jint problem with NDK - android-ndk

Question

I'm trying to make my first native function with NDK and I'm in trouble with very basic stuff.
Please consider the following c code:
#include <jni.h>
#include <string.h>
JNIEXPORT jint JNICALL Java_eu_elevelcbt_sm_YCrCbUtils_toARGB(
JNIEnv* env, jbyteArray src, jintArray out, jint width, jint height){
jbyte *c_src = (*env)->GetByteArrayElements(env, src, NULL);
jint *c_out = (*env)->GetDirectBufferAddress(env, out);
if (c_out==NULL)
return -1;
int length = width * height;
int co;
unsigned int color;
for (co=0; co<length; co++) {
color = c_src[co] & 0xFF;
color = 0xFF000000 | (color<<16) | (color<<8) | color;
c_out[co] = color;
}
(*env)->ReleaseByteArrayElements(env, src, c_src, 0);
return 0;
}
JNIEXPORT jint JNICALL Java_eu_elevelcbt_sm_YCrCbUtils_sum(jint a, jint b){
return a+b;
}
and the following Java class:
public class YCrCbUtils {
public native int toARGB(byte[] src, int[] out, final int width, final int height);
public native int sum(int a, int b);
static {
System.loadLibrary("yuv");
}
}
Problem 1: If I call the second function
Log.v("DBG", "sum is: " + new YCrCbUtils().sum(10, 5));
This is what I get: "sum is 1079199776" !!!! WHY?!??!? :(
If I try calling first function like this:
int[] colors = new int[size.width * size.height]; // where width=800 and height=480
new YCrCbUtils().toARGB(data, colors, size.width, size.height); // data is a byte[]
I get a SIGSEGV error...
HELP please!!!
PS: my dev environment is MAC OSX Snow Leopard, NDK-r5b. My runtime env is Nexus One 2.3.3

Answer 1

...ok I'm stupid...
My methods signatures were WRONG... They always must have "JNIEnv* env, jobject obj" as first two members... well I spend an afternoon on this but the good thing is that now I'll never forget it!
Also, on my first method I had to change
jint *c_out = (*env)->GetDirectBufferAddress(env, out);
with
jint *c_out = (*env)->GetIntArrayElements(env, out, NULL);
as the previous one was returning a NULL pointer