player: handle rebasing start time differently

Most of this is explained in the DOCS additions.

This gives us slightly more sanity, because there is less interaction
between the various parts. The goal is getting rid of the video_offset
entirely.

The simplification extends to the user API. In particular, we don't need
to fix missing parts in the API, such as the lack for a seek command
that seeks relatively to the start time. All these things are now
transparent.

(If someone really wants to know the real timestamps/start time, new
properties would have to be added.)

1 files changed, 10 insertions, 12 deletions

diff --git a/player/playloop.c b/player/playloop.c
index 643f290c48..6fa7b62292 100644
--- a/player/playloop.c
+++ b/player/playloop.c
@@ -205,7 +205,7 @@ static int mp_seek(MPContext *mpctx, struct seek_params seek,
     case MPSEEK_FACTOR: ;
         double len = get_time_length(mpctx);
         if (len >= 0)
-            target_time = seek.amount * len + get_start_time(mpctx);
+            target_time = seek.amount * len;
         break;
     }
 
@@ -405,15 +405,14 @@ double get_playback_time(struct MPContext *mpctx)
     double cur = get_current_time(mpctx);
     if (cur == MP_NOPTS_VALUE)
         return cur;
-    double start = get_start_time(mpctx);
     // During seeking, the time corresponds to the last seek time - apply some
     // cosmetics to it.
     if (mpctx->playback_pts == MP_NOPTS_VALUE) {
         double length = get_time_length(mpctx);
         if (length >= 0)
-            cur = MPCLAMP(cur, start, start + length);
+            cur = MPCLAMP(cur, 0, length);
     }
-    return cur >= start ? cur - start : cur;
+    return cur;
 }
 
 // Return playback position in 0.0-1.0 ratio, or -1 if unknown.
@@ -423,15 +422,15 @@ double get_current_pos_ratio(struct MPContext *mpctx, bool use_range)
     if (!demuxer)
         return -1;
     double ans = -1;
-    double start = get_start_time(mpctx);
+    double start = 0;
     double len = get_time_length(mpctx);
     if (use_range) {
         double startpos = rel_time_to_abs(mpctx, mpctx->opts->play_start);
         double endpos = get_play_end_pts(mpctx);
-        if (endpos == MP_NOPTS_VALUE || endpos > start + MPMAX(0, len))
-            endpos = start + MPMAX(0, len);
-        if (startpos == MP_NOPTS_VALUE || startpos < start)
-            startpos = start;
+        if (endpos == MP_NOPTS_VALUE || endpos > MPMAX(0, len))
+            endpos = MPMAX(0, len);
+        if (startpos == MP_NOPTS_VALUE || startpos < 0)
+            startpos = 0;
         if (endpos < startpos)
             endpos = startpos;
         start = startpos;
@@ -506,7 +505,7 @@ char *chapter_name(struct MPContext *mpctx, int chapter)
 double chapter_start_time(struct MPContext *mpctx, int chapter)
 {
     if (chapter == -1)
-        return get_start_time(mpctx);
+        return 0;
     if (chapter >= 0 && chapter < mpctx->num_chapters)
         return mpctx->chapters[chapter].pts;
     return MP_NOPTS_VALUE;
@@ -785,8 +784,7 @@ static void handle_loop_file(struct MPContext *mpctx)
     if (opts->loop_file && mpctx->stop_play == AT_END_OF_FILE) {
         mpctx->stop_play = KEEP_PLAYING;
         set_osd_function(mpctx, OSD_FFW);
-        queue_seek(mpctx, MPSEEK_ABSOLUTE, get_start_time(mpctx),
-                   MPSEEK_DEFAULT, true);
+        queue_seek(mpctx, MPSEEK_ABSOLUTE, 0, MPSEEK_DEFAULT, true);
         if (opts->loop_file > 0)
             opts->loop_file--;
     }