Memory view rather than pointers (#144). Part of #141.

* Returning an object seems to work well

* This doesn't work

* This does!

* Better cast?

* Updating usage in Squoosh

codecs/mozjpeg_enc/README.md

@@ -19,26 +19,27 @@ See `example.html`
 
 Returns the version of MozJPEG as a number. va.b.c is encoded as 0x0a0b0c
 
-### `uint8_t* create_buffer(int width, int height)`
-
-Allocates an RGBA buffer for an image with the given dimension.
-
-### `void destroy_buffer(uint8_t* p)`
-
-Frees a buffer created with `create_buffer`.
-
-### `void encode(uint8_t* image_buffer, int image_width, int image_height, int quality)`
-
-Encodes the given image with given dimension to JPEG. `quality` is a number between 0 and 100. The higher the number, the better the quality of the encoded image. The result is implicitly stored and can be accessed using the `get_result_*()` functions.
-
 ### `void free_result()`
 
 Frees the result created by `encode()`.
 
-### `int get_result_pointer()`
+### `Uint8Array encode(std::string image_in, int image_width, int image_height, MozJpegOptions opts)`
 
-Returns the pointer to the start of the buffer holding the encoded data.
+Encodes the given image with given dimension to JPEG. Options looks like this:
 
-### `int get_result_size()`
-
-Returns the length of the buffer holding the encoded data.
+```c++
+struct MozJpegOptions {
+  int quality;
+  bool baseline;
+  bool arithmetic;
+  bool progressive;
+  bool optimize_coding;
+  int smoothing;
+  int color_space;
+  int quant_table;
+  bool trellis_multipass;
+  bool trellis_opt_zero;
+  bool trellis_opt_table;
+  int trellis_loops;
+};
+```

codecs/mozjpeg_enc/example.html

@@ -20,9 +20,7 @@
   module.onRuntimeInitialized = async _ => {
     console.log('Version:', module.version().toString(16));
     const image = await loadImage('../example.png');
-    const p = module.create_buffer(image.width, image.height);
-    module.HEAP8.set(image.data, p);
-    module.encode(p, image.width, image.height, {
+    const result = module.encode(image.data, image.width, image.height, {
       quality: 40,
       baseline: false,
       arithmetic: false,
@@ -36,13 +34,6 @@
       trellis_opt_table: true,
       trellis_loops: 1,
     });
-    const resultPointer = module.get_result_pointer();
-    const resultSize = module.get_result_size();
-    console.log('size', resultSize);
-    const resultView = new Uint8Array(module.HEAP8.buffer, resultPointer, resultSize);
-    const result = new Uint8Array(resultView);
-    module.free_result();
-    module.destroy_buffer(p);
 
     const blob = new Blob([result], {type: 'image/jpeg'});
     const blobURL = URL.createObjectURL(blob);

codecs/mozjpeg_enc/mozjpeg_enc.cpp

@@ -1,10 +1,10 @@
-#include "emscripten.h"
+#include <emscripten/bind.h>
+#include <emscripten/val.h>
 #include <stdlib.h>
 #include <inttypes.h>
 #include <stdio.h>
 #include <setjmp.h>
 #include <string.h>
-#include <emscripten/bind.h>
 #include "config.h"
 #include "jpeglib.h"
 #include "cdjpeg.h"
@@ -47,17 +47,10 @@ int version() {
   return version;
 }
 
-int create_buffer(int width, int height) {
-  return (int) malloc(width * height * 4 * sizeof(uint8_t));
-}
+uint8_t* last_result;
 
-void destroy_buffer(int p) {
-  free((uint8_t*) p);
-}
-
-int result[2];
-void encode(int image_in, int image_width, int image_height, MozJpegOptions opts) {
-  uint8_t* image_buffer = (uint8_t*) image_in;
+val encode(std::string image_in, int image_width, int image_height, MozJpegOptions opts) {
+  uint8_t* image_buffer = (uint8_t*) image_in.c_str();
 
   // The code below is basically the `write_JPEG_file` function from
   // https://github.com/mozilla/mozjpeg/blob/master/example.c
@@ -191,25 +184,17 @@ void encode(int image_in, int image_width, int image_height, MozJpegOptions opts
   jpeg_finish_compress(&cinfo);
   /* Step 7: release JPEG compression object */
 
-  result[0] = (int)output;
-  result[1] = size;
-
   /* This is an important step since it will release a good deal of memory. */
   jpeg_destroy_compress(&cinfo);
 
+  last_result = output;
+
   /* And we're done! */
+  return val(typed_memory_view(size, output));
 }
 
 void free_result() {
-  free((void*)result[0]); // not sure if this is right with mozjpeg
-}
-
-int get_result_pointer() {
-  return result[0];
-}
-
-int get_result_size() {
-  return result[1];
+  free(last_result); // not sure if this is right with mozjpeg
 }
 
 EMSCRIPTEN_BINDINGS(my_module) {
@@ -229,10 +214,6 @@ EMSCRIPTEN_BINDINGS(my_module) {
     ;
 
   function("version", &version);
-  function("create_buffer", &create_buffer, allow_raw_pointers());
-  function("destroy_buffer", &destroy_buffer, allow_raw_pointers());
-  function("encode", &encode, allow_raw_pointers());
+  function("encode", &encode);
   function("free_result", &free_result);
-  function("get_result_pointer", &get_result_pointer, allow_raw_pointers());
-  function("get_result_size", &get_result_size, allow_raw_pointers());
 }

codecs/mozjpeg_enc/mozjpeg_enc.d.ts

@@ -1,13 +1,8 @@
 import { EncodeOptions } from '../../src/codecs/mozjpeg/encoder';
 
 interface MozJPEGModule extends EmscriptenWasm.Module {
-  create_buffer(width: number, height: number): number;
-  encode(pointer: number, width: number, height: number, options: EncodeOptions): void;
-  get_result_pointer(): number;
-  get_result_size(): number;
+  encode(data: BufferSource, width: number, height: number, options: EncodeOptions): Uint8Array;
   free_result(): void;
-  destroy_buffer(pointer: number): void;
 }
 
-
 export default function(opts: EmscriptenWasm.ModuleOpts): MozJPEGModule;

codecs/webp_enc/README.md

@@ -17,26 +17,10 @@ See `example.html`
 
 Returns the version of libwebp as a number. va.b.c is encoded as 0x0a0b0c
 
-### `uint8_t* create_buffer(int width, int height)`
+### `UInt8Array encode(uint8_t* image_buffer, int image_width, int image_height, WebPConfig config)`
 
-Allocates an RGBA buffer for an image with the given dimension.
-
-### `void destroy_buffer(uint8_t* p)`
-
-Frees a buffer created with `create_buffer`.
-
-### `void encode(uint8_t* image_buffer, int image_width, int image_height, float quality)`
-
-Encodes the given image with given dimension to WebP. `quality` is a number between 0 and 100. The higher the number, the better the quality of the encoded image. The result is implicitly stored and can be accessed using the `get_result_*()` functions.
+Encodes the given image with given dimension to WebP.
 
 ### `void free_result()`
 
-Frees the result created by `encode()`.
-
-### `int get_result_pointer()`
-
-Returns the pointer to the start of the buffer holding the encoded data.
-
-### `int get_result_size()`
-
-Returns the length of the buffer holding the encoded data.
+Frees the last result created by `encode()`.

codecs/webp_enc/example.html

@@ -20,14 +20,11 @@
   module.onRuntimeInitialized = async _ => {
     console.log('Version:', module.version().toString(16));
     const image = await loadImage('../example.png');
-    const p = module.create_buffer(image.width, image.height);
-    module.HEAP8.set(image.data, p);
-    module.encode(p, image.width, image.height, {
-      quality: 100,
-      image_hint: 0,
+    const result = module.encode(image.data, image.width, image.height, {
+      quality: 75,
       target_size: 0,
       target_PSNR: 0,
-      method: 6,
+      method: 4,
       sns_strength: 50,
       filter_strength: 60,
       filter_sharpness: 0,
@@ -42,7 +39,7 @@
       alpha_compression: 1,
       alpha_filtering: 1,
       alpha_quality: 100,
-      lossless: 1,
+      lossless: 0,
       exact: 0,
       image_hint: 0,
       emulate_jpeg_size: 0,
@@ -52,15 +49,11 @@
       use_delta_palette: 0,
       use_sharp_yuv: 0,
     });
-    const resultPointer = module.get_result_pointer();
-    const resultSize = module.get_result_size();
-    console.log('size', resultSize);
-    const resultView = new Uint8Array(module.HEAP8.buffer, resultPointer, resultSize);
-    const result = new Uint8Array(resultView);
-    module.free_result();
-    module.destroy_buffer(p);
-
+    console.log('size', result.length);
     const blob = new Blob([result], {type: 'image/webp'});
+
+    module.free_result();
+
     const blobURL = URL.createObjectURL(blob);
     const img = document.createElement('img');
     img.src = blobURL;

codecs/webp_enc/webp_enc.cpp

@@ -1,7 +1,9 @@
-#include "emscripten.h"
+#include <emscripten/bind.h>
+#include <emscripten/val.h>
 #include "src/webp/encode.h"
 #include <stdlib.h>
-#include <emscripten/bind.h>
+#include <string.h>
+#include <stdexcept>
 
 using namespace emscripten;
 
@@ -9,23 +11,19 @@ int version() {
   return WebPGetEncoderVersion();
 }
 
-int create_buffer(int width, int height) {
-  return (int) malloc(width * height * 4 * sizeof(uint8_t));
-}
+uint8_t* last_result;
 
-void destroy_buffer(int p) {
-  free((uint8_t*) p);
-}
+val encode(std::string img, int width, int height, WebPConfig config) {
+  uint8_t* img_in = (uint8_t*) img.c_str();
 
-int result[2];
-void encode(int img_in, int width, int height, WebPConfig config) {
   // A lot of this is duplicated from Encode in picture_enc.c
   WebPPicture pic;
   WebPMemoryWriter wrt;
   int ok;
 
   if (!WebPPictureInit(&pic)) {
-    return;  // shouldn't happen, except if system installation is broken
+    // shouldn't happen, except if system installation is broken
+    throw std::runtime_error("Unexpected error");
   }
 
   pic.use_argb = !!config.lossless;
@@ -40,23 +38,18 @@ void encode(int img_in, int width, int height, WebPConfig config) {
   WebPPictureFree(&pic);
   if (!ok) {
     WebPMemoryWriterClear(&wrt);
-    return;
+    throw std::runtime_error("Encode failed");
   }
-  result[0] = (int)wrt.mem;
-  result[1] = wrt.size;
+
+  last_result = wrt.mem;
+
+  return val(typed_memory_view(wrt.size, wrt.mem));
 }
 
 void free_result() {
-  WebPFree((void*)result[0]);
+  WebPFree(last_result);
 }
 
-int get_result_pointer() {
-  return result[0];
-}
-
-int get_result_size() {
-  return result[1];
-}
 
 EMSCRIPTEN_BINDINGS(my_module) {
   enum_<WebPImageHint>("WebPImageHint")
@@ -97,10 +90,6 @@ EMSCRIPTEN_BINDINGS(my_module) {
     ;
 
   function("version", &version);
-  function("create_buffer", &create_buffer, allow_raw_pointers());
-  function("destroy_buffer", &destroy_buffer, allow_raw_pointers());
-  function("encode", &encode, allow_raw_pointers());
+  function("encode", &encode);
   function("free_result", &free_result);
-  function("get_result_pointer", &get_result_pointer, allow_raw_pointers());
-  function("get_result_size", &get_result_size, allow_raw_pointers());
 }

codecs/webp_enc/webp_enc.d.ts

@@ -1,12 +1,8 @@
 import { EncodeOptions } from '../../src/codecs/webp/encoder';
 
 interface WebPModule extends EmscriptenWasm.Module {
-  create_buffer(width: number, height: number): number;
-  encode(pointer: number, width: number, height: number, options: EncodeOptions): void;
-  get_result_pointer(): number;
-  get_result_size(): number;
+  encode(data: BufferSource, width: number, height: number, options: EncodeOptions): Uint8Array;
   free_result(): void;
-  destroy_buffer(pointer: number): void;
 }
 
 

src/codecs/mozjpeg/Encoder.worker.ts

@@ -33,16 +33,9 @@ export default class MozJpegEncoder {
 
   async encode(data: ImageData, options: EncodeOptions): Promise<ArrayBuffer> {
     const module = await this.emscriptenModule;
-
-    const p = module.create_buffer(data.width, data.height);
-    module.HEAP8.set(data.data, p);
-    module.encode(p, data.width, data.height, options);
-    const resultPointer = module.get_result_pointer();
-    const resultSize = module.get_result_size();
-    const resultView = new Uint8Array(module.HEAP8.buffer, resultPointer, resultSize);
+    const resultView = module.encode(data.data, data.width, data.height, options);
     const result = new Uint8Array(resultView);
     module.free_result();
-    module.destroy_buffer(p);
 
     // wasm can’t run on SharedArrayBuffers, so we hard-cast to ArrayBuffer.
     return result.buffer as ArrayBuffer;

src/codecs/webp/Encoder.worker.ts

@@ -34,17 +34,10 @@ export default class WebPEncoder {
   async encode(data: ImageData, options: EncodeOptions): Promise<ArrayBuffer> {
     const module = await this.emscriptenModule;
 
-    const p = module.create_buffer(data.width, data.height);
-    module.HEAP8.set(data.data, p);
-    module.encode(p, data.width, data.height, options);
-    const resultPointer = module.get_result_pointer();
-    const resultSize = module.get_result_size();
-    const resultView = new Uint8Array(module.HEAP8.buffer, resultPointer, resultSize);
+    const resultView = module.encode(data.data, data.width, data.height, options);
     const result = new Uint8Array(resultView);
     module.free_result();
-    module.destroy_buffer(p);
 
-    // wasm can’t run on SharedArrayBuffers, so we hard-cast to ArrayBuffer.
     return result.buffer as ArrayBuffer;
   }
 }