Matroska seeking fixes

If a relative seek forward went past the last index position the
Matroska demuxer did not seek to any index position. It did however set
the mkv_d->skip_to_timecode variable which meant that the next
fill_buffer() call would read from the current position until the target
position (probably the end of the file). Fix this by changing the code
to seek to the last index position if that is between the current and
target positions.

Also change backwards relative seek to accept an exactly matching index
position (<= vs <) and reorganize the seeking conditionals to allow
making the above change without turning the code into a complete mess.


git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@22634 b3059339-0415-0410-9bf9-f77b7e298cf2

1 files changed, 22 insertions, 12 deletions

diff --git a/libmpdemux/demux_mkv.c b/libmpdemux/demux_mkv.c
index 28e9cc8ded..3bdedb4eb6 100644
--- a/libmpdemux/demux_mkv.c
+++ b/libmpdemux/demux_mkv.c
@@ -28,6 +28,8 @@
 #include "libass/ass.h"
 #include "libass/ass_mp.h"
 
+#include "libavutil/common.h"
+
 #ifdef USE_QTX_CODECS
 #include "loader/qtx/qtxsdk/components.h"
 #endif
@@ -3554,18 +3556,26 @@ demux_mkv_seek (demuxer_t *demuxer, float rel_seek_secs, float audio_delay, int
                 diff = target_timecode + mkv_d->first_tc -
                        (int64_t) mkv_d->indexes[i].timecode * mkv_d->tc_scale / 1000000.0;
 
-                if ((flags & 1 || target_timecode <= mkv_d->last_pts*1000)
-                    && diff >= 0 && diff < min_diff)
-                  {
-                    min_diff = diff;
-                    index = mkv_d->indexes + i;
-                  }
-                else if (target_timecode > mkv_d->last_pts*1000
-                         && diff < 0 && -diff < min_diff)
-                  {
-                    min_diff = -diff;
-                    index = mkv_d->indexes + i;
-                  }
+                if ((flags & 1 || target_timecode <= mkv_d->last_pts*1000)) {
+                    // Absolute seek or seek backward: find the last index
+                    // position before target time
+                    if (diff < 0 || diff >= min_diff)
+                        continue;
+                }
+                else {
+                    // Relative seek forward: find the first index position
+                    // after target time. If no such index exists, find last
+                    // position between current position and target time.
+                    if (diff <= 0) {
+                        if (min_diff <= 0 && diff <= min_diff)
+                            continue;
+                    }
+                    else if (diff >= FFMIN(target_timecode - mkv_d->last_pts,
+                                           min_diff))
+                        continue;
+                }
+                min_diff = diff;
+                index = mkv_d->indexes + i;
               }
 
           if (index)  /* We've found an entry. */