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Projection to cinema theatre
A local movie theatre is showing my 32 minute video on a cinema screen. However they plan to use a laptop to project the video to the screen. They said to create an mp4 file and that will be sufficient for projection. I created an mp4 file using premiere pro cs6 media encorder. My output variables were: 1920×1080,25fps,progressive VBR, 2 pass target bit rate 14Mbps, Max bitrate 25 and rendered at maximum bit rate. with format h.264. Audio AAC, 320kbps 48 kHz stero.
Naturally these are good settings for you tube and computer and viewing on tv. However I was very surprised that when we tested the video on the cinema screen, the resolution was quite good. There were problems in getting the audio setting settings right and getting the aspect ratio right for the movie screen, but in general the video played pretty well. The VLC media player was first used but there was stuttering on some of the scenes. So we tried Windows media player and that reduced the stuttering.
So what is my question. Given that we are using a computer to project to the screen what are the best settings that will avoid playback problems on the big night. I was told that I should jack up the target bit rate to 50 Mbps to get the best possible playback when the video is screened. I will have a huge file size but I will have the maximum quality and stuttering will be non existent and great colour and picture quality will all be guaranteed. Is this correct and am I at the mercy at the laptops processing power if I increase the file size to that huge level. If I increase to 50Mbps do I need a very fast advanced processor on the laptop to make sure that the video will run smoothly?
Another recommendation is that I should convert the mp4 file to Dcp for projection on the screen and that I need to get the correct settings from the projectionist to do this. This is pretty tricky and as I understand expensive. I would need to have it done professionally. But the key question here is will the viewing and audio quality be that much better than jacking up my bit rate to 50 and would I be able to tell a quality difference ? I hope this all makes sense. Your responses are appreciated.
Kevin Dawson
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6 Replies
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If they can’t run basic H264 files without stuttering/audio/aspect ratio issues then the problem is theirs to fix. This is some insanely basic 101 stuff here.
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Thanks, Kevin,
I too have seen mp4 files and ProRes files projected successfully on a semi-big screen.
It would be helpful to have some spec recommendations. One would think ProRes would look better but dunno.
I understand DCP projections are standard but don’t they require special hard drive packages for theater systems? Can one run a DCP from a laptop? That would be interesting. My question always with cheap DCP conversions is how do you QC them without a projector?
Best wishes for your shows,
RobertRobert Withers
Independent/personal/avant-garde cinema, New York City
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I’ve done numerous and had full-length films work at ProRes422.
If you’re worried then an h264 set to 22/18 will suffice.
These are MacBook Pro mostly.
My only beef was colorspace with all the different flavors of projectors.
That’s just a PITA. -
Stuttering usually means the playback device can’t decode it fast enough.
Were you playing from a memory stick?
If it was on the laptop drive itself perhaps something there is causing it.
Try a short test of a few minutes at 10mbps average with 14mbps max.
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Thanks
Kevin Dawson
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Thanks for the responses. Let me frame the question better. They want a mp4 file and and they will project on to the cinema screen from a windows 10 laptop…so pro res will be an issue (and I have never worked with 442 pro res on a windows computer). So my question is by dramatically increasing my target bit rate to say 40-50 with a H.264 format, I assume that I will have better quality (no stuttering, artifacts)) compared to a bit rate of 14? (especially with the video having a lot of panning and zooming and animation). Is that correct? Or Is there a diminishing returns point where higher bit rate mean no difference in playback quality?
My second related question is…have I created a second problem. …by increasing the bit rate, I have a huge file size. Does this mean that If the computer that is projecting on the cinema screen does not have a very fast processor and a fast hard drive, then I am back to where I started, where I will get problems with playback….stuttering freezing etc?
Kevin Dawson
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