AC3 alternative is bad news

[B.J.]

Be thankful when you run into channels that have AC3 audio, even if you're one of those who have problems playing it. At least there are ways for hobbiests to do AC3.
I just tuned in a FTA channel that I read about on another forum (can't give parameters), and this channel has what seems to be an mpeg alternative to AC3, in that there are 3 different audio PIDs, and each has different parts of the AC3 standard. Seems like L/R is on one PID, Center on another, and Surround on the third. Someone on the right of the screen talks to someone in the center, and on one PID you can hear the right individual, and on another PID you can hear the center individual. On the third PID, you generally hear background music/noise, but not much else. There is basically no way to hear all the sounds from the program from any one of the 3 PIDs. On this channel, some programs sound normal on one PID, and the other 2 are blank, but other programs give the wierd audio.
If this becomes more common, it will make most of our receivers obsolete. Perhaps we should put a request in to the Azbox people to create an option whereby multiple audio streams can be MIXED. I'm not sure how much processing this would require. Sounds like it would be easy on a file, but might not be practical real time, without losing sync.

 

[Anole]

sounds familiar (no pun):

I don't know how to search for info on this, but I've seen it reported before.
Unfortunately, I don't remember if there was a work around or any solution.
At least it's not Dolby E, eh? :rant:

 

[B.J.]

I don't know how to search for info on this, but I've seen it reported before.
Unfortunately, I don't remember if there was a work around or any solution.
At least it's not Dolby E, eh? :rant:

Yeah, re "E" .
If you remember where you saw mention of this before, please post. Only thing I've seen similar is the NBC stuff that has programming on one PID, and half the commercials on another PID, and I think there was stadium noise on a PID for football games, etc, but I think the actual programming had complete sound. This stuff is wierd.

 

[hd fan]

Sorry for hijacking but what is wrong with Dolby E being used? I remember an ESPN HD feed that used it (well it had that name on it) and still the audio was played perfectly through my ONKYO receiver. It showed it as Dolby Digital 2.0 so I thought that this Dolby E is somewhat backwards compatible or am I wrong?. I mean a Dolby Digital receiver will still play it fine as 2.0 (no 5.1 of course).

B.J , do not worry, most hobbiest have several receivers laying around just set each to a different PID add a couple of speakers to each and OFF you go , full sound for the show, lol. I guess it is a nice alternative to distribute the audio tracks for major events independently and gives the intended broadcasters the freedom to add their on audio to the show. For instance , lets say a channel like Telecaribe Colombia wants to broadcast the NYY baseball game, then they could add the spanish audio only to the background stadium sounds instead of end colombian viewers listening sometimes to the english commentators in the background which is annoying.

 

[zamar23]

Nothing is wrong with it in general, if Dolby E greatly improves sound quality, except there seems to be no mass volume FTA receivers currently on the market able to re-mux such signals in hardware to output via HDMI to a TV as PCM sound or via SPDIF for Onkyo like A/V Equipment to decode and play. It looks like there are 2 alternatives: the signal needs to be re-muxed & down-converted for older equipment, or being directly played via SPDIF or higher through-output new port type by a Dolby E supporting A/V Receiver with speakers. Re-muxing audio might be more suitable for Linux based STBs, as memory and proc limitations would make non-Linux STBs obsolete much faster, and most don't have space and extra power for more add-on cards, unless designed with such cards to be added later in mind.

 

[qwert1515]

Dolby E allows up to eight channels of audio. Currently there is no consumer equipment that can decode Dolby E.
If your AV receiver could play the audio it was playing another audio stream in the MUX.
Commercial equipment that can work with Dolby E has to be licensed from Dolby Labs which usually costs a few thousand dollars

 

[hd fan]

thanks Qwerty, I guess It was just then the name on the channel then. Since it was coincidently DD 2.0 and Dolby E is a way of transmiting up to 8 channels as only 2 channels I thought that maybe Dolby E was also backwards compatible with DD 2.0 and that that was why the receiver was able to play the audio. I guess It was not Dolby E after all. this was just a ESPN HD sport feed so maybe previously they were using Dolby E and they forgot to update the name of the channel/feed.

I found this about the new facility for PBS affiliate WTVI:

" With its cuttingedge facility already designed for Dolby E, WTVI is also ready for future PBS network audio feeds that will be in Dolby E. "
end of quote

So we should expect to see more major broadcasters to use this Dolby E audio on their feeds in the future. not good news for us of course.​

 

[madmadworld]

this has been around a bit and $$ on the ends in these times.
i worry more about fiber.

 

[stogie5150]

Be thankful when you run into channels that have AC3 audio, even if you're one of those who have problems playing it. At least there are ways for hobbiests to do AC3.
I just tuned in a FTA channel that I read about on another forum (can't give parameters), and this channel has what seems to be an mpeg alternative to AC3, in that there are 3 different audio PIDs, and each has different parts of the AC3 standard. Seems like L/R is on one PID, Center on another, and Surround on the third. Someone on the right of the screen talks to someone in the center, and on one PID you can hear the right individual, and on another PID you can hear the center individual. On the third PID, you generally hear background music/noise, but not much else. There is basically no way to hear all the sounds from the program from any one of the 3 PIDs. On this channel, some programs sound normal on one PID, and the other 2 are blank, but other programs give the wierd audio.
If this becomes more common, it will make most of our receivers obsolete. Perhaps we should put a request in to the Azbox people to create an option whereby multiple audio streams can be MIXED. I'm not sure how much processing this would require. Sounds like it would be easy on a file, but might not be practical real time, without losing sync.

I THINK the young man here is talking about the NBC Muxes on AMC 1 and AMC 18 C-band. You can talk about those here, BJ, they are on Lyngsat, no foul.

And yeah, their audio IS screwy. But it better than the stunned silence of a dolby E ONLY feed...

 

[tvropro]

I THINK the young man here is talking about the NBC Muxes on AMC 1 and AMC 18 C-band. You can talk about those here, BJ, they are on Lyngsat, no foul.

And yeah, their audio IS screwy. But it better than the stunned silence of a dolby E ONLY feed...

Ya that would be the muxes didn't want to say anything here but if it's okay. Dolby E from what I heard needs some big expense equipment to decode it.

 

[truckracer]

everybody's brother in law and friends will one day have a receiver that can decode dolby e.

 

[B.J.]

I THINK the young man here is talking about the NBC Muxes on AMC 1 and AMC 18 C-band. You can talk about those here, BJ, they are on Lyngsat, no foul.

And yeah, their audio IS screwy. But it better than the stunned silence of a dolby E ONLY feed...

Like I said in earlier post, I've listened to those NBC things, but they didn't seem nearly as bad as the channel I was referring to, however the particular program I was watching was a cartoon, and therefore had somewhat artificial audio, in that they could put one character's voice on one PID, and the another character's voice on another PID. Really wierd to hear one character talk from the right, then the character in the center's mouth would move but absolutely no sound. Seems like on the NBC channels the programs were still watchable, just that the levels were messed up. (I feel a bit silly acting surprised that a cartoon character's mouth moved but no sound came out.)

I guess the previous idea about using multiple receivers could work. I could do one PID with the TV, one with the stereo, but I'd have to install another audio system to get the third channel. But I'd expect some echo chamber effects since each receiver has it's own delays involved. However this would only work for live viewing. If I record a program, I'd only be able to play back one audio stream, unless there are video players that can mix audio streams.

 

[hd fan]

Althought there will be different delays for different receivers I do not think there will be an echo chamber effect at all , provided that every Audio PID carries a totally different audio. Besides the delays will be so minimal and unoticeable probably. who cares if the second caracter has a minimal delay to their mouth movement (using your own cartoon example) as long as you can at least listen to what it says. A/V receivers also has settings for audio delay so you could actually delay the fastest one to compensate but it will make to expensive the solution. I was just thinking on using powered PC speakers along with extra receivers , as you said you could even use the TV speakers.

On the PVR funtion if you use a VCR (instead of the PVR function of the STB) then you could first mix the 3 audio PIDS with some sort of audio mixer or as a poor's man resort just put a mic in the center of the living rm and then record that audio as the VCR input (do not output that audio otherwise you will get feedback noise). Well any other extra sounds generated in your home will get recorded as well , but wouldnt you hear it anyways were you have been watching the show live? who cares then?.

not perfect but better than silence with dolby E or only 1 sound, eh?