Friday, June 5, 2015

Re: [Avid-L2] QC Issue with Interleave vs. discrete audio as I anticipated?

 

in my experience, it's best to stick with the specs. To a t. Maximizes your odds of passing QC.

You have to realize that with huge number of files to check, QC is done in 2 stages:
-a preliminary, automated pass, which detects formatting, syntax, packaging errors(like yours)
there will be no human intervention to decide if the errors are benign, source will simply fail based on alarm settings
-a second, manual pass, where they check for more subtle errors, hard to catch by machines. They get pretty good at it, but there will be a certain level of subjectivity there.

The fact that they can play/watch the content is immaterial to the qualification process. We don't know what their workflows and processing steps are for the file ingest/transcode.

cheers,
BG

From: "bigfish@pacbell.net [Avid-L2]" <Avid-L2@yahoogroups.com>
To: Avid-L2@yahoogroups.com
Sent: Friday, June 5, 2015 10:10 PM
Subject: Re: [Avid-L2] QC Issue with Interleave vs. discrete audio as I anticipated?

 
On the delivery Specs it says:

One mono audio stream per channel"

I'm not saying they are wrong given that spec but what I'm trying to understand is what the problem is with the interleaved track of 12 if it as they say, "plays fine into the Amberfin system."  It looks like I've found my workflow to deliver what they want but it's an extra step that just seems unnecessary in reality.  If the file didn't play for them that's an issue but it did so why do they care about this.  What problem does this really create for them?  If the only answer is we want it to conform just because, well I will live with that but I'd like to take the opportunity to understand better what the downside of the interleaved audio is.


---In avid-l2@yahoogroups.com, <bogdan_grigorescu@...> wrote :

can you provide the delivery spec for audio?

cheers,
BG


From: "John Moore bigfish@... [Avid-L2]" <Avid-L2@yahoogroups.com>
To: Avid L2 <avid-l2@yahoogroups.com>
Sent: Friday, June 5, 2015 9:47 PM
Subject: [Avid-L2] QC Issue with Interleave vs. discrete audio as I anticipated?

 
 A few weeks back I mentioned that I was expecting to run into the Interleaved audio from QT Pro ProResHQ exports problem on a file delivery.  Well my dreams came true today.  Even though the QC note was audio and video played fine into their Amberfin system because the MediaInfo showed on audio track with 12 channels in it that was a problem.  Here are the exact comments:

FILE
-ProRes 422 (HQ) 1080p 23.98sf NDF
-One audio stream with 12 audio channels (needs to be 12 audio streams with one channel per stream), 48 kHz, 24 bit, PCM – see attached MediaInfo form
-File plays down in AmberFin without issue

I was also sent the mediainfo document from our test file and another one from an acceptable file:

Our Problem file show audio as:

Audio
ID                                       : 1
Format                                   : PCM
Format settings, Endianness              : Little
Format settings, Sign                    : Signed
Codec ID                                 : lpcm
Duration                                 : 45mn 27s
Bit rate mode                            : Constant
Bit rate                                 : 13.8 Mbps
Channel(s)                               : 12 channels
Channel positions                        : L R Discrete-2 Discrete-3 Discrete-4 Discrete-5 Discrete-6 Discrete-7 Discrete-8 Discrete-9 Discrete-10 Discrete-11
Sampling rate                            : 48.0 KHz
Bit depth                                : 24 bits
Stream size                              : 4.39 GiB (8%)
Language                                 : English
Encoded date                             : UTC 2015-05-26 22:24:51
Tagged date                              : UTC 2015-05-26 22:59:38

The Acceptable file shows:

Audio #1
ID                                       : 16
Format                                   : PCM
Format settings, Endianness              : Little
Format settings, Sign                    : Unsigned
Codec ID                                 : in24
Duration                                 : 21mn 31s
Source duration                          : 21mn 32s
Bit rate mode                            : Constant
Bit rate                                 : 1 152 Kbps
Channel(s)                               : 1 channel
Channel positions                        : Front: C
Sampling rate                            : 48.0 KHz
Bit depth                                : 24 bits
Delay relative to video                  : 127ms
Stream size                              : 177 MiB (1%)
Source stream size                       : 177 MiB (1%)
Language                                 : English
Encoded date                             : UTC 2015-05-15 22:30:10
Tagged date                              : UTC 2015-05-15 22:30:10

Audio #2
ID                                       : 17
Format                                   : PCM
Format settings, Endianness              : Little
Format settings, Sign                    : Unsigned
Codec ID                                 : in24
Duration                                 : 21mn 31s
Source duration                          : 21mn 32s
Bit rate mode                            : Constant
Bit rate                                 : 1 152 Kbps
Channel(s)                               : 1 channel
Channel positions                        : Front: C
Sampling rate                            : 48.0 KHz
Bit depth                                : 24 bits
Delay relative to video                  : 127ms
Stream size                              : 177 MiB (1%)
Source stream size                       : 177 MiB (1%)
Language                                 : English
Encoded date                             : UTC 2015-05-15 22:30:10
Tagged date                              : UTC 2015-05-15 22:30:10

etc.... through all 12 channels


Now I note the difference but it is only in this print out and how the metadata is layed out.  According to their own comments the file played fine into Amberfin and they were able to access and QC all tracks.  So what is the Fing problem here.  I will redo with 12 mono tracks and I believe that will work but given it's only in the mediainfo report that the difference is noted it really seems like a non issue to me.  If they told me because of the interleaved audio tracks they could not ingest the file that would be different.  What am I missing here?  I really feel like I'm dealing with a cashier at McDonald's who tells me "I don't have a button for that."  Someone please inform me of what problem there is when the file plays fine into Amberfin?  Also I noted that all the Channel Position data for the "acceptable file say 'Front C'' and not their correct positions or track assignments so clearly this metadata isn't clogging the system.
 
John Moore
Barking Trout Productions
Studio City, CA
bigfish@...




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