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Adding Time Remapped Still Image to ProRes Timeline Adds 16-17GB
I ran into this strange situation with a job that should have been 5-10 minutes. I set up a very simple 1280×720 ProRes sequence which you can see a screen grab of below
The video starts out with a couple of Text Title Cards with a music track underneath and then shifts to an audio interview file. The interview is in wav format and is 436MB in size, about 40 minutes in duration.
Over the interview is a still image I imported (file size 406KB) which is a headshot of the person being interviewed. In order to have the still image stretch to the 40 minutes needed for the duration of the interview I used the motion tab, time remap function to “slow” down the still image to about 2% of it’s original “speed”)
That’s the entire project. Guess what kind of file sizes I got when I did a simple Export As Quicktime off the timeline?
18.2GB! If I took out the still headshot image that dropped to a 1.07GB ProRes movie file – which still seems huge but okay.
Thinking it had to do with the time remap of the headshot still image, I played around with setting up my Edit Options to import all still images in 40 minutes durations instead of the regular 10 seconds so that I wouldn’t have to do the time remap but I still was going to end up with a file size of at least 10GB (I aborted the export when I saw what it was doing)
What the hey is going on? Any ideas?
Steve Crow
Crow Digital Media
http://www.CrowDigitalMedia.com -
7 Replies
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According to the digital rebellion video data rate calculator a 720p movia of 40mintes in length in prores 422, should be 21+ GBs. So at 18.2 you’re way ahead of the game.
https://www.digitalrebellion.com/webapps/video_calc.html
The reason the version without a still in sequence is ONLY 1gig is because the solid black signal allowed for a unique efficiency in the ProRes codec. Other content won’t allow this. Doesn’t matter if it’s still or moving.
Couple of other thing. You can open a still in the viewer and type in a longer running time. Using the speed effect is the wrong way to do this.
Online Editor | Colorist | Post Super | VFX Artist | BD Author
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HI Juan,
Thank for responding. I wasn’t thinking about it that way for some reason…I was thinking that the content should somehow influence the final file size but maybe that’s not really the case.
Steve Crow
Crow Digital Media
http://www.CrowDigitalMedia.com -
This is what I-frame codecs (like prores) are all about. Each frame is a unique & individual snowflake, no matter what came before it.
Online Editor | Colorist | Post Super | VFX Artist | BD Author
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Yeah when I get a moment, I am going to prove this to myself by exporting two 30 second movies from the timeline with the only difference being one has a HD motion video on the timeline and the other is a low res still image – the file sizes will be the same.
Steve Crow
Crow Digital Media
http://www.CrowDigitalMedia.com -
[Steve Crow] “That’s the entire project. Guess what kind of file sizes I got when I did a simple Export As Quicktime off the timeline?
18.2GB! If I took out the still headshot image that dropped to a 1.07GB ProRes movie file – which still seems huge but okay.”
Do you think that 1.07GB for a 40 minutes Prores file is huge?
That’s ridiculous small.
Prores 1280x720p30 yields around 450MB per minute of film, so you should expect a file of around 18GB for your 40 minutes movie.The movie without the still is that small because every single pixel in every frame has the same YUV information and, as Juan points, prores is quite efficient on compressing that flat picture. Being a black makes the file even smaller than being a flat color, but as soon as you put an still where every pixel is different than the pixels around Prores can’t achieve the same level of compression.
The fact that every frame in the movie is the same, it doesn’t helps, because Prores is intraframe, and to compress its only looks what is inside the frame, not in the adjacent frames.
A GOP based codec yes, would reduce the file size.
rafael -
Steve
Can I suggest converting your WAV audio file to an aif 16bit 48k before placing it into the timeline.
Steve Eisen
Eisen Video Productions
Vice President
Chicago Final Cut Pro Users Group -
I did further testing just to satisfy my curiosity and what I found was that it is DATA RATE that is most to blame.
For instance, I just exported another video that was also 1280x720p, ProRes 422 and the file size came out to 195MB per minute which means a 40 minute video would have been 7.8GBs not the 18.2GBs I got with my earlier video that started this thread.
The only difference was in data rate – the first video was 58.88Mbps while this latest video was only 25.94Mbps- creating a much smaller file size
I didn’t specify any particular data rate, just selected Export as Quicktime/Current settings and let FCP do the work – for some reason it choose a much faster data rate for the first video
Oh and regarding the wav audio idea, I’ll look into that.
Thanks for the conversation guys
Steve Crow
Crow Digital Media
http://www.CrowDigitalMedia.com
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