Bad video files
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James McConkey
Nov 7, 2016, 2:21:43 PM11/7/16
to QLab
Greetings,
I have been using QLab for about 2 years now with many dozens of video files playing perfectly. Only recently (since May) I have run into several files that will not play properly on pretty much all Macs that I use (MBP, iMac, older Mac Pro).
The files all play fine on Quicktime
When played on QLab-the audio is fine but the video either freezes soon after starting or stutters terribly with 2-5 second lags.
I get all video files from outside sources, numerous creators, computers, software.
All my computers are running the latest version of QLab and 10.10.5 or 10.11.5
Problems with both .mov and .mp4
All are H.264 ( I can only tell from VLC and Get Info)
I am trying to analyze why these files are different in order to avoid problems in the future. Granted I am not running the finest hardware but I have not had a problem until recently. The only difference I can tell with some of the bad files is that they are 59.94 frame rate but I do have at least one that is 29.97.
Is there something that I am not seeing? I am vaguely familiar with Pro Res types and how some are more intensive but I cannot see that any of these files are defined as Pro Res.
Thoughts?
I have been using QLab for about 2 years now with many dozens of video files playing perfectly. Only recently (since May) I have run into several files that will not play properly on pretty much all Macs that I use (MBP, iMac, older Mac Pro).
The files all play fine on Quicktime
When played on QLab-the audio is fine but the video either freezes soon after starting or stutters terribly with 2-5 second lags.
I get all video files from outside sources, numerous creators, computers, software.
All my computers are running the latest version of QLab and 10.10.5 or 10.11.5
Problems with both .mov and .mp4
All are H.264 ( I can only tell from VLC and Get Info)
I am trying to analyze why these files are different in order to avoid problems in the future. Granted I am not running the finest hardware but I have not had a problem until recently. The only difference I can tell with some of the bad files is that they are 59.94 frame rate but I do have at least one that is 29.97.
Is there something that I am not seeing? I am vaguely familiar with Pro Res types and how some are more intensive but I cannot see that any of these files are defined as Pro Res.
Thoughts?
micpool
Nov 7, 2016, 3:02:35 PM11/7/16
to QLab
The trouble with h264 is that there are tons of different encoding options that will produce a valid h264 file. Some of these will work well, and some will produce files QLab can barely play.
One of the advantages of the ProRes codecs is that you can't really mess up the encoding. Just pick the flavour of ProRes you want depending on your balance between quality and number of simultaneous videos
The first codec to try when encoding files for Qlab is ProRes 422 (proxy) which gives good video quality on projector output under most circumstances.
If you require higher picture quality then use ProRes 422 (LT) but be aware this may halve the number of simultaneous videos Qlab can handle.
If you need transparency use ProRes 444 but be aware the data rate for this codec is extremely high.
Mic
James McConkey
Nov 7, 2016, 4:48:17 PM11/7/16
to QLab
Thank you Mic,
I can try to ask the myriad video creators to deliver files with those specific codecs but my guess is they are using cheap software other than Final Cut.
It sounds like I may just have to to test every video ahead of time to see if it will work.
micpool
I can try to ask the myriad video creators to deliver files with those specific codecs but my guess is they are using cheap software other than Final Cut.
It sounds like I may just have to to test every video ahead of time to see if it will work.
micpool
| 12:02 PM (1 hour ago) |
The
trouble with h264 is that there are tons of different encoding options
that will produce a valid h264 file. Some of these will work well, and
some will produce files QLab can barely play.
One
of the advantages of the ProRes codecs is that you can't really mess up
the encoding. Just pick the flavour of ProRes you want depending on
your balance between quality and number of simultaneous videos
The
first codec to try when encoding files for Qlab is ProRes 422 (proxy)
which gives good video quality on projector output under most
circumstances.
If you require higher picture quality then use
ProRes 422 (LT) but be aware this may halve the number of simultaneous
videos Qlab can handle.
If you need transparency use ProRes 444 but be aware the data rate for this codec is extremely high.
Mic
Joshua Langman
Nov 7, 2016, 5:30:19 PM11/7/16
to QLab
James,
Get Compressor and batch-convert them all yourself.
It'll be the best $50 you ever spent.
Josh
Joshua Langman
Nov 7, 2016, 5:31:27 PM11/7/16
to QLab
Sorry, I meant to include a link, in case is wasn't clear what I was talking about: http://www.apple.com/final-cut-pro/compressor/
On Monday, November 7, 2016 at 2:21:43 PM UTC-5, James McConkey wrote:
Greg Leeper
Nov 8, 2016, 12:57:18 PM11/8/16
to QLab
Good to know Mic, thanks!
I've also felt like video playback is not working as well as it used to. Most of my files come from clients and are H.264. I sent a problematic workspace into Figure53 and Sam let me know that some of the files had encoding errors that were causing problems. He too suggested re-encoding them which has helped.
Almost all these client files are being delivered as an online download - recently a workspace with two SD surfaces on one 1920 HD output running a single H.264 file on each surface, would loop once then stall on a frame in the middle.. the active cues display said it was running and moving forward but the output was locked up on only one of the surfaces. A quick export to ProRes422 fixed it.
RE: Stuttering playback - I've had problems on multiple machines all running 10.10 or 10.11 and current builds of Qlab play and loop a file fine in rehearsals, and then during show time I get the stuttering. I often have a still running in the background and have found even ONE STILL can cause the stuttering - in that clicking off that layer while the video is running fixes the stuttering right away.
I find it hard to believe Qlab and my 2015 Retina 15" MBPRO can't handle one HD still and one HD video clip at the same time so it feels something else is going on here. Most recently it happened with a 1920x1080 Prores422 file that played fine alone, but with a still tiff file running in the background it was dropping frames. Audio was fine, video was chugging.
(it was a larger than HD still being scaled down... but really? )
I've built much more intense workspaces in the past w/o issues like this.
It also feels like there is something cumulative going on that a restart of Qlab, and sometimes a restart of the laptop, seem to fix it (at least temporarily until it starts to chug again... ugh.)
It has been happening to us on every show this year at one time or another.
James McConkey
Nov 10, 2016, 5:15:20 PM11/10/16
to QLab
A follow up...
My issues were resolved by converting the files to ProRes 422. One was done by a colleague in Compressor and another in iMovie. The files were significantly larger but that is not a large problem in my situation.
iMovie 10 and beyond have the option to encode in ProRes 422 so I already had the software and most of those in the community use iMovie they just need to know the proper settings.
Thanks to all for the help.
My issues were resolved by converting the files to ProRes 422. One was done by a colleague in Compressor and another in iMovie. The files were significantly larger but that is not a large problem in my situation.
iMovie 10 and beyond have the option to encode in ProRes 422 so I already had the software and most of those in the community use iMovie they just need to know the proper settings.
Thanks to all for the help.
On Monday, November 7, 2016 at 11:21:43 AM UTC-8, James McConkey wrote:
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