[FFmpeg-cvslog] ffmpeg_opt: Compensate for DTS/ PTS difference in seeking when its based on DTS

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Mon May 18 20:27:04 2015 +0200| [b0322e4a9e326f41e0214abb0083fe9eb7407460] | committer: Michael Niedermayer

ffmpeg_opt: Compensate for DTS/PTS difference in seeking when its based on DTS

Fixes Ticket4554

Signed-off-by: Michael Niedermayer <michaelni at gmx.at>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=b0322e4a9e326f41e0214abb0083fe9eb7407460
---

 ffmpeg_opt.c |   15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/ffmpeg_opt.c b/ffmpeg_opt.c
index 5731299..a8d433e 100644
--- a/ffmpeg_opt.c
+++ b/ffmpeg_opt.c
@@ -927,7 +927,20 @@ static int open_input_file(OptionsContext *o, const char *filename)
 
     /* if seeking requested, we execute it */
     if (o->start_time != AV_NOPTS_VALUE) {
-        ret = avformat_seek_file(ic, -1, INT64_MIN, timestamp, timestamp, 0);
+        int64_t seek_timestamp = timestamp;
+
+        if (!(ic->iformat->flags & AVFMT_SEEK_TO_PTS)) {
+            int dts_heuristic = 0;
+            for (i=0; i<ic->nb_streams; i++) {
+                AVCodecContext *avctx = ic->streams[i]->codec;
+                if (avctx->has_b_frames)
+                    dts_heuristic = 1;
+            }
+            if (dts_heuristic) {
+                seek_timestamp -= 3*AV_TIME_BASE / 23;
+            }
+        }
+        ret = avformat_seek_file(ic, -1, INT64_MIN, seek_timestamp, seek_timestamp, 0);
         if (ret < 0) {
             av_log(NULL, AV_LOG_WARNING, "%s: could not seek to position %0.3f\n",
                    filename, (double)timestamp / AV_TIME_BASE);