f523db6403
See the discussion in https://github.com/AOMediaCodec/libavif/issues/254 where this was implemented. This allows us to avoid using ERROR_ON_UNDEFINED_SYMBOLS and build a truly separate encoder/decoder libs.
49 lines
1.6 KiB
C++
49 lines
1.6 KiB
C++
#include <emscripten/bind.h>
|
|
#include <emscripten/val.h>
|
|
#include "avif/avif.h"
|
|
|
|
using namespace emscripten;
|
|
|
|
thread_local const val Uint8ClampedArray = val::global("Uint8ClampedArray");
|
|
thread_local const val ImageData = val::global("ImageData");
|
|
|
|
val decode(std::string avifimage) {
|
|
avifImage* image = avifImageCreateEmpty();
|
|
avifDecoder* decoder = avifDecoderCreate();
|
|
avifResult decodeResult =
|
|
avifDecoderReadMemory(decoder, image, (uint8_t*)avifimage.c_str(), avifimage.length());
|
|
// image is an independent copy of decoded data, decoder may be destroyed here
|
|
avifDecoderDestroy(decoder);
|
|
|
|
val result = val::null();
|
|
|
|
if (decodeResult == AVIF_RESULT_OK) {
|
|
// Convert to interleaved RGB(A)/BGR(A) using a libavif-allocated buffer.
|
|
avifRGBImage rgb;
|
|
avifRGBImageSetDefaults(&rgb,
|
|
image); // Defaults to AVIF_RGB_FORMAT_RGBA which is what we want.
|
|
rgb.depth = 8; // Does not need to match image->depth. We always want 8-bit pixels.
|
|
|
|
avifRGBImageAllocatePixels(&rgb);
|
|
avifImageYUVToRGB(image, &rgb);
|
|
|
|
// We want to create a *copy* of the decoded data to be owned by the JavaScript side.
|
|
// For that, we perform `new Uint8Array(wasmMemBuffer, wasmPtr, wasmSize).slice()`:
|
|
result = ImageData.new_(
|
|
Uint8ClampedArray.new_(typed_memory_view(rgb.rowBytes * rgb.height, rgb.pixels)), rgb.width,
|
|
rgb.height);
|
|
|
|
// Now we can safely free the RGB pixels:
|
|
avifRGBImageFreePixels(&rgb);
|
|
}
|
|
|
|
// Image has been converted to RGB, we don't need the original anymore.
|
|
avifImageDestroy(image);
|
|
|
|
return result;
|
|
}
|
|
|
|
EMSCRIPTEN_BINDINGS(my_module) {
|
|
function("decode", &decode);
|
|
}
|