Bug #2701

Dolby Digital audio is passed through as DTS. It creates green artifacts in video playback

Added by . . over 5 years ago. Updated over 5 years ago.

Status:FixedStart date:06/21/2015
Priority:NormalDue date:
Assignee:Andreas Smas% Done:

100%

Category:Video playback
Target version:4.10
Found in version:4.9.559 and before Platform:PS3

Description

Most TVs nowadays support these HDMI audio formats: DTS, Dolby Digital, PCM (Up to 192 KHz,
32k/44.1k/48k/88k/96k/176k/ 192k. Even if the TV only has 2.0 sound, the DD and DTS sound is digitally passed to the TV, then converted to analog by the TV or passed through again to another audio system.

Movian identifies DD as DTS, and this creates a lot of problems during video playback. The image flickers with huge green artifacts. A workaround is to disable DTS over HDMI in the PS3 audio options, leaving only DD and PCM checked. The problem is that I loose the digital DTS signal in movies and games.

So please fix this problem, it's easy to spot. You can play a DD AC3 5.1 track and the TV info shows DTS and video playback is really bad.

Associated revisions

Revision f98e47b3
Added by Andreas Smas over 5 years ago

ps3: Prefer DD/AC3 output before DTS

refs #2701

Change included in version 4.9.578

History

#1 Updated by . . over 5 years ago

Edit: Platform is PS3

#2 Updated by . . over 5 years ago

I've been testing it further.

Playing DTS content with DTS over HDMI enabled in the PS3 audio options creates the same artifacts. Movian identifies DTS as DTS (obviously), but the video playback is full of artifacts.

If I disable DTS in the PS3, Movian plays DTS fine, but the TV shows it as DD digital sound over HDMI (weird). Games with DD 5.1 and DTS work fine. Blu-Rays and DVDs work fine too using the PS3 media player.

#3 Updated by Andreas Smas over 5 years ago

  • Status changed from New to Need feedback

Read this:

https://movian.tv/projects/movian/wiki/FAQ#section-14

I've not figured out a way for Movian to do digital pass thru so it needs to always decode the audio to PCM and then the PS3 operating system will re-encode it again using the configuration from XMB combined with the capabilities adviced by the device at the other end of the HDMI cable. In other words, if the content is encoded with DTS or AC3 makes no difference to what's output over the HDMI cable. It's always decoded and re-encoded again. And i've settled for it to always prefer DTS output if the TV supports that and that's enabled in the XMB because AFAIK DTS offers better quality. But the best choice would be for the user to select PCM as that does not cause any re-encoding again and thus offers the best audio quality.

That said it should not cause any image degradation. Does this happen for you on all movies? Or is it only when having multi-channel output? I've to admit that I haven't tested my PS3 with multichannel output for a while.

#4 Updated by . . over 5 years ago

It happens to all movies, and only using Movian. Both DTS and DD pass trhough work fine in PS3 Games and PS3 Blu-Rays.

There is a problem with the Movian re-encoded DTS. The format is not good, because the artifacts could be created by the TV. Sometimes I get a message "Incorrect format" and no sound or image. That's because this re-encoded DTS is not standard or there is something wrong with this DTS+video stream.

DD work fine in Movian using the same process, but I have to disable DTS in the PS3. So, some ideas:
1. Fix the DTS problem if you can find what is causing it. DD works fine, so maybe it's easy to spot.
2. Do not force DTS when the source is DD. DD to PCM to DD and DTS to PCM to DTS. Could it help? It wont hurt anyway.
3. Add an option in Movian to force PCM, DD or DTS. Because now I have to force PCM (+DD) at PS3 level, so I loose DTS in Games and Blu-Rays too.

Thanks.

#5 Updated by . . over 5 years ago

I forgot to say, the option 3 could be a selection with multiple options like in the PS3 audio options, not just forcing one.

#6 Updated by . . over 5 years ago

I've been doing more tests, and it does not happen with mp3 or aac 2.0.

So it's DD 5.1 to PCM to DTS 5.1 and also DTS 5.1 to PCM to DTS 5.1.

And again, DD 5.1 to PCM to DD 5.1 and DTS 5.1 to PCM to DD 5.1 both work fine.

#7 Updated by Andreas Smas over 5 years ago

asdasd asdasd wrote:

It happens to all movies, and only using Movian. Both DTS and DD pass trhough work fine in PS3 Games and PS3 Blu-Rays.

There is a problem with the Movian re-encoded DTS. The format is not good, because the artifacts could be created by the TV. Sometimes I get a message "Incorrect format" and no sound or image. That's because this re-encoded DTS is not standard or there is something wrong with this DTS+video stream.

DD work fine in Movian using the same process, but I have to disable DTS in the PS3. So, some ideas:
1. Fix the DTS problem if you can find what is causing it. DD works fine, so maybe it's easy to spot.

The DTS encoding is done by the PS3 operating system so I have no control over that, thus I can't change it. But it's weird that it works ok in games for you since I assume it's the same DTS encoder. Could it be a problem with 8 channel DTS, vs 6 channel DTS output perhaps?

2. Do not force DTS when the source is DD. DD to PCM to DD and DTS to PCM to DTS. Could it help? It wont hurt anyway.

This wouldn't help if the source material is DTS, the only upshot is that it would be less confusing to users since DTS will sent as DTS and DD as DD. However, it's still a bit of a lie since the material is re-encoded :-)

3. Add an option in Movian to force PCM, DD or DTS. Because now I have to force PCM (+DD) at PS3 level, so I loose DTS in Games and Blu-Rays too.

Maybe we should just default to DD instead? Adding more options / settings to work around various bugs is never a good idea I think.

Thanks.

#8 Updated by . . over 5 years ago

The DTS sources tested were 5.1. It's not just the PS3 DTS encoding or pass through, because it does it right in games (Uncharted uses both DTS and DD) and Blu-Rays.

And my TV is a high end 2013 model, it supports lots of stuff, it's updated and works always fine. It's only when using Movian with DTS output that complains with "Incorrect format" or shows artifacts.

Maybe using DD for DD and DTS for DTS could help. Al least movian with DD output works always fine. Does Movian decode DTS before the PS3 encodes it again? That's maybe the problem, something wrong with the PCM stream.

#9 Updated by Andreas Smas over 5 years ago

asdasd asdasd wrote:

The DTS sources tested were 5.1. It's not just the PS3 DTS encoding or pass through, because it does it right in games (Uncharted uses both DTS and DD) and Blu-Rays.

And my TV is a high end 2013 model, it supports lots of stuff, it's updated and works always fine. It's only when using Movian with DTS output that complains with "Incorrect format" or shows artifacts.

Maybe using DD for DD and DTS for DTS could help. Al least movian with DD output works always fine. Does Movian decode DTS before the PS3 encodes it again? That's maybe the problem, something wrong with the PCM stream.

Yes it decode all audio formats, that's what i'm trying to say.

The PS3 Game OS only accept PCM in its audio driver. There is AFAIK no way of passing raw DTS or DD bitstream using the conventional APIs.

I'm leaning towards defaulting to DD/AC3 as the default then. You also just said that 'DTS 5.1 to PCM to DTS 5.1.' also causes problems and then you suggest that 'DTS should be re-encoded as DTS', sounds like that wouldn't help.

#10 Updated by . . over 5 years ago

Could Movian be decoding DTS in a buggy way, so it creates the problem when it's coverted back to DTS by the PS3? Or maybe when it's merging back the audio and video stream.

There are video artifacts at the TV level, but the DTS sound is ok and the video playback is fluid too. It's like TV does not recognize the digital HDMI output as a completely valid format.

#11 Updated by Andreas Smas over 5 years ago

  • Target version set to 4.10

#12 Updated by Andreas Smas over 5 years ago

Please check 4.9.578 and see if it works OK for you.

It should now prefer DD instead of DTS

#13 Updated by Leonid Protasov over 5 years ago

99% that something is broken on your side. That can be poor cable, broken hdmi port. Firmware of tv or port on ps3. Try to replace hdmi cable. Update fw. Change hdmi port...

#14 Updated by Rural Hunter over 5 years ago

I have never seen such problem when playing videos with DTS audio on my PS3/Movian

#15 Updated by Rural Hunter over 5 years ago

Btw, what's DTS setting on PS3 OS do you guys talking about? I remember the audio ouput of PS3 only has the option of bitstream/PCM. I have no probem with both options.

#16 Updated by . . over 5 years ago

Rural Hunter: That's why you cannot detect anything wrong, your TV does not support DTS or DD pass through. The PS3 autodetect this modes, you cannot force them if you don't haven them available, you can only deselect them. You only have PCM audio in your PS3, so you cannot check this problem.

Cable is fine, firmware is fine, everything is fine with PS3 Games and Blu-Rays. It's just Movian with DTS.

#17 Updated by . . over 5 years ago

Andreas Ă–man: 4.9.578 works fine.

#18 Updated by Leonid Protasov over 5 years ago

  • Status changed from Need feedback to Fixed
  • % Done changed from 0 to 100
  • Platform changed from Linux to PS3

#19 Updated by Rural Hunter over 5 years ago

Ok, I understood. I think it's your TV problem. My PS3 is connected with a A/V receiver. It of course supports DTS/DD etc.

asdasd asdasd wrote:

Rural Hunter: That's why you cannot detect anything wrong, your TV does not support DTS or DD pass through. The PS3 autodetect this modes, you cannot force them if you don't haven them available, you can only deselect them. You only have PCM audio in your PS3, so you cannot check this problem.

#20 Updated by . . over 5 years ago

Rural Hunter: In the PS3 menu, go to options, audio, and select automatic. Tell me all the audio modes other than "PCM - XXX" your PS3 detects. Maybe it only happens in some TVs or standalone A/V recievers, but the problem was there with DTS, and only using Movian. If I ever had a single problem using something else I could say there's something weird with my TV.

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