DCP verification player

Anything and everything to do with DCP-o-matic.
Terraform
Posts: 15
Joined: Tue Sep 05, 2017 10:19 pm

Re: DCP verification player

Post by Terraform » Mon Sep 11, 2017 4:28 pm

Hey Carsten,
Well when I listen to it with headphones in easyDCP in some parts the audio sounds distorted a bit.
I went back to D-o-M and looked at the audio waveform graph and it looks like the channel assignment is "correct"..
But am now concerned as to if the distortion is due to channel assignment OR if it is just the way easyDCP handles a stereo mix down of 5.1.

I should point out that I do have some DCP copies of this film that were made for me and the audio does not sound distorted.
I am making this one as I needed a DCP with Spanish subs and wanted to learn how.

The reason I am a bit "unsure" about audio assignment is that the post house that made my master files delivered a 120GB ProRes with 5.1 audio all in one file. As such I don't know how to tell if the tracks are assigned as they should be (which I think is the case) or if maybe something went wrong somewhere.

Here is an screenshot of my audio channel graph:
Image

Carsten
Posts: 1161
Joined: Tue Apr 15, 2014 9:11 pm
Location: Germany

Re: DCP verification player

Post by Carsten » Mon Sep 11, 2017 5:00 pm

The levels appear correct to me, both overall (LUFS) as well as Peak. There is no clipping. If the post house charges money for their work, they should also supply an information sheet with the channel assignments. You could also open the ProRes file in e.g. Quicktime Player and check for the channel number/name reference in the film inspector. Next time, you could also tell the post house to use DCI channel assignments.

It is rather easy to find out the major channels like L/R, center, and LFE, but to tell wether Surround Left or Surround Right are correct is certainly not so easy. You can play the file in DOM, though, and deselect channels in the matrix while playing, so you can identify individual channels as far as possible acoustically. Actually I prefer to have all audio in one file, it actually makes working in DOM easier.

You can also open the audio MXF file that DOM created in Audacity or other audio editors. A 5.1 file will give a very typical waveform pattern with L/R/C/LFE/Ls/Rs from top to bottom.

- Carsten
Last edited by Carsten on Mon Sep 11, 2017 5:16 pm, edited 1 time in total.

Terraform
Posts: 15
Joined: Tue Sep 05, 2017 10:19 pm

Re: DCP verification player

Post by Terraform » Mon Sep 11, 2017 5:16 pm

All good to know for the next film (re: post house and what files to ask for).

QUESTION - am I missing something re: DOM and audio playback? I can't seem to get it to play audio at all in preview... I assumed it just wasn't possible but your last response makes me wonder if I am missing something somewhere? The ability to switch channels on and off while playing would be great for what I want...

Oh and which of the 3 mxf files should I import I just now tried the one that starts with pcm as that made the most sense to me but it came up as gibberish when I imported it to Audacity (as raw data as just brining it in did not work).

Thanks as always for your quick and through response!

Carsten
Posts: 1161
Joined: Tue Apr 15, 2014 9:11 pm
Location: Germany

Re: DCP verification player

Post by Carsten » Mon Sep 11, 2017 11:38 pm

Hi, the current test version does play audio, if enabled in prefs. It can even play to multichannel interfaces e.g. 8ch to HDMI.

The pcm MXF is the right one, but you need to install the ffmpeg 2.2.2 plugin for audacity before it reads MXFs.

http://lame.buanzo.org/#lameosxdl

- Carsten

Cantar4
Posts: 86
Joined: Wed Jul 20, 2016 4:52 pm

Re: DCP verification player

Post by Cantar4 » Tue Sep 12, 2017 2:29 pm

Carsten wrote:
Mon Sep 11, 2017 11:38 pm
... you need to install the ffmpeg 2.2.2 plugin for audacity before it reads MXFs.
What about directly opening this pcm MXF file with VLC ?

notice about the installation of the FFmpeg plugin for Audacity
The former user manual edtion, http://manual.audacityteam.org/man/inst ... _os_x.html
said: Navigate to the folder that contains FFmpeg and select the file "libavcodec.55.dylib".
it now says: select the file "libavformat.55.dylib".
(this worked better for me...)
--jp
--
Attachments
audacity pcm MXF play.jpg
audacity pcm MXF play.jpg (72.18 KiB) Viewed 3010 times
Last edited by Cantar4 on Wed Sep 13, 2017 9:06 pm, edited 5 times in total.

Carsten
Posts: 1161
Joined: Tue Apr 15, 2014 9:11 pm
Location: Germany

Re: DCP verification player

Post by Carsten » Tue Sep 12, 2017 5:23 pm

What about directly opening this pcm MXF file with VLC ?
Because you can't 'see' the audio in VLC, mute/solo individual channels, etc.

- Carsten

Cantar4
Posts: 86
Joined: Wed Jul 20, 2016 4:52 pm

Re: DCP verification player

Post by Cantar4 » Thu Jan 11, 2018 2:26 am

Hi
The latest Dom 2.11.50 DCP to h.264/ProRes converter now totally preserves soft subtitles*.
It becomes possible to verify DCPs at high speed on mp4 players, and frame-by-frame scrutinize a converted film thanks to the bidirectional 1 frame scrub of the IINA and QT players.

A great kudo to Carl for this long sought-after DoM feature !
--
jpb

* Shadows are momentarily replaced by Outlines, which is a non issue for the type of work mp4 files allow.

Bumeaung50
Posts: 1
Joined: Fri Feb 15, 2019 5:30 am

Re: DCP verification player

Post by Bumeaung50 » Fri Feb 15, 2019 8:05 am

Hello! Is latest Dom 2.11.50 DCP to h.264/ProRes converter are able to optimize sound record too? Is this the same work of audacity and had a tutorial like audacity guides? thanks!

Carsten
Posts: 1161
Joined: Tue Apr 15, 2014 9:11 pm
Location: Germany

Re: DCP verification player

Post by Carsten » Fri Feb 15, 2019 4:07 pm

What do you mean with 'optimize sound record'? Also, this thread is old, and DCP-o-matic 2.11.50 is not nearly the latest version now.


- Carsten

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