 1;
         blend(frame, img);
-        frame->in = time;
+        frame->in = frame_cnt;
 
         if (frame->subx1 == -1 || frame->suby1 == -1)
             return 2;
 
         return 3;
     } else if (!changed && img) {
-        frame->out = time + frame_d;
+        ++frame->out;
         return 1;
     } else {
         return 0;
     }
 }
 
-eventlist_t *render_subs(char *subfile, int frame_d, opts_t *args)
+eventlist_t *render_subs(char *subfile, frate_t *frate, opts_t *args)
 {
     long long tm = 0;
     int count = 0, fres = 0;
     int img_cnt;
 
+    uint64_t frame_cnt = 1;
+
     eventlist_t *evlist = calloc(1, sizeof(eventlist_t));
 
     init(args);
@@ -403,7 +427,7 @@ eventlist_t *render_subs(char *subfile, int frame_d, opts_t *args)
             eventlist_set(evlist, frame, count - 1);
         }
 
-        fres = get_frame(ass_renderer, track, frame, tm, frame_d);
+        fres = get_frame(ass_renderer, track, frame, frame_cnt, frate);
 
         switch (fres) {
             case 3:
@@ -429,16 +453,21 @@ eventlist_t *render_subs(char *subfile, int frame_d, opts_t *args)
             /* fall through */
             case 2:
             case 1:
-                tm += frame_d;
+                ++frame_cnt;
                 break;
             case 0:
             {
-                long long offset = ass_step_sub(track, tm, 1);
+                tm = (uint64_t)ass_step_sub(track, frame_to_realtime_ms(frame_cnt, frate, SAMPLE_TC_MID), 1);
+                uint64_t offset = (tm*frate->rate)/1000;
 
-                if (tm && !offset)
+                if (!tm && frame_cnt > 1)
                     goto finish;
 
-                tm += offset;
+                if (offset == 0) {
+                    offset = 1; //avoid deadlocks
+                }
+
+                frame_cnt += offset;
                 break;
             }
         }