You need to take another look at PNG... the QT video codec, that is: it does indeed support alpha channels! In general, the file sizes are bit smaller than Animation, plus it's a 10-bit codec. Like Animation, it is also lossless.
I can't speak to the duration of the file. It depends on what takes place in the animation, and how you plan to use it.
I think I found that PNG was kindof slow to render. I will give it another look.
The duration of the file question is really just about how AE manages its memory. Whether having a single file is better or many files. For game development, I am used to generating single spritesheets which contain all image data, rather than many small files. I am wondering if something similar is true with AE. I am basically trying to optimize our workflow as much as possible for maximum AE performance.
In the case of using one quicktime, it would be duplicated many times in AE, and time-remapped to break it apart into layers. Or it would simply already be broken apart as separate files. All files would be used all the time, as they are all the elements of a character's head rig (eyes, eyebrows, mouth, etc). In case you are wondering, the reason I want to prerender them is because they contain a lot of CPU-intensive effects (Mesh Warp, etc). These head rigs really slow down our workflow and also cause frequent crashes.
1 person found this helpful
For game development, I am used to generating single spritesheets which contain all image data, rather than many small files. I am wondering if something similar is true with AE.... In the case of using one quicktime, it would be duplicated many times in AE, and time-remapped to break it apart into layers. Or it would simply already be broken apart as separate files.
I would go with separate files with small vertical & horizontal dimensions as opposed to one file with giant H&V dimensions. Even if you have multiple instances of the same file, AE will treat each one individually as it composites. Thus, a separate file for eft eye, right eye, left eyebrow, right eyebrow & mouth will tend to render faster.
PNG only gives smaller files than Animation in cases of photorealistic images. Animation is better for cartoons (hence the name) because it's an RLE compressor; i.e., it encodes stretches of the same color very well.
I just gave PNG a try and it was less than half the size of Animation. However it is slower to encode and decode. Not sure why Animation is not more efficient in this case, maybe because the edges are somewhat soft. There are indeed large areas of one color, however.
1 person found this helpful
Try JPEG 2000 as well: in my testings it's about 1.5 times faster and provides of around 1.3 smaller file size compared to PNG.
JPEG 2000 seems to provide very good compression, has alpha, and is fast to encode. It is however the slowest of those I tested to decode.
In case you are curious, here's the results of my tests. I did not test encoding speed because it does not concern me.
Animation ---- 2.1 GB
ProRes 4x4 ---- 1.1 GB
PNG ---- 555 MB
JPEG2000 ---- 493 MB
Render Time (Decoding)
JPEG2000 ---- 21 min
PNG ---- 10 min
ProRes 4x4 ---- 9 min
Animation ---- 9 min
I think PNG is the winner. It is neither the most compressed nor the fastest but it is the best balance. Thank you for your advice!