Hey guys, I've searched the forum but can't seem to find anything that answers my question:
How do I reduce the file size of my exported movie?
Currently I'm working on a 60 minute video and regardless of frame rate or resolution I receive a warning that the file will be 11.1GB.
Cheers,
Merse
Movie file size
Re: Movie file size
In most cases you don't actually have to worry about that warning. In fact I should probably remove it, because it only applies to Windows 7. Windows 8 and 10 support larger sizes than 4GB, and I think OS X does also.
Magic calculates a very rough estimate of the file size based on the bitrate and the duration. But the bitrate is the maximum possible value, and many of the frames won't need the maximum. So it's likely that the file will be significantly smaller than predicted.
Let me know if that helps.
Magic calculates a very rough estimate of the file size based on the bitrate and the duration. But the bitrate is the maximum possible value, and many of the frames won't need the maximum. So it's likely that the file will be significantly smaller than predicted.
Let me know if that helps.
Re: Movie file size
Thanks Eric, but I'd still like the ability to make my file sizes smaller - a 1280x720 movie of 60 minutes came out at 11GB and it's taken me all day to upload it over my shitty broadband 
Anyway for me to understand the impact of reducing resolution, frame rate etc. to reduce final file size?
Will do a low res export and compare, am on OSX btw.
Regards,
Merse
Anyway for me to understand the impact of reducing resolution, frame rate etc. to reduce final file size?
Will do a low res export and compare, am on OSX btw.
Regards,
Merse
Re: Movie file size
The only things that affect the file size are the bitrate and the duration. Thus, with a constant duration of 60 minutes (3600 seconds), you can adjust the bitrate to get the file size you want.
The file size calculation is as follows: (duration in seconds) * (megabit rate / 8) = file size in megabytes
Doing some algebra, the bitrate can be obtained this way: megabit rate = ((file size in megabytes) / (duration in seconds)) * 8
So, let's say you wanted a file size of 1000MB (1GB): (1000/3600) * 8 = 2.2 Mbits/sec. The problem is that the quality of this movie will be pretty awful -- there will be lots of horrible compression artifacts. I highly recommend you don't go lower than 20 Mbits/sec for 1280x720.
No matter what you do, any reasonably good-quality HD movie that is an hour long will be several gigabytes. For comparison, here is the bitrate section on the Wikipedia page for Blu-Ray discs: https://en.wikipedia.org/wiki/Blu-ray#Bit_rate. You can see that the default bitrate is 36 Mbits/sec (which includes a small allowance for audio). A single-layer Blu-Ray disc holds 25GB, allowing for around 2 hours of content at good quality. And that's pretty much what you're getting with 11.1GB for one hour. Anything lower is going to reduce the quality, especially because Magic's abstract effects tend to have a lot more detail than natural camera footage.
On my list of things to add is a way to specify export quality (0-100) instead of bitrate, but the file size issue will remain more or less the same.
The file size calculation is as follows: (duration in seconds) * (megabit rate / 8) = file size in megabytes
Doing some algebra, the bitrate can be obtained this way: megabit rate = ((file size in megabytes) / (duration in seconds)) * 8
So, let's say you wanted a file size of 1000MB (1GB): (1000/3600) * 8 = 2.2 Mbits/sec. The problem is that the quality of this movie will be pretty awful -- there will be lots of horrible compression artifacts. I highly recommend you don't go lower than 20 Mbits/sec for 1280x720.
No matter what you do, any reasonably good-quality HD movie that is an hour long will be several gigabytes. For comparison, here is the bitrate section on the Wikipedia page for Blu-Ray discs: https://en.wikipedia.org/wiki/Blu-ray#Bit_rate. You can see that the default bitrate is 36 Mbits/sec (which includes a small allowance for audio). A single-layer Blu-Ray disc holds 25GB, allowing for around 2 hours of content at good quality. And that's pretty much what you're getting with 11.1GB for one hour. Anything lower is going to reduce the quality, especially because Magic's abstract effects tend to have a lot more detail than natural camera footage.
On my list of things to add is a way to specify export quality (0-100) instead of bitrate, but the file size issue will remain more or less the same.
Re: Movie file size
Ah that's useful, thanks Eric My test file came out at 4GB by dropping the frame rate to 24.
Will look at the maths, really helpful!
M
My test file came out at 4GB by dropping the frame rate to 24.Will look at the maths, really helpful!
M