扩展speia特效，支持任意RGB颜色变换矩阵，原理很简单，不解释



http://blog.csdn.net/lzf_china/article/details/44829049

    private void speiaHack(EffectFactory effectFactory,  float [] weights)
    {

        mEffect = effectFactory.createEffect(
                EffectFactory.EFFECT_SEPIA);

        try {
            Field field = Class.forName("android.media.effect.SingleFilterEffect").getDeclaredField("mFunction");
            field.setAccessible(true);
            Object mFunction = field.get(mEffect);
            Object mFilter =val(mFunction, "mFilter");
            Object mFilterContext =val(mFunction, "mFilterContext");
            Method initmethod = mFilter.getClass().getMethod("initProgram", new Class[]{Class.forName("android.filterfw.core.FilterContext"), int.class});
            initmethod.invoke(mFilter, new Object[]{mFilterContext, 3});
            Object mProgram =val(mFilter, "mProgram");
            Method method = mProgram.getClass().getMethod("setHostValue", new Class[]{String.class, Object.class});
            method.invoke(mProgram, new Object[]{"matrix", weights});
        } catch (Exception e) {
            e.printStackTrace();
        }
    }