Prores deliveries not making me happy – Glitches

[Charlie Austin]

Have you bugged Apple about it? If it’s a real, reproducible (or widespread) issue they’d likely be interested…

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~ My FCPX Babbling blog ~
~”It is a poor craftsman who blames his tools.”~
~”The function you just attempted is not yet implemented”~

[Frank Gothmann]

Will do, but want to see if anyone may have more info about it as it could be pretty much anything: Prores, Quicktime on Mac itself, OSX, filesystem implementation, drivers.
If remember reading about similar glitches with Prores here on the Cow a while back but search didn’t get me any further and I cannot find the posts.

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[Charlie Austin]

[Frank Gothmann] “but want to see if anyone may have more info about it as it could be pretty much anything”

I’ll keep an eye out, as most of the sources we get are prores as well. I have seen glitches on sources, but don’t recall it being widespread. If I get some time maybe I’ll go back and take a look at a few…

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~ My FCPX Babbling blog ~
~”It is a poor craftsman who blames his tools.”~
~”The function you just attempted is not yet implemented”~

[Frank Gothmann]

Widespread is relative. 30hrs of content isn’t something a lot of people are moving all the time I assume, especially when they are editing with various source formats, so 1 glitch per 30 hrs is something one may consider an unlucky event.
We are not editing so much but encoding, transcoding at lot of stuff every month so our turnover in material is a lot more so it’s easier to see a problematic pattern, especially since it’s coming from so many different suppliers and has passed QC at an earlier stage.

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“You also agree that you will not use these products for… the development, design, manufacture or production of nuclear, missiles, or chemical or biological weapons.”
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[Walter Soyka]

I’m curious if the decoder matters. Does ffmpeg see the same glitching as QuickTime does?

Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
RenderBreak Blog – What I’m thinking when my workstation’s thinking
Creative Cow Forum Host: Live & Stage Events

[Frank Gothmann]

Yes, also present when viewed with Mplayer or Videolan. It’s always 2-3 frames.
Here is a screenshot of the most recent example we ran into this morning (It’s a screenshot because exporting just that frame gives just green, nothing else).

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“You also agree that you will not use these products for… the development, design, manufacture or production of nuclear, missiles, or chemical or biological weapons.”
iTunes End User Licence Agreement

[Keith Koby]

Haven’t seen anything here, but we are using xsan. We receive a lot of prores from studios and the various hollywood labs. Every output file gets visually QC’d and we haven’t caught that. (Output vod files with a glitch would prompt us to go back and check the mezz.)

[Herb Sevush]

I’ve seen that when encoding half hour shows in ProRes 422 for broadcast. Not often, not recently, but I’ve seen it and assumed it was a computer hiccup on my end during encoding. Major PITA, having to re-encode whole show, made me yearn for tape where I could fix with a simple insert edit.

Herb Sevush
Zebra Productions
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nothin’ attached to nothin’
“Deciding the spine is the process of editing” F. Bieberkopf

[Keith Koby]

By the way – I saw something like this a few years back on our old xsan storage where it was one particular drive that was failing but not reporting itself as failing so it would just write a few bad Bytes(?) of data that would give us weird looking artifacts on the prores files. The funny thing is, the problem would only exhibit itself on ProRes HD files. Not on ProRes SD or even on DVCPRO HD or anything else. It was like the chunk of data being delivered to the one particular drive on that raid was just big enough with ProRes HD to trigger the symptom. We wouldn’t see it with smaller data rates written to the same storage. Some of the artifacts look similar to what you are seeing, but we would not get those big green hits. That is definitely more severe than what we saw.

[Frank Gothmann]

Up till now we thought it was a dropout related to failing error correction on HDCAM-SR decks, bad cabeling, disks etc. but it’s just weird that it’s always Prores QT, always during the first two or three minutes, never in the middle or the end, and that it’s with all big labs happening time and time again under the same conditions.

[Keith Koby] “By the way – I saw something like this a few years back on our old xsan storage where it was one particular drive that was failing but not reporting itself as failing so it would just write a few bad Bytes(?) of data that would give us weird looking artifacts on the prores files. The funny thing is, the problem would only exhibit itself on ProRes HD files. Not on ProRes SD or even on DVCPRO HD or anything else. It was like the chunk of data being delivered to the one particular drive on that raid was just big enough with ProRes HD to trigger the symptom. We wouldn’t see it with smaller data rates written to the same storage. Some of the artifacts look similar to what you are seeing, but we would not get those big green hits. That is definitely more severe than what we saw.”

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“You also agree that you will not use these products for… the development, design, manufacture or production of nuclear, missiles, or chemical or biological weapons.”
iTunes End User Licence Agreement