Opened 7 years ago

Closed 6 years ago

#12187 closed Patch - Bug Fix (Fixed)

UPnP - Fix broken FFWD/REW/JUMP in playback for LG SmartTV DLNA clients for recordings with startoffset

Reported by: ludvik.tesar@… Owned by: dblain
Priority: minor Milestone: 0.28
Component: MythTV - UPnP Version: Master Head
Severity: medium Keywords:
Cc: Ticket locked: no


I would like to propose this simple fix that affects some LG SmartTV DLNA clients. This fixes error in playback navigation through FFWD/REW buttons and through the navigation bar. The patch replaces dtProgStart by dtStartTime in the query into recordedmarkup table.

The patch is at :

Description of the bug : If the recording is recorded with non-zero startoffset, the playback navigation in DLNA client is then completely broken. If you Jump forward (with FFWD button) or jump backward (with RWND button) or you navigate through the recording using the navigation bar, the playback jumps to the position that seems not to be related to where you intended to jump. Sometimes forward jump might go backwards and vice versa. It is quite frustrating. Consequently, WAF is completely ruined.

Afected clients : LG SmartTV series 2012, probably also other series that share the same code, 2011 and 2013. Windows Media Player is not affected.

Cause : This behaviour is caused by wrong duration attribute of <res/> tag, which is calculated from EIT data rather than from the real mpg file playback duration. This is because playstart is used instead of starttime in the query to recordedmarkup, so the query fails and as fallback, record.progend - record.progstart is used as duration. The client expects the duration value to be precise, otherwise jumping to position is broken.

It is clear that the bug is there since 2006, since the first time UPnP was added and it is still in master branch. It was probably not so apparent in past, since not so many clients use the duration attribute for anything.

I have tested this well with current stable build from mythbuntu :

MythTV Version : v0.27.1-15-g050bf9d MythTV Branch : fixes/0.27 Network Protocol : 77 Library API : 0.27.20140520-1 QT Version : 4.8.4 Options compiled in:

linux profile use_hidesyms using_alsa using_oss using_pulse using_pulseoutput using_backend using_bindings_perl using_bindings_python using_bindings_php using_crystalhd using_dvb using_firewire using_frontend using_hdhomerun using_ceton using_hdpvr using_ivtv using_joystick_menu using_libcec using_libcrypto using_libdns_sd using_libfftw3 using_libxml2 using_lirc using_mheg using_opengl using_opengl_video using_qtwebkit using_qtscript using_qtdbus using_sdl using_taglib using_v4l2 using_x11 using_xrandr using_xv using_profiletype using_bindings_perl using_bindings_python using_bindings_php using_mythtranscode using_opengl using_vaapi using_vdpau using_ffmpeg_threads using_mheg using_libass using_libxml2

Change History (2)

comment:1 Changed 7 years ago by J.Pilk@…

I just rebuilt v0.27.1-15-g050bf9d with a patch that added this to the reversion of the patch from #9446 that I reported in #12181. Now playback of recordings via uPnP is excellent and navigation within them is effective, in my case (Panasonic) by a 5-speed FF/RW control. The duration of the recording is correctly displayed, both before and after cutting, as is the current position, both digitally and on the progress bar. Tested with DVB-T/T2 recordings in the UK.

comment:2 Changed 6 years ago by stuartm

Milestone: unknown0.28
Resolution: Fixed
Status: newclosed

Fixed in master

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