Subtitles desynchronized with Bluray playback

[logic]

Summary of the bug: If an external subtitles file (I tried with an SRT file) is specified when playing back a br:// title, the subtitles do not appear at the correct times.

How to reproduce:

[C:\Subtitling]c:\mplayer\mplayer.exe br://1 -bluray-device D:\ -sub SongsOnly.srt -utf8 -ass -alang eng -ni
MPlayer Redxii-SVN-r37927-6.2.0 (x86_64) (C) 2000-2017 MPlayer Team
FFmpeg version: N-84044-g2c400ba
Build date: 2017-03-18 19:02:36 EDT

Playing br://1.
libavformat version 57.66.104 (internal)
src/libbluray/bluray.c:261: 00000.m2ts: no timestamp for SPN 0 (got 0). clip 524280-298832915.
src/libbluray/bluray.c:261: 00000.m2ts: no timestamp for SPN 0 (got 0). clip 524280-298832915.
TS file format detected.
src/libbluray/bluray.c:261: 00000.m2ts: no timestamp for SPN 0 (got 0). clip 524280-298832915.
VIDEO H264(pid=4113) AUDIO TRUEHD(pid=4352) NO SUBS (yet)!  PROGRAM N. 1
FPS seems to be: 23.976025
<vo_directx><ERROR>Your card doesn't support overlay
Opening video filter: [ass auto=1]
Opening video filter: [scale]
[ass] auto-open
[ass] Shaper: FriBidi 0.19.7 (SIMPLE)
[ass] Using font provider directwrite
==========================================================================
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
libavcodec version 57.83.100 (internal)
Selected video codec: [ffh264] vfm: ffmpeg (FFmpeg H.264)
==========================================================================
SUB: Added subtitle file (1): SongsOnly.srt
Load subtitles in br://
Load subtitles in C:/mplayer/mplayer/sub/
==========================================================================
Opening audio decoder: [ffmpeg] FFmpeg/libavcodec audio decoders
AUDIO: 48000 Hz, 2 ch, s32le, 0.0 kbit/0.00% (ratio: 0->384000)
Selected audio codec: [fftruehd] afm: ffmpeg (FFmpeg TrueHD)
==========================================================================
AO: [dsound] 48000Hz 2ch s16le (2 bytes per sample)
Starting playback...
Movie-Aspect is 1.78:1 - prescaling to correct movie aspect.
[swscaler @ 0000000001a8a4e0]bicubic scaler, from yuv420p to bgra using MMXEXT
[swscaler @ 0000000001a8a4e0]using unscaled yuv420p -> bgra special converter
VO: [directx] 1920x1080 => 1920x1080 BGRA
[ass] PlayResX undefined, setting to 384
A:  17.0 V:  16.6 A-V:  0.347 ct: -0.367  93/ 93 92% 28%  3.7% 56 0


           ************************************************
           **** Your system is too SLOW to play this!  ****
           ************************************************

Possible reasons, problems, workarounds:
- Most common: broken/buggy _audio_ driver
  - Try -ao sdl or use the OSS emulation of ALSA.
  - Experiment with different values for -autosync, 30 is a good start.
- Slow video output
  - Try a different -vo driver (-vo help for a list) or try -framedrop!
- Slow CPU
  - Don't try to play a big DVD/DivX on a slow CPU! Try some of the lavdopts,
    e.g. -vfm ffmpeg -lavdopts lowres=1:fast:skiploopfilter=all.
- Broken file
  - Try various combinations of -nobps -ni -forceidx -mc 0.
- Slow media (NFS/SMB mounts, DVD, VCD etc)
  - Try -cache 8192.
- Are you using -cache to play a non-interleaved AVI file?
  - Try -nocache.
Read DOCS/HTML/en/video.html for tuning/speedup tips.
If none of this helps you, read DOCS/HTML/en/bugreports.html.

A:  31.4 V:  24.6 A-V:  6.840 ct: -1.129 287/287 111% 24% 16.9% 248 0
[ass] fontselect: (Sans, 400, 0) -> ArialMT, 0, ArialMT
A:  36.8 V:  27.4 A-V:  9.426 ct: -1.146 351/351 114% 25% 20.1% 311 0

From this output, you can see that it displayed the first subtitle at frame 287, which at 24000/1001 FPS is 11.97 seconds in. However, the first entry in the SRT file is:

1
00:00:24,692 --> 00:00:27,402
♪ Love ♪

I will try to attach a screenshot showing the subtitle appearing at the incorrect time.

If the Bluray video is transcoded to a different format first, the subtitles apply at the correct time when that intermediate file is played back. I have only observed the synchronization problem with br:// playback.

[logic]

Subtitle scheduled for 24.692 seconds displayed 13 seconds into the video.