swig: add python (decode) support

similar to Java, simple interface only

Change-Id: I8a3d344e5d89f73627e4e0cb2067512260d46fdd
(cherry picked from commit f980faf417)

swig/README

@@ -37,3 +37,20 @@ public class libwebp_jni_example {
 
  $ javac -cp libwebp.jar libwebp_jni_example.java
  $ java -Djava.library.path=. -cp libwebp.jar:. libwebp_jni_example
+
+Python SWIG bindings:
+---------------------
+ $ python setup.py build_ext
+ $ python setup.py install --prefix=pylocal
+
+-------------------------------------- BEGIN PSEUDO EXAMPLE
+import glob
+import sys
+sys.path.append(glob.glob('pylocal/lib/python*/site-packages')[0])
+
+from com.google.webp import libwebp
+print "libwebp decoder version: %x" % libwebp.WebPGetDecoderVersion()
+
+print "libwebp attributes:"
+for attr in dir(libwebp): print attr
+-------------------------------------- END PSEUDO EXAMPLE

swig/libwebp.i

@@ -8,15 +8,26 @@
 // libwebp swig interface definition
 //
 // Author: James Zern (jzern@google.com)
-//
-// For java bindings compile with:
-//  $ mkdir -p java/com/google/webp
-//  $ swig -ignoremissing -I../src \
-//         -java \
-//         -package com.google.webp \
-//         -outdir java/com/google/webp \
-//         -o libwebp_java_wrap.c libwebp.i
+
+/*
+  Java bindings:
+  $ mkdir -p java/com/google/webp
+  $ swig -java \
+         -package com.google.webp \
+         -outdir java/com/google/webp \
+         -o libwebp_java_wrap.c libwebp.i
+
+  Python bindings:
+  $ swig -python \
+         -outdir . \
+         -o libwebp_python_wrap.c libwebp.i
+*/
+
+#ifdef SWIGPYTHON
+%module(package="com.google.webp") libwebp
+#else
 %module libwebp
+#endif  /* SWIGPYTHON */
 
 %include "constraints.i"
 %include "typemaps.i"
@@ -31,6 +42,14 @@
 %apply signed char[] { uint8_t* }
 #endif  /* SWIGJAVA */
 
+#ifdef SWIGPYTHON
+%apply (char* STRING, size_t LENGTH) { (const uint8_t* data, size_t data_size) }
+%typemap(out) uint8_t* {
+  $result = PyString_FromStringAndSize(
+      (const char*)$1, ReturnedBufferSize("$symname", arg3, arg4));
+}
+#endif  /* SWIGPYTHON */
+
 //------------------------------------------------------------------------------
 // Decoder specific
 
@@ -76,14 +95,19 @@ int WebPGetEncoderVersion(void);
 #ifdef SWIGJAVA
 %{
 #define FillMeInAsSizeCannotBeDeterminedAutomatically \
-    (result ? ReturnedBufferSize(__FUNCTION__, arg3, arg4) : 0)
+    (result ? (jint)ReturnedBufferSize(__FUNCTION__, arg3, arg4) : 0)
+%}
+#endif  /* SWIGJAVA */
 
-static jint ReturnedBufferSize(
+#if defined(SWIGJAVA) || defined(SWIGPYTHON)
+%{
+static size_t ReturnedBufferSize(
     const char* function, int* width, int* height) {
   static const struct sizemap {
     const char* function;
     int size_multiplier;
   } size_map[] = {
+#ifdef SWIGJAVA
     { "Java_com_google_webp_libwebpJNI_WebPDecodeRGB",  3 },
     { "Java_com_google_webp_libwebpJNI_WebPDecodeRGBA", 4 },
     { "Java_com_google_webp_libwebpJNI_WebPDecodeARGB", 4 },
@@ -97,12 +121,20 @@ static jint ReturnedBufferSize(
     { "Java_com_google_webp_libwebpJNI_wrap_1WebPEncodeLosslessBGR",  1 },
     { "Java_com_google_webp_libwebpJNI_wrap_1WebPEncodeLosslessRGBA", 1 },
     { "Java_com_google_webp_libwebpJNI_wrap_1WebPEncodeLosslessBGRA", 1 },
+#endif
+#ifdef SWIGPYTHON
+    { "WebPDecodeRGB",  3 },
+    { "WebPDecodeRGBA", 4 },
+    { "WebPDecodeARGB", 4 },
+    { "WebPDecodeBGR",  3 },
+    { "WebPDecodeBGRA", 4 },
+#endif
     { NULL, 0 }
   };
   const struct sizemap* p;
-  jint size = -1;
+  size_t size = 0;
 
-  for (p = size_map; p->function; p++) {
+  for (p = size_map; p->function; ++p) {
     if (!strcmp(function, p->function)) {
       size = *width * *height * p->size_multiplier;
       break;
@@ -112,10 +144,9 @@ static jint ReturnedBufferSize(
   return size;
 }
 %}
-#endif  /* SWIGJAVA */
+#endif  /* SWIGJAVA || SWIGPYTHON */
 
 %{
-
 typedef size_t (*WebPEncodeFunction)(const uint8_t* rgb,
                                      int width, int height, int stride,
                                      float quality_factor, uint8_t** output);

swig/libwebp.py

@@ -0,0 +1,136 @@
+# This file was automatically generated by SWIG (http://www.swig.org).
+# Version 2.0.4
+#
+# Do not make changes to this file unless you know what you are doing--modify
+# the SWIG interface file instead.
+
+
+
+from sys import version_info
+if version_info >= (2,6,0):
+    def swig_import_helper():
+        from os.path import dirname
+        import imp
+        fp = None
+        try:
+            fp, pathname, description = imp.find_module('_libwebp', [dirname(__file__)])
+        except ImportError:
+            import _libwebp
+            return _libwebp
+        if fp is not None:
+            try:
+                _mod = imp.load_module('_libwebp', fp, pathname, description)
+            finally:
+                fp.close()
+            return _mod
+    _libwebp = swig_import_helper()
+    del swig_import_helper
+else:
+    import _libwebp
+del version_info
+try:
+    _swig_property = property
+except NameError:
+    pass # Python < 2.2 doesn't have 'property'.
+def _swig_setattr_nondynamic(self,class_type,name,value,static=1):
+    if (name == "thisown"): return self.this.own(value)
+    if (name == "this"):
+        if type(value).__name__ == 'SwigPyObject':
+            self.__dict__[name] = value
+            return
+    method = class_type.__swig_setmethods__.get(name,None)
+    if method: return method(self,value)
+    if (not static):
+        self.__dict__[name] = value
+    else:
+        raise AttributeError("You cannot add attributes to %s" % self)
+
+def _swig_setattr(self,class_type,name,value):
+    return _swig_setattr_nondynamic(self,class_type,name,value,0)
+
+def _swig_getattr(self,class_type,name):
+    if (name == "thisown"): return self.this.own()
+    method = class_type.__swig_getmethods__.get(name,None)
+    if method: return method(self)
+    raise AttributeError(name)
+
+def _swig_repr(self):
+    try: strthis = "proxy of " + self.this.__repr__()
+    except: strthis = ""
+    return "<%s.%s; %s >" % (self.__class__.__module__, self.__class__.__name__, strthis,)
+
+try:
+    _object = object
+    _newclass = 1
+except AttributeError:
+    class _object : pass
+    _newclass = 0
+
+
+
+def WebPGetDecoderVersion():
+  return _libwebp.WebPGetDecoderVersion()
+WebPGetDecoderVersion = _libwebp.WebPGetDecoderVersion
+
+def WebPGetInfo(*args):
+  return _libwebp.WebPGetInfo(*args)
+WebPGetInfo = _libwebp.WebPGetInfo
+
+def WebPDecodeRGB(*args):
+  return _libwebp.WebPDecodeRGB(*args)
+WebPDecodeRGB = _libwebp.WebPDecodeRGB
+
+def WebPDecodeRGBA(*args):
+  return _libwebp.WebPDecodeRGBA(*args)
+WebPDecodeRGBA = _libwebp.WebPDecodeRGBA
+
+def WebPDecodeARGB(*args):
+  return _libwebp.WebPDecodeARGB(*args)
+WebPDecodeARGB = _libwebp.WebPDecodeARGB
+
+def WebPDecodeBGR(*args):
+  return _libwebp.WebPDecodeBGR(*args)
+WebPDecodeBGR = _libwebp.WebPDecodeBGR
+
+def WebPDecodeBGRA(*args):
+  return _libwebp.WebPDecodeBGRA(*args)
+WebPDecodeBGRA = _libwebp.WebPDecodeBGRA
+
+def WebPGetEncoderVersion():
+  return _libwebp.WebPGetEncoderVersion()
+WebPGetEncoderVersion = _libwebp.WebPGetEncoderVersion
+
+def wrap_WebPEncodeRGB(*args):
+  return _libwebp.wrap_WebPEncodeRGB(*args)
+wrap_WebPEncodeRGB = _libwebp.wrap_WebPEncodeRGB
+
+def wrap_WebPEncodeBGR(*args):
+  return _libwebp.wrap_WebPEncodeBGR(*args)
+wrap_WebPEncodeBGR = _libwebp.wrap_WebPEncodeBGR
+
+def wrap_WebPEncodeRGBA(*args):
+  return _libwebp.wrap_WebPEncodeRGBA(*args)
+wrap_WebPEncodeRGBA = _libwebp.wrap_WebPEncodeRGBA
+
+def wrap_WebPEncodeBGRA(*args):
+  return _libwebp.wrap_WebPEncodeBGRA(*args)
+wrap_WebPEncodeBGRA = _libwebp.wrap_WebPEncodeBGRA
+
+def wrap_WebPEncodeLosslessRGB(*args):
+  return _libwebp.wrap_WebPEncodeLosslessRGB(*args)
+wrap_WebPEncodeLosslessRGB = _libwebp.wrap_WebPEncodeLosslessRGB
+
+def wrap_WebPEncodeLosslessBGR(*args):
+  return _libwebp.wrap_WebPEncodeLosslessBGR(*args)
+wrap_WebPEncodeLosslessBGR = _libwebp.wrap_WebPEncodeLosslessBGR
+
+def wrap_WebPEncodeLosslessRGBA(*args):
+  return _libwebp.wrap_WebPEncodeLosslessRGBA(*args)
+wrap_WebPEncodeLosslessRGBA = _libwebp.wrap_WebPEncodeLosslessRGBA
+
+def wrap_WebPEncodeLosslessBGRA(*args):
+  return _libwebp.wrap_WebPEncodeLosslessBGRA(*args)
+wrap_WebPEncodeLosslessBGRA = _libwebp.wrap_WebPEncodeLosslessBGRA
+# This file is compatible with both classic and new-style classes.
+
+

swig/libwebp_java_wrap.c

@@ -813,14 +813,16 @@ jdoubleArray SWIG_JavaArrayOutDouble (JNIEnv *jenv, double *result, jsize sz) {
 
 
 #define FillMeInAsSizeCannotBeDeterminedAutomatically \
-    (result ? ReturnedBufferSize(__FUNCTION__, arg3, arg4) : 0)
+    (result ? (jint)ReturnedBufferSize(__FUNCTION__, arg3, arg4) : 0)
 
-static jint ReturnedBufferSize(
+
+static size_t ReturnedBufferSize(
     const char* function, int* width, int* height) {
   static const struct sizemap {
     const char* function;
     int size_multiplier;
   } size_map[] = {
+#ifdef SWIGJAVA
     { "Java_com_google_webp_libwebpJNI_WebPDecodeRGB",  3 },
     { "Java_com_google_webp_libwebpJNI_WebPDecodeRGBA", 4 },
     { "Java_com_google_webp_libwebpJNI_WebPDecodeARGB", 4 },
@@ -834,12 +836,20 @@ static jint ReturnedBufferSize(
     { "Java_com_google_webp_libwebpJNI_wrap_1WebPEncodeLosslessBGR",  1 },
     { "Java_com_google_webp_libwebpJNI_wrap_1WebPEncodeLosslessRGBA", 1 },
     { "Java_com_google_webp_libwebpJNI_wrap_1WebPEncodeLosslessBGRA", 1 },
+#endif
+#ifdef SWIGPYTHON
+    { "WebPDecodeRGB",  3 },
+    { "WebPDecodeRGBA", 4 },
+    { "WebPDecodeARGB", 4 },
+    { "WebPDecodeBGR",  3 },
+    { "WebPDecodeBGRA", 4 },
+#endif
     { NULL, 0 }
   };
   const struct sizemap* p;
-  jint size = -1;
+  size_t size = 0;
 
-  for (p = size_map; p->function; p++) {
+  for (p = size_map; p->function; ++p) {
     if (!strcmp(function, p->function)) {
       size = *width * *height * p->size_multiplier;
       break;
@@ -850,7 +860,6 @@ static jint ReturnedBufferSize(
 }
 
 
-
 typedef size_t (*WebPEncodeFunction)(const uint8_t* rgb,
                                      int width, int height, int stride,
                                      float quality_factor, uint8_t** output);

swig/setup.py

@@ -0,0 +1,40 @@
+#!/usr/bin/python
+
+"""distutils script for libwebp python module."""
+
+from distutils.core import setup
+from distutils.extension import Extension
+import os
+import shutil
+import tempfile
+
+tmpdir = tempfile.mkdtemp()
+package = "com.google.webp"
+package_path = os.path.join(tmpdir, *package.split("."))
+os.makedirs(package_path)
+
+# Create __init_.py files along the package path.
+initpy_path = tmpdir
+for d in package.split("."):
+  initpy_path = os.path.join(initpy_path, d)
+  open(os.path.join(initpy_path, "__init__.py"), "w").close()
+
+shutil.copy2("libwebp.py", package_path)
+setup(name="libwebp",
+      version="0.0",
+      description="libwebp python wrapper",
+      long_description="Provides access to 'simple' libwebp decode interface",
+      license="BSD",
+      url="http://developers.google.com/speed/webp",
+      ext_package=package,
+      ext_modules=[Extension("_libwebp",
+                             ["libwebp_python_wrap.c"],
+                             libraries=["webp"],
+                            ),
+                  ],
+      package_dir={"": tmpdir},
+      packages=["com", "com.google", "com.google.webp"],
+      py_modules=[package + ".libwebp"],
+     )
+
+shutil.rmtree(tmpdir)