I have this code that will add some arrayBuffer to an array.
let buffer = [];
fetch(dataURI)
.then( (res) => res.arrayBuffer() )
.then( (data) => {
buffer.push(data);
});
I need to convert the resulting array into a single Int16Array to process it, I'm trying with this code but with no success. I'm unable to get the single Int16Array I need
buffer.forEach( (item) => {
samples = [...Int16Array.from(item)];
});
Any suggestion on how I can proceed?
maybe try this with Array.flat()
let I16 = buffer.map(a => new Int16Array(a)).flat()
There is something slightly off with this question, as a fetch request won't ever push more than once that data to the buffer, but I guess it's just an example of your use case, and your buffer gets populated multiple times by different fetches.
In any case, what I would use instead of .flat() after all things are pushed, is the following:
buffer.push(...data);
// or ...
buffer.push(...new Int16Array(data));
This will flatten out data right away so that once all fetches are completed, all you have to do is:
const i16a = Int16Array.from(buffer);
// or ...
const i16a = new Int16Array(buffer);
The previous mentioned solution would instead flatten the array without concatenating all received data so I think it won't work, accordingly with your request.
Uncaught (in promise) TypeError: Found non-callable @@iterator
buffer.push(...Int16Array.from(data)); instead? if that works, the rest wouldn't change (but I need to edit the answer if that's the case).buffer.push(...new Int8Array(data)) and I get this error Uncaught (in promise) RangeError: Maximum call stack size exceededbuffer.push(...i16a) or buffer.push(...Int16Array.from(data)) are exactly the same thing.You would have to map you buffers to int16 chunks and then concatenate those chunks into one array:
const int16Chunks = [];
let byteLength = 0;
fetch(dataURI)
.then(res => res.arrayBuffer())
.then(buffer => {
const chunk = createChunk(buffer, Int16Array.BYTES_PER_ELEMENT);
int16Chunks.push(chunk);
byteLength += chunk.byteLength;
});
later, when everything has been fetched:
const bytes = new Uint8Array(byteLength);
let offset = 0;
for (const chunk of int16Chunks) {
bytes.set(offset, chunk);
offset += chunk.length;
}
const result = new Int16Array(bytes.buffer);
finally, createChunk function:
function createChunk(buffer, step) {
const bytes = new Uint8Array(buffer);
const length = Math.ceil(bytes.length / step) * step;
const padded = new Uint8Array(length);
const offset = padded.length - bytes.length;
const chunk = padded.set(offset, bytes);
return chunk;
}
