add support for webp

PIL/WebPImagePlugin.py

@@ -0,0 +1,33 @@
+import Image
+import ImageFile
+import StringIO
+import _webp
+
+def _accept(prefix):
+    return prefix[:4] == "RIFF" and prefix[8:16] == "WEBPVP8 "
+
+class WebPImageFile(ImageFile.ImageFile):
+
+    format = "WEBP"
+    format_description = "WebP image"
+
+    def _open(self):
+        self.mode = "RGB"
+        data, width, height = _webp.WebPDecodeRGB(self.fp.read())
+        self.size = width, height
+        self.fp = StringIO.StringIO(data)
+        self.tile = [("raw", (0, 0) + self.size, 0, 'RGB')]
+
+def _save(im, fp, filename):
+    if im.mode != "RGB":
+        raise IOError("cannot write mode %s as WEBP" % im.mode)
+    quality = im.encoderinfo.get("quality", 80)
+    
+    data = _webp.WebPEncodeRGB(im.tostring(), im.size[0], im.size[1], im.size[0] * 3, float(quality))
+    fp.write(data)
+
+Image.register_open("WEBP", WebPImageFile, _accept)
+Image.register_save("WEBP", _save)
+
+Image.register_extension("WEBP", ".webp")
+Image.register_mime("WEBP", "image/webp")

_webp.c

@@ -0,0 +1,72 @@
+#include <Python.h>
+#include <webp/encode.h>
+#include <webp/decode.h>
+
+PyObject* WebPEncodeRGB_wrapper(PyObject* self, PyObject* args)
+{
+    PyStringObject *rgb_string;
+    int width;
+    int height;
+    int stride;
+    float quality_factor;
+
+    if (!PyArg_ParseTuple(args, "Siiif", &rgb_string, &width, &height, &stride, &quality_factor)) {
+        Py_INCREF(Py_None);
+        return Py_None;
+    }
+    
+    uint8_t *rgb;
+    Py_ssize_t size;
+    PyString_AsStringAndSize((struct PyObject *) rgb_string, &rgb, &size);
+
+    if (stride * height > size) {
+        Py_INCREF(Py_None);
+        return Py_None;
+    }
+
+    uint8_t *output;
+    size_t ret_size = WebPEncodeRGB(rgb, width, height, stride, quality_factor, &output);
+    if (ret_size > 0) {
+        PyObject *ret = PyString_FromStringAndSize(output, ret_size);
+        free(output);
+        return ret;
+    }
+    Py_INCREF(Py_None);
+    return Py_None;
+
+}
+
+PyObject* WebPDecodeRGB_wrapper(PyObject* self, PyObject* args)
+{
+    PyStringObject *webp_string;
+    float quality_factor;
+
+    if (!PyArg_ParseTuple(args, "S", &webp_string)) {
+        Py_INCREF(Py_None);
+        return Py_None;
+    }    
+    uint8_t *webp;
+    Py_ssize_t size;
+    PyString_AsStringAndSize((struct PyObject *) webp_string, &webp, &size);
+
+    int width;
+    int height;
+    uint8_t *output = WebPDecodeRGB(webp, size, &width, &height);
+
+    PyObject *ret = PyString_FromStringAndSize(output, width * height * 3);
+    free(output);
+    return Py_BuildValue("Sii", ret, width, height);
+}
+
+static PyMethodDef webpMethods[] =
+{
+    {"WebPEncodeRGB", WebPEncodeRGB_wrapper, METH_VARARGS, "WebPEncodeRGB"},
+    {"WebPDecodeRGB", WebPDecodeRGB_wrapper, METH_VARARGS, "WebPEncodeRGB"},
+    {NULL, NULL}
+};
+
+void init_webp()
+{
+    PyObject* m;
+    m = Py_InitModule("_webp", webpMethods);
+}

setup.py

@@ -211,7 +211,7 @@ class pil_build_ext(build_ext):
         # look for available libraries
 
         class feature:
-            zlib = jpeg = tiff = freetype = tcl = tk = lcms = None
+            zlib = jpeg = tiff = freetype = tcl = tk = lcms = webp = None
         feature = feature()
 
         if _find_include_file(self, "zlib.h"):
@@ -267,6 +267,10 @@ class pil_build_ext(build_ext):
             elif _find_library_file(self, "tk" + TCL_VERSION):
                 feature.tk = "tk" + TCL_VERSION
 
+        if _find_include_file(self, "webp/encode.h") and _find_include_file(self, "webp/decode.h"):
+            if _find_library_file(self, "webp"):
+                feature.webp = "webp"
+
         #
         # core library
 
@@ -314,6 +318,11 @@ class pil_build_ext(build_ext):
             exts.append(Extension(
                 "_imagingcms", ["_imagingcms.c"], libraries=["lcms"] + extra))
 
+        if os.path.isfile("_webp.c") and feature.webp:
+            exts.append(Extension(
+                "_webp", ["_webp.c"], libraries=["webp"]))
+
+
         if sys.platform == "darwin":
             # locate Tcl/Tk frameworks
             frameworks = []
@@ -376,6 +385,7 @@ class pil_build_ext(build_ext):
             # (feature.tiff, "experimental TIFF G3/G4 read"),
             (feature.freetype, "FREETYPE2"),
             (feature.lcms, "LITTLECMS"),
+            (feature.webp, "WEBP"),
             ]
 
         all = 1