使用 GLSurfaceView 和 OpenGl 通过JNI 显示 YUV 数据

要在 GLSurfaceView 中显示 YUV 数据，你需要将 YUV 数据转换为 RGB 数据，然后将 RGB 数据传递给 OpenGL ES，最后在 GLSurfaceView 中显示。这个过程可以通过 JNI 来完成。

以下是一个简单的示例代码：

1. Java 代码：

public class YuvRenderer implements GLSurfaceView.Renderer {
    private static final String TAG = "YuvRenderer";
    private int mTextureId;
    private int mProgram;
    private int mPositionHandle;
    private int mTexCoordHandle;
    private int mYuvWidth;
    private int mYuvHeight;
    private ByteBuffer mYuvBuffer;

    public YuvRenderer() {
        mYuvWidth = 0;
        mYuvHeight = 0;
        mYuvBuffer = null;
    }

    public void setYuvData(int width, int height, byte[] yuvData) {
        mYuvWidth = width;
        mYuvHeight = height;
        mYuvBuffer = ByteBuffer.wrap(yuvData);
    }

    @Override
    public void onSurfaceCreated(GL10 gl, EGLConfig config) {
        GLES20.glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
        GLES20.glDisable(GLES20.GL_DEPTH_TEST);

        mProgram = createProgram();
        mPositionHandle = GLES20.glGetAttribLocation(mProgram, "aPosition");
        mTexCoordHandle = GLES20.glGetAttribLocation(mProgram, "aTexCoord");
        int textureUniformHandle = GLES20.glGetUniformLocation(mProgram, "uTexture");

        int[] textureIds = new int[1];
        GLES20.glGenTextures(1, textureIds, 0);
        mTextureId = textureIds[0];

        GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, mTextureId);
        GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_LINEAR);
        GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_LINEAR);
        GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_S, GLES20.GL_CLAMP_TO_EDGE);
        GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_T, GLES20.GL_CLAMP_TO_EDGE);

        GLES20.glTexImage2D(GLES20.GL_TEXTURE_2D, 0, GLES20.GL_RGBA, mYuvWidth / 2, mYuvHeight / 2, 0, GLES20.GL_RGBA, GLES20.GL_UNSIGNED_BYTE, null);

        GLES20.glUseProgram(mProgram);
        GLES20.glVertexAttribPointer(mPositionHandle, 2, GLES20.GL_FLOAT, false, 0, createVertexBuffer());
        GLES20.glVertexAttribPointer(mTexCoordHandle, 2, GLES20.GL_FLOAT, false, 0, createTexCoordBuffer());
        GLES20.glEnableVertexAttribArray(mPositionHandle);
        GLES20.glEnableVertexAttribArray(mTexCoordHandle);
        GLES20.glUniform1i(textureUniformHandle, 0);
    }

    @Override
    public void onSurfaceChanged(GL10 gl, int width, int height) {
        GLES20.glViewport(0, 0, width, height);
    }

    @Override
    public void onDrawFrame(GL10 gl) {
        if (mYuvBuffer == null) {
            GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
            return;
        }

        GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);

        byte[] yuvData = mYuvBuffer.array();
        int[] rgbData = new int[mYuvWidth * mYuvHeight];

        YuvUtils.convertYUV420ToRGB8888(yuvData, rgbData, mYuvWidth, mYuvHeight);

        GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, mTextureId);
        GLES20.glTexSubImage2D(GLES20.GL_TEXTURE_2D, 0, 0, 0, mYuvWidth / 2, mYuvHeight / 2, GLES20.GL_RGBA, GLES20.GL_UNSIGNED_BYTE, ByteBuffer.wrap(rgbData));
        GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, 4);
    }

    private int createProgram() {
        int vertexShader = loadShader(GLES20.GL_VERTEX_SHADER, VERTEX_SHADER_CODE);
        int fragmentShader = loadShader(GLES20.GL_FRAGMENT_SHADER, FRAGMENT_SHADER_CODE);

        int program = GLES20.glCreateProgram();
        GLES20.glAttachShader(program, vertexShader);
        GLES20.glAttachShader(program, fragmentShader);
        GLES20.glLinkProgram(program);

        return program;
    }

    private int loadShader(int shaderType, String shaderCode) {
        int shader = GLES20.glCreateShader(shaderType);
        GLES20.glShaderSource(shader, shaderCode);
        GLES20.glCompileShader(shader);
        return shader;
    }

    private FloatBuffer createVertexBuffer() {
        float[] vertexData = new float[] {
                -1.0f, -1.0f,
                1.0f, -1.0f,
                -1.0f, 1.0f,
                1.0f, 1.0f,
        };

        ByteBuffer byteBuffer = ByteBuffer.allocateDirect(vertexData.length * 4);
        byteBuffer.order(ByteOrder.nativeOrder());
        FloatBuffer buffer = byteBuffer.asFloatBuffer();
        buffer.put(vertexData);
        buffer.position(0);

        return buffer;
    }

    private FloatBuffer createTexCoordBuffer() {
        float[] texCoordData = new float[] {
                0.0f, 0.0f,
                1.0f, 0.0f,
                0.0f, 1.0f,
                1.0f, 1.0f,
        };

        ByteBuffer byteBuffer = ByteBuffer.allocateDirect(texCoordData.length * 4);
        byteBuffer.order(ByteOrder.nativeOrder());
        FloatBuffer buffer = byteBuffer.asFloatBuffer();
        buffer.put(texCoordData);
        buffer.position(0);

        return buffer;
    }

    private static final String VERTEX_SHADER_CODE =
            "attribute vec4 aPosition;\n" +
                    "attribute vec2 aTexCoord;\n" +
                    "varying vec2 vTexCoord;\n" +
                    "void main() {\n" +
                    "  gl_Position = aPosition;\n" +
                    "  vTexCoord = aTexCoord;\n" +
                    "}";

    private static final String FRAGMENT_SHADER_CODE =
            "precision mediump float;\n" +
                    "uniform sampler2D uTexture;\n" +
                    "varying vec2 vTexCoord;\n" +
                    "void main() {\n" +
                    "  gl_FragColor = texture2D(uTexture, vTexCoord);\n" +
                    "}";
}

2. JNI 代码：

JNIEXPORT void JNICALL Java_com_example_yuvrenderer_YuvRenderer_setYuvData(JNIEnv *env, jobject obj, jint width, jint height, jbyteArray yuvData) {
    jclass clazz = env->GetObjectClass(obj);

    jfieldID yuvWidthField = env->GetFieldID(clazz, "mYuvWidth", "I");
    jint yuvWidth = env->GetIntField(obj, yuvWidthField);

    jfieldID yuvHeightField = env->GetFieldID(clazz, "mYuvHeight", "I");
    jint yuvHeight = env->GetIntField(obj, yuvHeightField);

    jbyte* yuvDataPtr = env->GetByteArrayElements(yuvData, NULL);
    jsize yuvDataSize = env->GetArrayLength(yuvData);

    if (yuvWidth != width || yuvHeight != height) {
        env->SetIntField(obj, yuvWidthField, width);
        env->SetIntField(obj, yuvHeightField, height);
        jclass byteBufferClazz = env->FindClass("java/nio/ByteBuffer");
        jmethodID allocateDirectMethod = env->GetStaticMethodID(byteBufferClazz, "allocateDirect", "(I)Ljava/nio/ByteBuffer;");
        jobject yuvBuffer = env->CallStaticObjectMethod(byteBufferClazz, allocateDirectMethod, yuvDataSize);
        env->SetObjectField(obj, env->GetFieldID(clazz, "mYuvBuffer", "Ljava/nio/ByteBuffer;"), yuvBuffer);
    }

    jobject yuvBuffer = env->GetObjectField(obj, env->GetFieldID(clazz, "mYuvBuffer", "Ljava/nio/ByteBuffer;"));
    env->GetDirectBufferAddress(yuvBuffer);

    memcpy(yuvBufferPtr, yuvDataPtr, yuvDataSize);

    env->ReleaseByteArrayElements(yuvData, yuvDataPtr, JNI_ABORT);
}

这个示例代码中假设 YUV 数据是 NV21 格式的，你需要根据你的 YUV 数据格式进行相应的修改。