Any one has an idea why exporting to animated gif file is so slow in Mathematica? Sometimes it takes many long minutes to export 500 or 1000 frames. Using V12.1 but is was also slow in V12.

@Nasser Have you tried exporting each frame as a separate image to e.g. .png and compared how long that takes? I suspect that rasterization is the lion part of the work.

I have a feeling that perhaps the question should rather be why rasterizing graphics is so slow.

@Nasser @C.E. It's always been like this, unfortunately. :-( I think it's not about the rendering speed but transferring the graphics boxes to the FE and processing them into a renderable format. Once some graphics has been shown, rescaling it or rotating it is very fast, many frames per second. But showing it for the first time is extremely slow.

Yes, it's the rasterization, I don't think much can be done ...

@C.E. Have you used machine learning stuff in Mma? Do you know what the NeuralNetwork method page got so barebones in 12.0?

This is 11.3: reference.wolfram.com/legacy/language/v11.3/ref/method/…

This is the current: reference.wolfram.com/language/ref/method/NeuralNetwork.html

See under Details and Suboptions.

There's the common situation where you finally put together some processing pipeline in a notebook and now you want to apply it to many datasets, programmatically. What workflow do people use?

I usually try to wrap it up into a function, but that's always so painful. It involved copying code, merging cells (which messes up indentation because it uses newlines instead of indenting newlines). It should not be this painful.

Maybe I should make an auto-generated package and "parametrize" it by setting global variables, then load it multipe times with Get

Any other tips?

@Nasser Although once you get to that number of frames I would definitely use MP4 instead of GIF.

The quality to filesize will be much better. I haven't tried Mathematica for MP4 exports, but if that doesn't work well you can always load the frames into free Blender, which has great video compression/export options.

cdn.discordapp.com/attachments/361656183377100801/…

That's a 1000 frame video I made over the summer while learning Unreal Engine that looks pretty good full screen and is just over 6 MB.

And in the Discord chat room where I uploaded it, it generated an inline view of the video just like a GIF.

It was quite some time ago since I exported decent sized mp4s with Mathematica, but my experience was that it was slow and prone to crashing. In the end, what worked better for me was to export every frame as an image and then convert it to a movie using ffmpeg, then if Mathematica crashed I could just continue from the last image I exported.

@Szabolcs I've used it some but I do not know this, unfortunately.

I would discourage anyone from trying to use Mathematica to process video. I have regretted it every time. The front end crashes all the time, and it's extremely slow. If you have to, create a RAM disk, and process it with only one frame in memory at a time, outputting the frames to PNG. Then use ffmpeg to encode the frames to something reasonable.

I've also noticed that the new .MP4 exporter produces files that QuickTimer Player cannot decode on macOS 10.15.4. Can any other 12.1 Mac users confirm? I just used the Export example in the .MP4 documentation.