MediaInfo / Bugs / #839 Wrong channels layout shown for DTS-HD 5.1

Jerome Martinez - 2014-03-19

I think we don't talk of the same thing: I don't see the Mediainfo line with indication of the channel layout (the order inside the stream). The only info I see is "Front: L C R, Side: L R, LFE" with is an indication of channel positions in the room, ordered by layers (Front, Side, Rear, LFE) then from Left to right (so you could have also "L CL C CR R" for 5 front channels whatever is the layout in the stream), without any information about how it is coded inside the stream. So with "L R C LFE SL SR" from you, MediaInfo output is correct (for the purpose of this field "Front: L C R, Side: L R, LFE", all 6 channels are there).

I think that you can have the piece of data you are looking for: in newest versions, there is a "ChannelLayout" line (hidden by default):

Channel positions : Front: L C R, Side: L R, LFE Channel positions : 3/2/0.1 ChannelLayout : C L R Ls Rs LFE

FYI, I don't see "L R C LFE SL SR" in DTS specs:
AMODE CHS Arrangement
0b000000 1 A
0b000001 2 A + B (dual mono)
0b000010 2 L + R (stereo)
0b000011 2 (L+R) + (L-R) (sum-difference)
0b000100 2 LT +RT (left and right total)
0b000101 3 C + L + R
0b000110 3 L + R+ S
0b000111 4 C + L + R+ S
0b001000 4 L + R+ SL+SR
0b001001 5 C + L + R+ SL+SR
0b001010 6 CL + CR + L + R + SL + SR
0b001011 6 C + L + R+ LR + RR + OV
0b001100 6 CF+ CR+LF+ RF+LR + RR
0b001101 7 CL + C + CR + L + R + SL + SR
0b001110 8 CL + CR + L + R + SL1 + SL2+ SR1 + SR2
0b001111 8 CL + C+ CR + L + R + SL + S+ SR

I have doubts about LFE (the spec is not obvious, if you can help I would appreciate), but "L R C" is not there (it begins with "C").

Please test with 0.7.67, then we can see how we disagree based on the right MediaInfo line.
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:

Jerome Martinez - 2014-03-19

status: open --> pending-works-for-me

assigned_to: Jerome Martinez

Priority: 9 --> 3
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:

Albert25 - 2014-03-27

Please consider making "ChannelLayout" the default instead of "Channel Positions". Or alternatively, display both.

The current display is extremely confusing, because "L C R L R LFE" happens to be valid standard layout, which was widely used in the film industry. DCPs now use the SMPTE layout.

I thought my export settings were wrong, checked them, re-exported, until I finally came across this bug-report.

Anyway, thanks a lot for a great tool!

If you would like to refer to this comment somewhere else in this project, copy and paste the following link:

Jerome Martinez - 2014-03-28

"L C R L R LFE" happens to be valid standard layout,

I display on purpose a "non classic" character string, in order not to mix it with channel layout.

Or alternatively, display both.

If I listen to everybody, the default output would be the "advanced" display, with all fields, I must do choices and I am aware it is not the right one for everybody.

The current display is extremely confusing

Any proposal for the field name in order not to be confusing?
The goal is to display channel position by layers (Front, Side, Back, TopFront TopBack... It will be even more complex with 22.2 config), not the order in the stream.

If you would like to refer to this comment somewhere else in this project, copy and paste the following link:

First of all, thank you for clearing my confusion around 'Channel position' property. Nevertheless, here's a bit more details on the matter.

$ ffmpeg -i 00005.m2ts
Input #0, mpegts, from 00005.m2ts:
  Duration: 01:36:27.15, start: 600.000000, bitrate: 23663 kb/s
  Program 1 
    Stream #0:0[0x1011]: Video: h264 (High) (HDMV / 0x564D4448), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 23.98 fps, 23.98 tbr, 90k tbn, 47.95 tbc
    Stream #0:1[0x1100]: Audio: dts (DTS-HD MA) ([134][0][0][0] / 0x0086), 48000 Hz, 5.1(side), fltp, 1536 kb/s
    Stream #0:2[0x1200]: Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090)

As you can see see here, ffmpeg detects 5.1(side) channel layout, which is:

$ ffmpeg -layouts | grep -F '5.1(side)'
5.1(side)   FL+FR+FC+LFE+SL+SR

However, mediainfo v0.7.67 shows:

ChannelLayout                            : C L R Ls Rs LFE

ffmpeg was able to properly downmix that stream to stereo. I'll get back to you on this after demuxing and checking the individual channels.

Jerome Martinez - 2014-04-16

I may be wrong, but I don't see such config in DTS specs.
For 5 channels (without LFE), I see only:
"5 C + L + R+ SL+SR"
I rely on ETSI TS 102 114 V1.3.1 (2011-08) Table 5-4: Audio channel arrangement (AMODE).

For the LFE channel, I have more doubts, because the specs is not obvious (at least for me).
I am not an expert of DTS, I don't decode it (I only parse the header), so I definitely may be wrong, but I want to know how I am wrong before I change something.
Are you sure the "FL+FR+FC+LFE+SL+SR" is the arrangement in the file and not only the output from FFmpeg?

If you would like to refer to this comment somewhere else in this project, copy and paste the following link:

Sergey Kolchin - 2014-04-16

Demuxed the channels with ffmpeg. The layout is definitely FL FR C LFE SL SR, although I'm not absolutely sure it is the actual channels layout and not some internal ffmpeg mangling involved. The release in question is Ku! Kin-dza-dza Blu-ray. I can share with you a piece of the stream, but feel free to close the bug if you think it's not important.

Last edit: Sergey Kolchin 2014-04-16

If you would like to refer to this comment somewhere else in this project, copy and paste the following link:

Jerome Martinez - 2014-04-16

There is no plan to provide the same output as FFmpeg (my goal is not to replace FFmpeg)
The plan is to output the real order inside the stream, so I need to know if this order is the order inside the stream, for sure (with explanations compared to the spec)

If you would like to refer to this comment somewhere else in this project, copy and paste the following link:

Sergey Kolchin - 2014-04-16

Here's a piece of the stream: .DTS, 16 Mb.

If you would like to refer to this comment somewhere else in this project, copy and paste the following link:

Jerome Martinez - 2014-04-16

As said, there is only one config in the spec for a 5 channel stream.
So your file has the same config as all other 5 channel files.
I need to be convinced I read wrongly the specs and I need to get the right order for all AMODE configs.
Providing the FFmpeg output is not enough, I don't know if this output is the order from FFmpeg output or inside the file.
convince me that the order in the file is not the one I provide, based on specs and/or some external documentation.

If you would like to refer to this comment somewhere else in this project, copy and paste the following link:

Sergey Kolchin - 2014-04-16

I suppose ffmpeg mangles the layout internally, and the actual layout is C L R SL SR with AMODE being 0b001001. Filling this bug report was a mistake, sorry for wasting your time.

If you would like to refer to this comment somewhere else in this project, copy and paste the following link:

Jerome Martinez - 2014-04-16

No problem, it is better to be sure we are in sync.
Sometimes, I am wrong and I correct it.
If you find something about channel order which is wrong in MediaInfo, reopen the ticket.

If you would like to refer to this comment somewhere else in this project, copy and paste the following link:

Jerome Martinez - 2014-04-16

status: pending-works-for-me --> closed-works-for-me
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:

Wrong channels layout shown for DTS-HD 5.1

A unified display of relevant technical and tag data for A/V files

Group

Searches

Help

#839 Wrong channels layout shown for DTS-HD 5.1

Discussion