mkvtoolnix recognize ac3 audio as a video

[maudit]

hi, i've created 2 different ac3 tracks starting from the same DTSMA.
the fist with useac3to the 2nd with DME.

when I drag the useac3to ac3 into toolnix is all ok as ausual.
while if I drag the ac3 created with DME, toolnix recognize it as a video..

wth? pls help...

[johns0]

Paste a text output here from mediainfo of the affected audio file.

[maudit]

Paste a text output here from mediainfo of the affected audio file.

General
Complete name : E:\_track2_[eng]_DELAY 0ms.dts_PAL.640k.ac3
Format : AC-3
Format/Info : Audio Coding 3
Commercial name : Dolby Digital
File size : 553 MiB
Duration : 1 h 59 min
Overall bit rate mode : Constant
Overall bit rate : 644 kb/s

Audio
Format : AC-3
Format/Info : Audio Coding 3
Commercial name : Dolby Digital
Duration : 1 h 59 min
Bit rate mode : Constant
Bit rate : 640 kb/s
Channel(s) : 6 channels
Channel layout : L R C LFE Ls Rs
Sampling rate : 48.0 kHz
Frame rate : 31.250 FPS (1536 SPF)
Compression mode : Lossy
Time code of first frame : 00:00:00:00
Time code source : Stream
Stream size : 553 MiB (100%)
Service kind : Complete Main
Time code of first frame : 00:00:00:00 (23.976 fps), embedded in stream

[johns0]

When you put it into mkvmerge with the video does it mux properly?

[maudit]

here's a new mediainfo of an ac3 created with DME instead of useac3to.
but this this time I didn't change the framerate form 24p to 25p.

again recognized as a video, and if i mux it with the video, this warning appear on toolnix,
and not, it does not mux at all into the mkv.

I don't understand what is going on.. it has always worked, the only thing I've done recently is to upgrade mkvtoolnix to the latest version.

I'm now gonna try to downgrade toolnix to "mkvmerge v71.1.0 ('Fortitude') 64-bit"... i'll let u know.
edit: noway, same behavior, well.. I then try to reinstall DME..let's see..

This AVC/H.264 track's timing information indicates that it uses a variable frame rate. However, no default duration nor an external timestamp file has been provided for it, nor does the source container provide timestamps. The resulting timestamps may not be useful.

General
Complete name               : C:\\audio\AC3\_ - 3 - DTS Master Audio, English, 5.1 channels, 24 bits, 48kHz.dtsma_640k.ac3
Format                      : AC-3
Format/Info                 : Audio Coding 3
Commercial name             : Dolby Digital
File size                   : 574 MiB
Duration                    : 2 h 4 min
Overall bit rate mode       : Constant
Overall bit rate            : 644 kb/s

Audio
Format                      : AC-3
Format/Info                 : Audio Coding 3
Commercial name             : Dolby Digital
Duration                    : 2 h 4 min
Bit rate mode               : Constant
Bit rate                    : 640 kb/s
Channel(s)                  : 6 channels
Channel layout              : L R C LFE Ls Rs
Sampling rate               : 48.0 kHz
Frame rate                  : 31.250 FPS (1536 SPF)
Compression mode            : Lossy
Time code of first frame    : 00:00:00:00
Time code source            : Stream
Stream size                 : 574 MiB (100%)
Service kind                : Complete Main
Time code of first frame    : 00:00:00:00 (23.976 fps), embedded in stream

the DDP created with same software, DME, using the same sources mono wavs, works normally, recognized and muxed..
here mediainfo

General
Complete name               : C:\audio\DDP\_ - 3 - DTS Master Audio, English, 5.1 channels, 24 bits, 48kHz.dtsma_768k.ec3
Format                      : E-AC-3
Format/Info                 : Enhanced AC-3
Commercial name             : Dolby Digital Plus
File size                   : 685 MiB
Duration                    : 2 h 4 min
Overall bit rate mode       : Constant
Overall bit rate            : 768 kb/s

Audio
Format                      : E-AC-3
Format/Info                 : Enhanced AC-3
Commercial name             : Dolby Digital Plus
Duration                    : 2 h 4 min
Bit rate mode               : Constant
Bit rate                    : 768 kb/s
Channel(s)                  : 6 channels
Channel layout              : L R C LFE Ls Rs
Sampling rate               : 48.0 kHz
Frame rate                  : 31.250 FPS (1536 SPF)
Compression mode            : Lossy
Stream size                 : 685 MiB (100%)
Service kind                : Complete Main

[maudit]

noway, tried to downgrade toolnix, the same.
tried to reinstall DME and re-create the AC3, same.. recognized as a video..
I don't know what's going on, I started using AC3 from DME only recently, but I'm sure I had no similar problems with my firsts mux.
with DDP no problems at all..

idk, trying to figure out what's the problem, meanwhile I move forward using the AC3 created with useac3to.

[Ennio]

What stands out to me is MediaInfo text saying "Time code of first frame : 00:00:00:00 (23.976 fps), embedded in stream". I've never seen such MediaInfo data for audio.

For synching purposes, DTS(-HD) carries video framerate timecodes in its metadata. Not sure, but given "PAL" in the name, I can imagine that this dts stream was created for 23.976 fps video, not been touched since and was muxed with 25fps video.
Maybe you accidentally used the dts track (or the entire mediafile) as source to the AC3 encodes, instead of the decompressed wavs? Where during recode DME maybe reads and writes back native video framerate timestamps, in such a way that MKVToolNix parser is confused and mistakes it for video.

[maudit]

yes, that line is weird.
I still have to understand where my error is.
yes PAL is a tag I've added to remember me that the audio is for the 25p video.
I used eac3to to create mono wavs, with -changeto25.000 parameter, then I used them into DME.
anyway.. I now I'm doing another movie and I have to take its .thd in order to create both DD and DDP,
this time without touching the lenght, let's see if I have the same problem...
more info soon...

[maudit]

noway, same thing, recognized as a video.
same mediainfo line Time code of first frame : 00:00:00:00 (23.976 fps), embedded in stream
can't really get what i am doing wrong. DDP is ok, why not DD?

DME default settings
https://www.dropbox.com/s/dawarz9gavvfwii/Screenshot%202022-11-17%2015.19.08.png?dl=0

TOOLNIX
https://www.dropbox.com/s/j8o5se7berm6tsa/Screenshot%202022-11-17%2015.21.25.png?dl=0

USEAC3TO LOG
https://www.dropbox.com/s/0edluaa41vj061b/Blue%20Thunder%20%281983%29_track2_%5Beng%5D...Job_1.log?dl=0

General
Complete name               : C:\Users\antip\Desktop\Tuono Blu (Badham, 1983)\.source\audio\AC3\Blue Thunder (1983)_track2_[eng]_DELAY 0ms.thd_640k.ac3
Format                      : AC-3
Format/Info                 : Audio Coding 3
Commercial name             : Dolby Digital
File size                   : 503 MiB
Duration                    : 1 h 49 min
Overall bit rate mode       : Constant
Overall bit rate            : 644 kb/s

Audio
Format                      : AC-3
Format/Info                 : Audio Coding 3
Commercial name             : Dolby Digital
Duration                    : 1 h 49 min
Bit rate mode               : Constant
Bit rate                    : 640 kb/s
Channel(s)                  : 6 channels
Channel layout              : L R C LFE Ls Rs
Sampling rate               : 48.0 kHz
Frame rate                  : 31.250 FPS (1536 SPF)
Compression mode            : Lossy
Time code of first frame    : 00:00:00:00
Time code source            : Stream
Stream size                 : 503 MiB (100%)
Service kind                : Complete Main
Time code of first frame    : 00:00:00:00 (23.976 fps), embedded in stream

[Ennio]

I don't know DME. Seems professional software. Looking at it for the first time and trying to understand. I am curious about what possible options the "Embedded timecode" mode dropdown box would offer. First jump to mind as to why DDP encode causes no issues would be because you've set another mode for it. Which is not visible now.

[Luke M]

You talking about this?

https://en.wikipedia.org/wiki/Disc_Description_Protocol

Oh wait...is "DDP" Dolby Digital Plus? Usually people write DD+.

[ProWo]

DME default settings
https://www.dropbox.com/s/dawarz9gavvfwii/Screenshot%202022-11-17%2015.19.08.png?dl=0

Whats about Content Type? You have selected General.
What other options are available here?

[maudit]

I am curious about what possible options the "Embedded timecode" mode dropdown box would offer. First jump to mind as to why DDP encode causes no issues would be because you've set another mode for it. Which is not visible now.

https://www.dropbox.com/s/c9w7ostwrgvydgo/embedded%20timecode.png?dl=0

Oh wait...is "DDP" Dolby Digital Plus? Usually people write DD+.

I think DDP is the most used, at least in filenames.

Whats about Content Type? You have selected General.
What other options are available here?

it's MUSIC.
https://www.dropbox.com/s/ow5i6c9lkfrafn5/content%20type.png?dl=0



what is weird to me is that I always used default settings and if I remember well(but maybe not),
I had no problems of this kind, the first times I used it.
anyway I now try to redo the DD using EMBEDDED TIMECODE MODE OFF...
I'll let u know....

edit2:
I still have to check if the sync is good but apparently it works, when using MODE OFF. (edit: confirmed: it works)
https://www.dropbox.com/s/p3g3bcgnyumg2pl/it%20works.png?dl=0
The "new" file also is 500MB, the exact size of the DD created with useaceto,
instead of the previous one of 503MB, so thx for the hint @Ennio, I try this way now.



anyway this "pro" software is available if u search for it, and if you want to try yourself.
but most of the people I know prefer to use DDE(cli), which they say is better, instead of DME, but it's not for me,
I prefer GUI over a CLI software.

[Ennio]

Nice it works. It was a suggestion from the hip. It would raise a question as to why MKVToolNix doesn't throw an error when importing an AC3 track from blu-ray. Assuming it would still hold the framerate timestamps.

It has a certain degree of education, having this peek in Dolby encoding GUI. If I understand things right, the "Embedded timecode" option should be there for "Dolby Digital Plus for Blu-ray". Also because it carries an AC3 core. Could you do me a favour and post a screenshot of the settings for that format too? Preferably with the embedded timecode mode box dropped down, so that it shows all options. Thanks in advance.

[maudit]

Could you do me a favour and post a screenshot of the settings for that format too? Preferably with the embedded timecode mode box dropped down, so that it shows all options. Thanks in advance.

sure.
I never used this, I don't know anything about that file format .eb3

https://www.dropbox.com/s/f18p3etzcihzwp8/for%20bluray.png?dl=0

[Ennio]

Thank you for the screenshot.

I wouldn't worry too much about what extensions DME uses for the several outputs. For example .eb3, I think the characters e and b are just used to denote which codec for which purpose, and wouldn't point to a difference in binaries.
As I said, "Dolby Digital Plus for Blu-ray" carries an AC3 core and additional E-AC3 data. The core provides with backward compatibility. It's mandatory for blu-ray. When this kind of bitstream is offered to an (older) AVR/decoder that can't handle E-AC3, the AC3 core still can be decoded, and the extra E-AC3 data is simply ignored.
This buildup is different from that of "Dolby Digital Plus for online media". It's used by streaming services like Netflix. Here the full bitstream is E-AC3 only. No core. Obviously an E-AC3 decoder is required here.