Opened 6 years ago

Last modified 5 months ago

#3595 open enhancement

Support >6 channels in E-AC-3 audio encoder

Reported by: 11rcombs Owned by:
Priority: wish Component: avcodec
Version: git-master Keywords: eac3
Cc: LigH, rodger.combs@gmail.com, j.kis@me.com, hoffbrinkle@hotmail.com, Nomis101@web.de Blocked By:
Blocking: Reproduced by developer: yes
Analyzed by developer: no

Description

E-AC-3 supports up to 15 full-bandwidth channels, but libavcodec's encoder currently doesn't support 6.1 and 7.1 channel layouts. Do these layouts just need to be added to ff_ac3_channel_layouts, or would this require additional work on the encoder?

Attachments (5)

snip.eac3 (500.0 KB) - added by LigH 4 years ago.
7.1 channel Blu-ray E-AC-3 with 5.1 AC-3 core and 2 dependent substreams
7.1sample1.dts (666.1 KB) - added by ackbc 6 months ago.
7.1sample2.thd (400.3 KB) - added by ackbc 6 months ago.
7.1sample3.eac3 (282.0 KB) - added by ackbc 6 months ago.
7.1sample3.mka (287.8 KB) - added by ackbc 6 months ago.

Change History (27)

comment:1 Changed 6 years ago by cehoyos

  • Priority changed from minor to wish
  • Reproduced by developer set
  • Status changed from new to open
  • Summary changed from Support >5 channels in E-AC-3 audio to Support >6 channels in E-AC-3 audio

comment:2 follow-up: Changed 4 years ago by LigH

This does not only belong to the E-AC-3 encoder, but also to the decoder or the format recognition in general. There is a report in the German doom9/Gleitz video forum that ffmpeg does not even recognize a 7.1 channel Blu-ray audio stream correctly, which consists of a 5.1 AC-3 core and additional E-AC-3 channels. It may have been related to a slightly older version; a rather current ffmpeg version (N-81308-g369ed11, 2016-08-09) prints a warning that it will handle only the 5.1 core:

[eac3 @ 0000000002a8f900] Dependent substream decoding is not implemented. Update your FFmpeg version to the newest one from Git. If the problem still occurs, it means that your file has a feature which has not been implemented.
[eac3 @ 0000000002a8f900] If you want to help, upload a sample of this file to ftp://upload.ffmpeg.org/incoming/ and contact the ffmpeg-devel mailing list. (ffmpeg-devel@ffmpeg.org)

Possibly relevant: MediaInfo? does not recognize it correctly either (e.g. reports an obviously improbable bitrate of 500 bytes per second).

Changed 4 years ago by LigH

7.1 channel Blu-ray E-AC-3 with 5.1 AC-3 core and 2 dependent substreams

comment:3 Changed 4 years ago by cehoyos

  • Cc LigH added

Is this the one sample we know about (from a demo disk) or a new file?

comment:4 Changed 4 years ago by LigH

AFAIK it's a new file, extracted from a Blu-ray by a Gleitz forum member.

http://forum.gleitz.info/showthread.php?47670-e-ac3-richtig-convertieren

comment:5 Changed 4 years ago by cehoyos

Then please ask for a longer sample that provides actual audible sound (at least 2,5M) and ask which Bluray this is.

Last edited 4 years ago by cehoyos (previous) (diff)

comment:6 Changed 4 years ago by cehoyos

Two minute eac3 7.1 sample (that does not come from the demo disk) uploaded to http://samples.ffmpeg.org/ffmpeg-bugs/trac/ticket3595/

comment:7 in reply to: ↑ 2 Changed 4 years ago by dcxero

Replying to LigH:

Possibly relevant: MediaInfo? does not recognize it correctly either (e.g. reports an obviously improbable bitrate of 500 bytes per second).

MediaInfo? only seems to have a bug reading 7.1 Dolby Digital Plus tracks authored using the Blu-ray Disc profile (which is what the other samples use). It can read 7.1 Dolby Digital Plus tracks authored using the standard profile (which is used more for software and file/streaming distribution)

Here is a Standard profile 7.1 sample: https://www.datafilehost.com/d/ae18d85c

Last edited 4 years ago by dcxero (previous) (diff)

comment:8 Changed 2 years ago by richardpl

  • Summary changed from Support >6 channels in E-AC-3 audio to Support >6 channels in E-AC-3 audio encoder

comment:9 Changed 2 years ago by johnesz

  • Cc j.kis@me.com added

comment:10 Changed 18 months ago by hoffer

  • Cc hoffbrinkle@hotmail.com added

comment:11 Changed 6 months ago by ackbc

  • Reproduced by developer unset

ffmpeg doesn't support encode 7.1 files into 7.1 EAC3

i've uploaded some samples for testing (three 7.1 files), i hope it could support 7.1 EAC3 encode, input output
the closed, dupe ticket https://trac.ffmpeg.org/ticket/8519

update: samples uploaded here.

Last edited 6 months ago by ackbc (previous) (diff)

Changed 6 months ago by ackbc

Changed 6 months ago by ackbc

Changed 6 months ago by ackbc

Changed 6 months ago by ackbc

comment:12 Changed 6 months ago by cehoyos

  • Reproduced by developer set

comment:13 Changed 5 months ago by Nomis101

  • Cc Nomis101@web.de added

This is also an annoying issue for HandBrake?: https://github.com/HandBrake/HandBrake/issues/1085
What makes it so difficult to support >6 channels for E-AC3 encoding?

comment:14 follow-up: Changed 5 months ago by richardpl

Missing actual sponsor.

comment:15 in reply to: ↑ 14 Changed 5 months ago by Nomis101

Replying to richardpl:

Missing actual sponsor.

Thats all? How to find a sponsor? Who can be a sponsor?

comment:16 Changed 5 months ago by richardpl

The one with lot of money.

comment:17 Changed 5 months ago by LigH

They possibly mean: someone willing to pay for access to confidential specifications, level "trade secret, and we have lawyers to protect it".

comment:18 follow-up: Changed 5 months ago by richardpl

Nope, look what I said and please stop spreading false information.

comment:19 in reply to: ↑ 18 Changed 5 months ago by jdlh

Replying to richardpl:

Nope, look what I said and please stop spreading false information.

I'm new to the ticket. @richardpl, I'm afraid your comment:14 is a bit too cryptic for me to understand, especially given how in comment:18 you seem to say that the interpretation in comment:17 is "false information".

Could you please say clearly what you mean by "missing actual sponsor"? What does the sponsor do with their "lot of money"? Who do they give it to? How does it help?

It seems to me that part of what that money would do is pay for access to specifications. But you apparently don't mean that. Maybe it would pay a competent developer to write the necessary code? What do you mean, please?

comment:20 Changed 5 months ago by richardpl

It means to write code. Specification is already available.

comment:21 Changed 5 months ago by LigH

Regarding code, I would call that rather "contributor" than "sponsor". Hence the misunderstanding, maybe... contributing code is hopefully not bound to huge amounts of money. At least I wish.

comment:22 Changed 5 months ago by richardpl

If you want to contribute code and time without any compensation, be my guest.

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