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Dual channel audio, what is possible ?


gabier

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Hello,

 

The answer is maybe obvious, but I could not find it.

 

The french-german TV station Arte started a service for some movies with so-called "bi-canal" (dual channel) audio. This means that you can choose the dubbed version or the original version with subtitles.

The instruction for regular DVB-T users (DVB-T adapter + TV set) are (I translate from french) :

"

1) Audio : Generally, DVB-T adapters give access to different audio versions through only one key of the remote : "Audio I/II" or "A/B".

2)Subtitles : The subtitles are obtained directly with "DVB subtitling" (in english in the french text)through either a key on the remote or the key Menu or Setup of the adapter.

"

I did not know it was possible to have several audio flux with MPEG-3 DVB-T, but obviously it is, and regular TV user can display them.

So how is it possible to display these channels with my Hauppauge Nova-T-USB2 tuner and DVBViewer ? Is it a tuner problem or a DVBViewer problem ?

 

Any idea ???

 

Gab

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There are two ways to broadcast different audio tracks:

 

- As separate streams, each one with its own audio PID. Select them in DVBViewer with Settings -> Audio

 

- As one stream, right channel with the dubbed version, left channel with the original (that's dual channel, a kind of abused stereo). Select them with Settings -> Balance.

 

If you want to output the left or right channel to both speakes, you'll need the RadLight Audio Selection Filter (see members area -> plugins, RLAudioSel.ax). Store it in DVBViewer\Filters and register it with the RadLight Filter Manager (DVBViewer should be closed) - get it from the members area -> main application section.

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Arte on the french dvb-t (TNT) network is taken from the feed on Atlantic Bird 3; 5W, 11591V

There are seperate audio streams in german and french as well as the corresponding dvb subtitle streams.

 

Program Number: 7/261 ARTE

Stream Type: 0x02 MPEG-2 Video PID 520 (0x0208)
MPEG Video: Bitrate 15.000 Mbps Resolution 544 x 576i
MPEG Video: Framerate 25 fps Aspect Ratio 16:9 Chroma Format 4:2:0
Descriptor: STD Descriptor
Leak Valid Flag: 1

Stream Type: 0x03 MPEG-1 Audio PID 530 (0x0212)
MPEG1 Audio: Bitrate 192 Kbps Sample Rate 48 KHz
MPEG1 Audio: Layer II Mode Joint Stereo
Descriptor: ISO639 Language Descriptor
Language: fra
Audio type: undefined

Stream Type: 0x03 MPEG-1 Audio PID 531 (0x0213)
MPEG1 Audio: Bitrate 192 Kbps Sample Rate 48 KHz
MPEG1 Audio: Layer II Mode Joint Stereo
Descriptor: ISO639 Language Descriptor
Language: deu
Audio type: undefined

Stream Type: 0x06 ISO/IEC 13818-1 PES packets containing private data PID 541 (0x021d)
Descriptor: Subtitling Descriptor

Stream Type: 0x06 ISO/IEC 13818-1 PES packets containing private data PID 542 (0x021e)
Descriptor: Subtitling Descriptor

Stream Type: 0x06 ISO/IEC 13818-1 PES packets containing private data PID 540 (0x021c)
Descriptor: Subtitling Descriptor

 

btw. some audio decoder can switch between different modes.

 

 

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There are two ways to broadcast different audio tracks:

 

- As separate streams, each one with its own audio PID. Select them in DVBViewer with Settings -> Audio

 

Thank you Griga for this very clear tuto. The first way is the real one, I think. I understand now how it works and I found the data in the channel list of DVBViewer. In fact there are 2 channels on the same frequency

1) Arte (deu) channel 884: Stream ID 1, Video PID 520, Audio PID 531

2) Arte (fra) channel 883 : Stream ID 1, Video PID 520, Audio PID 530

Usually they use the audio streams one for german and one for french, and I guess that when they broadcast a movie in a so-called Multilingual Version, they use one for the dubbed version and one for the original one. It probably is as simple as this.

There is a multilingual braoadcast on monday night, I will check it, and find out which channel is the dubbed one.

 

Thanks :bye:

 

Gab

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Arte on the french dvb-t (TNT) network is taken from the feed on Atlantic Bird 3; 5W, 11591V

There are seperate audio streams in german and french as well as the corresponding dvb subtitle streams.

 

Thank you Derrick, your post and my reply to Griga crossed each other. I understand now how it works, at least for audio streams.

One thing though. I can switch languages in DVBViewer with the Settings->Audio Menu, but the menu Settings-> Subtitles has no effect. Maybe this is normal and there is no subtitle in normal periods, only when broadcasting a "multilingual" movie.

I will find this out on monday, there is a "multilingual " broadcast.

 

Thank you

 

Gab

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ok, you'll have to check on monday. Maybe the will split the stereo channels in dual channels with german/french and the original audio. I figured out that the settings of my intervideo decoder doesn't have any effect :bye:

 

btw.

 

In fact there are 2 channels on the same frequency

1) Arte (deu) channel 884: Stream ID 1, Video PID 520, Audio PID 531

2) Arte (fra) channel 883 : Stream ID 1, Video PID 520, Audio PID 530

It is just one channel with different audio and subtilte streams. Only DVBViewer sees two channels (due to legacy settings) ;)

 

The subtitle streams are active all the time but only show subtitles when necessary.

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ok, you'll have to check on monday. Maybe the will split the stereo channels in dual channels with german/french and the original audio.

 

Yes, on DVBViewer, everything was OK, there were 2 audio streams. The stream "French" gave dubbed version in french, and the stream "German" gave the original sound track in english. There was also a subtitles stream which could be activated.

 

But problems appear after recording. In the mpeg file, if I play it with Video Player Classic (I am not yet used to Nero Home, one has access to nothing in it, Nero Showtime was more pleasant), I have only the french audio and no subtitles. Were the 2 missing streams not recorded (that seems to me impossible) or do I not find them ? How to know ? How did you analyse the Arte streams in your post ?

 

Gab :bye:

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But problems appear after recording. In the mpeg file, ... I have only the french audio and no subtitles. Were the 2 missing streams not recorded (that seems to me impossible) or do I not find them ? How to know ?

Recording in mpeg was probably the wrong choice. Whether all audios are recorded, you can find out with the TSPlayer. Dunno if the subtitles are in a separate file but they are not multiplexed into the program stream (mpeg).

 

Next time you’d better check transport stream as recording format with all substreams. For the analysis of the stream I used tsreader but everything can be seen with the analyzer function of TransEdit :bye:

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Recording in mpeg was probably the wrong choice. Whether all audios are recorded, you can find out with the TSPlayer.

 

There is indeed a wrong choice somewhere because I downloaded TSPlayer (I do'nt see it in DVBViewer but it works as standalone ) and actually there are only one videostream and one audio stream.

I understand now that DVBViewer recorded only the "channel" I asked for, and this is one of the "channels and its audio stream.

 

Next time you’d better check transport stream as recording format with all substreams.

 

How can I do this ? Must I record in TS format ? But

1) I did not see in DVBViewer how to perform this.

2) Once in TS Format, what about my processing chain, which worked well until now ? I use VideoRedo, it reads .ts, but do I go on with .ts for my authoring soft which is NeroVision, and will it support 2 audio tracks ? Lot of question to solve... :bye:

 

An additionnal one : to analyze the transport stream, did you record it as .ts and then read it with TSPlayer ?

 

Thanks to help me at least with the good format to record with and how to do this with DVBViewer.

 

Gab :bye:

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See Settings -> Options -> Recorder -> Recordings.

 

DVBViewer 3.6 is able to record two or more audio streams in MPG files (not only TS) - tick the according checkbox in the options. However, whether other software is able to read them or not... dunno :bye: Try it with two short test recordings, one TS and one MPG, and find out what works best.

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See Settings -> Options -> Recorder -> Recordings.

 

Arghhhh ! Me :bye: I had not seen them because they are in the root "Settings -> Options -> Recorder" and not in "Settings -> Options -> Recorder -> Recordings"

 

But I am a little confused about what will exactly DVBViewer record. My 2 stations are

 

Nb 38 ; Name : Arte (fra); Video PID : 520; Audio PID : 530; Serv. PID : 261; PMT PID : 510; PCM PID : 520

Nb 39 -----------Arte (deu)---------------520----------------531---------------261---------------510-------------520

 

Thus my 2 stations share all the streams, except audio (there are also other stations on this transmitter but no stream is shared with them).

I want to record a file with streams video 520, BOTH audios 530 and 531, and subtitles (are they in the Services stream ?). What is to be recorded ? In the DVBViewer scheduler, if I specify station 38 with "all audios" ticked, nevertheless it will not record stream 531, and if I specify 38 AND 39, I will have 2 files with video and maybe subtitles in both. Am I wrong ? If not I can only record the 2 stations then demux them and remux the correct streams. True ? I yes I am not yet out of the wood ! :bye:

 

Thanks for any idea which could go towards more simple perspectives.

 

Gab :)

Edited by gabier
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Thus my 2 stations share all the streams, except audio

In reality your 2 stations is just one single station with a plurality of elementary streams including the 2 audio (and subtitles, teletext etc).

 

It's the DVBViewer that makes 2 out of one and the devs. don't want to change this to dvb-style :bye:

 

For recording purposes the audios are seen as streams of a single programme. This is not logic but it is as it is. To check how it looks in the realm of DVB, use transedit's analyser. That is one of the best tools in field and imho by itself much more worth than the 15€ for the entire package :)

 

IF you want to process your recordings further to author DVDs or whatever, I strongly recommend TS as recording format. Though the DVBViewer can mux 2 or more audio streams into mpeg, each multiplexer reflects the philosophy of its programmer :) Besides no dvb-subs are muxed into mpeg! With TS you'll have everything as close as possible to the original and for a authoring tool the streams have to be demultiplexd to single elementary streams anyway. Then you can author a DVD with different audio tracks and subtitles :bye:

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In reality your 2 stations is just one single station with a plurality of elementary streams including the 2 audio (and subtitles, teletext etc).

Thanks Derrick for this help,

OK, I understand how it is made inside the DVB stream, but not what DVBViewer makes out of it when recording.

In my case, suppose there is an american movie dubbed in french broadcasted in France in "multilingual version"

Then Arte (fra) is supposed to broadcast the dubbed version (french audio track) and Arte (deu) the english audio track and subtitles. Of course this is a logical view, and physically all the tracks are available.

 

Now I choose in the recording settings TS files and I tick "all audio streams" and "subtitles". Then, in the scheduler I schedule the recording of Arte (fra).

 

What will be recorded ? video + french track only, OR video + french track + english track + subtitles OR some other combination ?

 

Same question if now I schedule the recording of both "logical" channels, Arte(fra) and Arte(deu) (with same settings) ?

 

Do you think I will finaly understand everything ? :bye:

 

Gab

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What will be recorded ?

You don't have to worry if you've checked TS with teletext, dvb subtitles and all audio streams. In this recording mode DVBViewer behaves like a dvb-device should behave :bye: The SID (program number) leads to a table (PMT) in which all streams are listed with their PIDs. When tuned to the channel the table is examined and all useful streams found will be recorded. The TS is a filtered (PIDs) part of the entire stream from the transponder.

 

If you would choose mpeg, the PIDs would be taken from the channel list, which represents the moment when the list was established. Though you could use auto-update for dynamically updating the channels, this will only work for already existing audio streams. E.g. an ac3 stream that was not in the PMT during scanning won't be added cos there is no corresponding channel. This is not state of the art but if you use TS everything from the PMT will be in you recording.

 

..maybe too complicated ?? :bye:

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You don't have to worry if you've checked TS with teletext, dvb subtitles and all audio streams. In this recording mode DVBViewer behaves like a dvb-device should behave :bye: The SID (program number) leads to a table (PMT) in which all streams are listed with their PIDs. When tuned to the channel the table is examined and all useful streams found will be recorded. The TS is a filtered (PIDs) part of the entire stream from the transponder.

I think I understand. Just a point : is the SID a DVBViewer entity only or is it also in the DVB stream ?

 

If I interpret correctly, you think then that Arte (fra) and Arte (deu) have the same PMT thus if I ask for the recording of the first one, the streams of both will be recorded. Is that it ?

 

OK, the next VM broadcast is on monday, this time I will record a bit of both "stations" in TS format, and look what is inside with TS player. I will let you know the result.

 

..maybe too complicated ?? :bye:

Not at all, I learn plenty :)

 

Gab

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is the SID a DVBViewer entity only or is it also in the DVB stream ?

It's DVB or better mpeg ISO 13818-1 which is for a great deal the basis of dvb (except for modulation and some other stuff).

 

The SID (Service ID but officially it is called "program number") is a unique 16 bit number identifying a program (261 in our Arte example)

 

Nb 38 ; Name : Arte (fra); Video PID : 520; Audio PID : 530; Serv. PID : 261; PMT PID : 510; PCM PID : 520

btw. this notation is not quite correct cos the SID is not a PID. PID (packet identifier) is a 13 bit address in the header of a ts_packet. The PID is used to find and to filter packets of the same stream. You'll also find 261 in my anaysis at the beginning of this thread :bye:

 

If I interpret correctly, you think then that Arte (fra) and Arte (deu) have the same PMT thus if I ask for the recording of the first one, the streams of both will be recorded. Is that it ?

That is correct. If you look at the 2 arte programs in the DVBViewer's channel list, you see identical SIDs and PMTs. The only thing that differs is the audio PID. As I pointed out, this is DVBViewer-style :)

 

Sometimes you'll find different names for the same thing in dvb. Identical PIDs for video and audio are allocated to different programs with different names, SIDs and PMTs. This looks redundant but these services can split at certain times into regional programs with different PIDs for video and audio. Then viewers don't have to retune to watch their local news :bye:

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Thank you Derrick, this time I think I understood everything... until next time. :bye:

 

You are really helpful and very patient.

 

I will post the results of Monday's "multilingual" recording.

 

Gab :bye:

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I will post the results of Monday's "multilingual" recording.

 

There they are, with confirmations and new questions.

 

The confirmation is that, as Derrick said, the TS format includes everything necessary, and the elementary streams seam to be the same ones in both "stations" Arte (fra) and Arte (deu). There is a video stream, 2 audio streams and several subpic streams.

 

The question is that I have no good tool to handle these complex streams, wether to analyze them or to process them for authoring.

For the analysis, TSReader sees the 2 audio streams but not the subpics. I did not find the transedit program that Derrick recommended (there are several ones). I have also several players they usually react as TSReader, they do not see the subpics. One of them has a command "Load subtitles", but when clicked, error message : "You should have a video VMR7 or VMR9 renderless" (??).

The only way I found to be sure of all streams was to demux them. I used ProjectX, and indeed it demuxed with 1 video .m2v, 2 audios .m2p, 3 subpics .sup and 3 subpics images .sup.IFO. I do not really now what all these subpic streams are, and if all of them are useful. ;)

 

So the first question is : is there an analyzer of TS stream which could list all elementary streams and could allow to find out (maybe py "playing" each of them) what each of them is ? :(

 

Then, in order to use these streams and keep the multilingual structure, I have to demux and check them, cut unnecessary stuff, and author a DVD.

For the demuxing, I found the free software ProjectX. It seems to be an impressive demuxer, for checking I do not know, and it is not a very good cutter (not accurate at all), but it seems to cut all elementary streams.

For the cutting, I found Cuttermaran (another freeware), it seems very easy and efficient, but I think it does not handle subpictures.

For authoring, I am thinking of DVDLab Studio, it allows 2 audio streams and 1 subpicture stream (if one wants more he has to buy the pro version).

 

Any ideas here for all these tools (analyzer, demuxing, checking, cutting, authoring) ? ;)

 

Gabier

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is there an analyzer of TS stream which could list all elementary streams and could allow to find out (maybe py "playing" each of them) what each of them is ?

Sure. TransEdit. See members area (where you downloaded DVBViewer). Read the manual.

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Sure. TransEdit. See members area (where you downloaded DVBViewer). Read the manual.

 

Thank you Griga. I was rather looking for an analyzer of the TS file saved by DVBViewer recording. Is Transedit usable at the same time as DVBViewer records the same stream on the same DVB-T device (a Hauppauge WinTV-Nova-T-USB2) ?

 

Gabier

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I guess for your purpose pj.x will do as a single tool. You can demux and trim (or cut) everything in one go. Video is the reference and all other ESs will be aligned to the video time line. For me cutting at GOP boundaries is accurate enough ;)

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I guess for your purpose pj.x will do as a single tool. You can demux and trim (or cut) everything in one go. Video is the reference and all other ESs will be aligned to the video time line. For me cutting at GOP boundaries is accurate enough ;)

 

I don't fear a bad cut, but I fear for the wealth of my eyes, the preview is not accurate at all. ;)

If there is no other tool, I will do with it. :(

 

But what about the analyze of all these streams, in order to know what is what and what is to be kept ?

 

Gabier

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the preview is not accurate at all.

..agreed, navigation and preview could be better, but with the use of the slider and the nav. >>>, >>, > I get to the right offsets with a couple of mouse clicks. Then -> save cutpoints to file (if you want to use it later or change something) -> go ;)

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..agreed, navigation and preview could be better, but with the use of the slider and the nav. >>>, >>, > I get to the right offsets with a couple of mouse clicks. Then -> save cutpoints to file (if you want to use it later or change something) -> go :(

OK, If you use it, it should not be bad.

To-night, I will record a whole movie with 2 audios and subtitles, and process all the way to a DVD. It will take a few days because I have to download DVDLab and get used to it.

 

I will let you know the result. ;)

 

Gab ;)

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