Opened 9 years ago

Closed 9 years ago

#8839 closed defect (Invalid)

DTS Passthrough stutters/choppy/laggy on trunk and if unchecked then crashes playback

Reported by: mitch.capper@… Owned by: JYA
Priority: major Milestone: unknown
Component: MythTV - Audio Output Version: Master Head
Severity: medium Keywords: DTS, stutter, SPDIF
Cc: Ticket locked: yes

Description

I am using trunk(25907) and when I play a video in mythvideo with DTS I run into an issues. My setup is set to ALSA:iec857:CARD=intel,DEV=0 for audio output device with DD and DTS checked and speaker config on 5.1 without upconverting checked. Playing normal media is fine but when playing something with DTS while the receiver is showing DTS received the audio stutters heavily (multiple times a second I would say). Playing through mplayer with -afm hwac3 has the DTS audio working just fine.

Playback without DTS enabled also works fine.

*) if Stereo mode is enabled instead of 5.1 (as spdif can't pass standard surround I believe) audio works giving stereo sound but no DTS is passed through (even though its checked) *) If DTS is unchecked but Dolby Digital is left checked (some suggested this would convert between the two) I just get lots of entries of: getBufferedOnSoundcard() called with pcm_handle == NULL followed by: 2010-08-29 10:08:35.156 Player(4): Waited 100ms for video buffers AAAAAAaAAAAALaaaL Several times

in the log and no audio and video does not even play. Dolby Digital encoded items however do play fine (and receiver shows it as receiving DD signal)

I tried various debug modes but don't see anything that would seem to hint towards why there is a stutter.

Attachments (3)

dts_playback_attempt.txt (4.9 KB) - added by anonymous 9 years ago.
mythlog_vaudio_vplayback.log (16.7 KB) - added by anonymous 9 years ago.
mythfrontend.log (28.1 KB) - added by mitch.capper@… 9 years ago.
Dec 11 log.

Download all attachments as: .zip

Change History (22)

comment:1 Changed 9 years ago by robertm

Status: newassigned

comment:2 Changed 9 years ago by mitch.capper@…

Sorry I noticed there was a contradiction there, I said playing without DTS enabled also works fine, i meant without any pass through enabled not just without DTS checked.

comment:3 Changed 9 years ago by JYA

Status: assignedinfoneeded

Could you please provide some logs with the -v audio options?

comment:4 Changed 9 years ago by anonymous

The good news is that trunk fixed it so unchecked DTS but checked DD does infact now convert from DTS->DD so it is watchable in surround sound now (just not the native format). I attached a log of mythfrontend with -v audio sadly still stutter, between 10:15:49 and 53 is when its playing.

Changed 9 years ago by anonymous

Attachment: dts_playback_attempt.txt added

comment:5 Changed 9 years ago by Nicolas Riendeau

Status: infoneededassigned

comment:6 Changed 9 years ago by JYA

Status: assignedinfoneeded

Please try with a recent version of trunk (e.g today), and report if you are still seeing an issue. It's likely to be fixed

comment:7 Changed 9 years ago by anonymous

I actually synced right before doing the tests, it may have been what fixed the DTS->DD conversion but does not seem to have fixed this version info:

MythTV Version : 26257M MythTV Branch : trunk

comment:8 Changed 9 years ago by anonymous

Sorry meant to say did not fix the stutter.

comment:9 Changed 9 years ago by Kenni Lund [kenni a kelu dot dk]

Status: infoneededassigned

comment:10 Changed 9 years ago by JYA

Status: assignedinfoneeded

But does it crash if DTS is unchecked ? I see no error of any kind in the log provided. The audio is going as passthrough as it should. As far as the audio is concerned, the audio stream was sent out perfectly okay

Please resubmit a log showing the problem, add -v audio,playback this time.

BTW: "Playing through mplayer with -afm hwac3 has the DTS audio working just fine.", this is not the option to play with DTS passthrough it's hwdts

comment:11 Changed 9 years ago by anonymous

Sorry as I said above if DTS is unchecked but DD is checked it does properly convert to DD now, this may be result of syncing today to head. The -afm hwac3 actually is DTS if there is DTS (and receiver shows DTS) -af hwac3 is AC3 only.

Attached is log with both verbose options.

Changed 9 years ago by anonymous

comment:12 Changed 9 years ago by JYA

There are no errors of any kind or playback issues in this log. As far as myth is concerned, it has passed the DTS stream straight to the digital interface.

I'm happy to test your test.mkv file but as far as I'm concerned, the issue has to be outside myth or your PC and with your amp

comment:13 Changed 9 years ago by JYA

BTW, go back in the audio configuration page, and set up a device as detected by myth after pressing the detect button.

You are using a custom audio output device (IEC858:{ 0x02}) , which is certainly not what myth would have returned

comment:14 Changed 9 years ago by anonymous

I have tried a few different DTS files (I don't have a huge selection) but it seems to happen on all of them. As mentioned mplayer passes the DTS through just fine. In addition I also have DTS headphones which I can also plug directly into the optical out on the box and they have the same stutter issues.

comment:15 Changed 9 years ago by JYA

please provide test.mkv

And properly configure the audio settings. Your original comment says that you are using 'ALSA:iec857:CARD=intel,DEV=0'

You aren't. You are using hw:0,2 for audio playback and IEC958:{ 0x02} for digital passthrough

comment:16 Changed 9 years ago by robertm

Resolution: Invalid
Status: infoneededclosed

No response in 5 weeks.

comment:17 Changed 9 years ago by mitch.capper@…

I had tried both for audio, recently setup mythtv on a new machine, new motherboard manufacturer, 64 bit over 32, and an Xonar DX sound card with optical out (so different chipset). Sadly the same issue happens. Running latest trunk: Revision: 27420. I have attached another log with -v audio,playback enabled. This is playing the 50 megabyte DTS MKV sample file at: http://rapidshare.com/files/436402017/test.mkv

(Although I have the issue on any DTS MKV file I have). All of the hardware has changed and software reinstalled.

Changed 9 years ago by mitch.capper@…

Attachment: mythfrontend.log added

Dec 11 log.

comment:18 Changed 9 years ago by mitch.capper@…

Resolution: Invalid
Status: closednew

comment:19 Changed 9 years ago by JYA

Resolution: Invalid
Status: newclosed
Ticket locked: set

This is a different issue. Lodge a new bug

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