Showtime and direct audio output...

Added by Matteo Plazzer over 8 years ago

Andreas has released the new version that support audio multichannel output...In the comments he write "Note that due to how the PS3 audio frameworks applications can not output raw digital bitstreams.". It means that never the showtime will can passthru digital audio? And that all dolby/DTS track will be send to multichannel analog PCM signal to A/V receiver?


Replies (9)

RE: Showtime and direct audio output... - Added by Andreas Smas over 8 years ago

Yes, that's correct. So over HDMI where 8 channel PCM is available. Showtime will always do the decoding and output PCM.
This includes all multichannel formats supported by libav (DTS, DTS-HD, AC-3, EAC-3, Dobly True HD, AAC, and possibly some format i forgot about).

If you are using optical toslink output the PS3 will re-encode the audio to DTS (if configured in XMB) or AC-3 (if configured in XMB, but DTS is preferred)

So internally it will look like this

--- AAC --> [decoder in showtime]  ->                ------> [DTS encoder in PS3 audio framework] -> DTS encoded audio over optical
                                   ->                ->
                                   ->  5.1 channels  ->
                                   ->                ->
                                   ->                ->
                                   ->                ->


If the source format is 7.1 (DTS-HD or Dolby True-HD or whatever) the PS3 audio framework will downmix this to 5.1 audio.
If only 2 channel stereo output is available the PS3 will downmix to 2 channels (from both 5.1 and 7.1 audio)

I don't think there will be a perceived loss of quality in this process. But I haven't verified in detail.

This is the best I can do with what the PS3 audio framework offers. Not sure if the built-in player actually passes the digital audio in bit-exact fashion or if it does the same transcoding.

RE: Showtime and direct audio output... - Added by Matteo Plazzer over 8 years ago

Thx for the explaination Andreas....

RE: Showtime and direct audio output... - Added by Theo Jansen over 8 years ago

I'm a bit confused with the multichannel support. My ps3 is connected with HDMI to my receiver so i thinks that is the best way to connect it.
When i play a movie from my Synology NAS Showtime only see 1 audio track which named AC3 stereo. Even if there are more tracks availeble in the mkv movie Showtime shows me oneaudio track .
When Showtime says it's a stereo audio channel then my receiver thinks it too. The only way to get some multi channel sound is changing surround options on the receiver but i think the receiver is creating multi channel from de sterao channel thats Showtime put out.

Is it correct that Showtime named the output AC3, stereo? Or is this output the multichannel output with the wrong name?
Maybe a bug?

RE: Showtime and direct audio output... - Added by Andreas Smas over 8 years ago

Are you sure the file is AC-3 5.1? AC-3 support stereo too.

RE: Showtime and direct audio output... - Added by Theo Jansen over 8 years ago

Well i think i found what's wrong. I can't select different audio tracks. When a movie got more then one audio track, Showtime doesn't show all the tracks. It just shows one. Unfortunately when i tryed it this morning i randomly choose some movies with multiple tracks and with AC3 sterao tracks in first place.

I just tryed a movie with only 5.1 sound track and it works just fine. So the only problem left is choosing an audio track when a movie contains more then one audio track. Should i make a ticket for this problem Andreas?

RE: Showtime and direct audio output... - Added by Andreas Smas over 8 years ago

Please create a ticket. This should work. But i might have screwed something up..... (as always :)

RE: Showtime and direct audio output... - Added by Matteo Plazzer over 8 years ago

I'm very happy of the new audio feature ...only I've a question because I'm a bit confuse: it's right that the PS3 encode all audio track to DTS?

I've av receiver connected to optical link and when I play a video with an multichannel AC3 DolbyD or AAC audio track, the display of receiver switch always on DTS signal....(in the xmb I've flagged both AC3 and DTS....). If I play a stereo track on avreceiver display I can see correctly an normal STEREO signal ....

I THINK that native audio player works in a different way....when I used psms (without mencoder...), the ps3 recognized exactly the audio track type and then the avreceiver switched fine to DTS or DOLBYD ...
Anyway if the conversion of DOLBYD to DTS doesn't create a loss of quality I think this will not be a problem. ;-)

RE: Showtime and direct audio output... - Added by Andreas Smas over 8 years ago

Matteo Plazzer wrote:

I'm very happy of the new audio feature ...only I've a question because I'm a bit confuse: it's right that the PS3 encode all audio track to DTS?

I've av receiver connected to optical link and when I play a video with an multichannel AC3 DolbyD or AAC audio track, the display of receiver switch always on DTS signal....(in the xmb I've flagged both AC3 and DTS....). If I play a stereo track on avreceiver display I can see correctly an normal STEREO signal ....

Yes, this is exactly how it works. I could add some code that, if the source is ac-3, switch the ps3 to output ac-3 as well. but it would still need to be decoded and encoded internally.

I THINK that native audio player works in a different way....when I used psms (without mencoder...), the ps3 recognized exactly the audio track type and then the avreceiver switched fine to DTS or DOLBYD ...
Anyway if the conversion of DOLBYD to DTS doesn't create a loss of quality I think this will not be a problem. ;-)

I think so too. But i'm not sure. It's hard to tell. I guess the only way is to actually play some mp4 file with ac-3 and capture the digital output from the ps-3 and compare that the data is bit-exact.

But frankly, i just don't have the time nor motivation to work more on this. It's a lot better than it used to be, and i'm not even sure i can figure how to output raw bitstream. If it even can be done from LV2 gameos.

RE: Showtime and direct audio output... - Added by Stève Sikati over 3 years ago

hello everyone,
please is this still the same case for movian 5, i just bought a 5.1 soundbase and it only works through optical so i would like to know.
Will movian decrypt all audio track in my movies and re-encrypt them into DTS over optical link?
and how can i make that the ps3 layer that handles audio for PS3 applications (ps3 audio frameworkk you said) re-encrypt in AC3 5.1 intead? i just need to unflag DTS in the optical audio menu?

thank you

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