Crashes at 300+ Frames

[antimatter15]

Crashes at 300+ Frames

[joshi1983]

I ran into likely the same bug. I get the same error message after trying to encode 201 frames of a 512 by 512 resolution animation but I think the more critical detail is how large the compressed data is getting. It crashed shortly after the "outs" variable reached roughly 50 million elements. It is a ByteArray as defined in GIFEncoder.js which is repeatedly given more bytes using writeByte and writeBytes in the LZWEncoder.js. Eventually, the browser freezes for a few seconds before showing the error message above. The exact line of crash was outs.writeBytes(accum, 0, a_count) in the flush_char function of LZWEncoder.js while GIFEncoder is calling output on a pixel indirectly from the addFrame function. Immediately before that final call to writeBytes, outs = ByteArray { bin: Array(50139333)} according to Edge's debugger tools. I tried to encode the same animation in both Microsoft Edge and Google Chrome and it crashed on the same frame. I'm testing with a laptop that has 8GB of RAM.

I want to help you reproduce the problem so I'm sharing a prototype that tries to encode and download a gif as soon as you open it. When I open it in Edge, it encodes many frames but eventually crashes within a minute or so.
My prototype references a minified version but the problem is reproduced if you download and reference using script tags in the HTML file:
jsgif/LZWEncoder.js
jsgif/NeuQuant.js
jsgif/GIFEncoder.js
gifOutputBufferTooLarge.zip

Here is what I see after the crash in Microsoft Edge Version 113.0.1774.42 (Official build) (64-bit) in Windows 10:

I understand if the encoder runs out of RAM at some point but 50MB seems a little small for a maximum sized gif. Even if ByteArray can't expand beyond 50 million elements or so, a JavaScript Error or exception would be FAR more graceful than letting the browser tab completely crash. If GIFEncoder needs to be optimized for memory, a typed Array of 8-bit elements such as Uint8Array should use a small fraction of the memory.

[joshi1983]

Pull request #40 is open to tackle a large part of this problem by optimizing the data structure maintaining the encoded GIF data. I have it merged in my fork so if you want a more updated and stable jsgif, try my fork. antimatter15's repo looks like it has been dead for about 6 years.