Android - 如何使用opengl-es在3D立方体上渲染视频纹理?

时间:2014-12-09 09:34:15

标签: android opengl-es

我使用opengl-es

绘制一个3D立方体

https://db.tt/ktcbwtnD //这是图片,因为我在stackoverflow中是新的,所以我不能粘贴图片

我还通过引用此代码来渲染视频

public class VideoTextureRender implements Renderer, SurfaceTexture.OnFrameAvailableListener {
        private static String TAG = "VideoRender";

        private static final int FLOAT_SIZE_BYTES = 4;
        public static final int BYTES_PER_FLOAT = 4;
        private static final int TRIANGLE_VERTICES_DATA_STRIDE_BYTES = 5 * FLOAT_SIZE_BYTES;
        private static final int TRIANGLE_VERTICES_DATA_POS_OFFSET = 0;
        private static final int TRIANGLE_VERTICES_DATA_UV_OFFSET = 3;
        private static int count = 1;
        private final float[] mTriangleVerticesData = {
            // X, Y, Z, U, V
            -0.5f, -0.5f, 0, 0.f, 0.f,
            0.5f, -0.5f, 0, 1.f, 0.f,
            -0.5f,  0.5f, 0, 0.f, 1.f,
            0.5f,  0.5f, 0, 1.f, 1.f,

        };


        private FloatBuffer mTriangleVertices;

        private final String mVertexShader =
                "uniform mat4 uMVPMatrix;\n" +
                "uniform mat4 uSTMatrix;\n" +
                "attribute vec4 aPosition;\n" +
                "attribute vec4 aTextureCoord;\n" +
                "varying vec2 vTextureCoord;\n" +
                "void main() {\n" +
                "  gl_Position = uMVPMatrix * aPosition;\n" +
                "  vTextureCoord = (uSTMatrix * aTextureCoord).xy;\n" +
                "}\n";

        private final String mFragmentShader =
                "#extension GL_OES_EGL_image_external : require\n" +
                "precision mediump float;\n" +
                "varying vec2 vTextureCoord;\n" +
                "uniform samplerExternalOES sTexture;\n" +
                "void main() {\n" +
                "  gl_FragColor = texture2D(sTexture, vTextureCoord);\n" +
                "}\n";

        private float[] mMVPMatrix = new float[16];
        private float[] mSTMatrix = new float[16];

        private int mProgram;
        private int mTextureID;
        private int muMVPMatrixHandle;
        private int muSTMatrixHandle;
        private int maPositionHandle;
        private int maTextureHandle;

        private GLSurfaceViewActivity mGLSurfaceViewActivity;
        private SurfaceTexture mSurface;
        private boolean updateSurface = false;

        public static int GL_TEXTURE_EXTERNAL_OES = 0x8D65;

        private MediaPlayer mMediaPlayer;
        private Context context;

        public VideoTextureRender(Context Context) {
            mTriangleVertices = ByteBuffer.allocateDirect(
                    mTriangleVerticesData.length * FLOAT_SIZE_BYTES)
                        .order(ByteOrder.nativeOrder()).asFloatBuffer();
            mTriangleVertices.put(mTriangleVerticesData).position(0);

            Matrix.setIdentityM(mSTMatrix, 0);
        }

        public void setMediaPlayer(MediaPlayer player) {
            mMediaPlayer = player;
        }


        @Override
        public void onDrawFrame(GL10 glUnused) {

             synchronized(this) {
                    if (updateSurface) {
                        mSurface.updateTexImage();
                        mSurface.getTransformMatrix(mSTMatrix);
                        updateSurface = false;
                    }
                }


            GLES20.glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
            GLES20.glClear( GLES20.GL_DEPTH_BUFFER_BIT | GLES20.GL_COLOR_BUFFER_BIT);

            GLES20.glUseProgram(mProgram);
            checkGlError("glUseProgram");

            GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
            GLES20.glBindTexture(GL_TEXTURE_EXTERNAL_OES, mTextureID);

            mTriangleVertices.position(TRIANGLE_VERTICES_DATA_POS_OFFSET);
            GLES20.glVertexAttribPointer(maPositionHandle, 3, GLES20.GL_FLOAT, false,
                TRIANGLE_VERTICES_DATA_STRIDE_BYTES, mTriangleVertices);
            checkGlError("glVertexAttribPointer maPosition");
            GLES20.glEnableVertexAttribArray(maPositionHandle);
            checkGlError("glEnableVertexAttribArray maPositionHandle");

            mTriangleVertices.position(TRIANGLE_VERTICES_DATA_UV_OFFSET);
            GLES20.glVertexAttribPointer(maTextureHandle, 3, GLES20.GL_FLOAT, false,
                TRIANGLE_VERTICES_DATA_STRIDE_BYTES, mTriangleVertices);
            checkGlError("glVertexAttribPointer maTextureHandle");
            GLES20.glEnableVertexAttribArray(maTextureHandle);
            checkGlError("glEnableVertexAttribArray maTextureHandle");

            Matrix.setIdentityM(mMVPMatrix, 0);

            //rotateM(mSTMatrix, 0, count, 1f, 1f, 0f);

            GLES20.glUniformMatrix4fv(muMVPMatrixHandle, 1, false, mMVPMatrix, 0);
            GLES20.glUniformMatrix4fv(muSTMatrixHandle, 1, false, mSTMatrix, 0);

            GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, 4);
            checkGlError("glDrawArrays");
            GLES20.glFinish();

        }

        @Override
        public void onSurfaceChanged(GL10 glUnused, int width, int height) {

        }

        @Override
        public void onSurfaceCreated(GL10 glUnused, EGLConfig config) {

            mProgram = createProgram(mVertexShader, mFragmentShader);
            if (mProgram == 0) {
                return;
            }
            maPositionHandle = GLES20.glGetAttribLocation(mProgram, "aPosition");
            checkGlError("glGetAttribLocation aPosition");
            if (maPositionHandle == -1) {
                throw new RuntimeException("Could not get attrib location for aPosition");
            }
            maTextureHandle = GLES20.glGetAttribLocation(mProgram, "aTextureCoord");
            checkGlError("glGetAttribLocation aTextureCoord");
            if (maTextureHandle == -1) {
                throw new RuntimeException("Could not get attrib location for aTextureCoord");
            }

            muMVPMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uMVPMatrix");
            checkGlError("glGetUniformLocation uMVPMatrix");
            if (muMVPMatrixHandle == -1) {
                throw new RuntimeException("Could not get attrib location for uMVPMatrix");
            }

            muSTMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uSTMatrix");
            checkGlError("glGetUniformLocation uSTMatrix");
            if (muSTMatrixHandle == -1) {
                throw new RuntimeException("Could not get attrib location for uSTMatrix");
            }


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

            mTextureID = textures[0];
            GLES20.glBindTexture(GL_TEXTURE_EXTERNAL_OES, mTextureID);
            checkGlError("glBindTexture mTextureID");

            GLES20.glTexParameterf(GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_MIN_FILTER,
                                   GLES20.GL_NEAREST);
            GLES20.glTexParameterf(GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_MAG_FILTER,
                                   GLES20.GL_LINEAR);

            mSurface = new SurfaceTexture(mTextureID);
                mSurface.setOnFrameAvailableListener(this);

                Surface surface = new Surface(mSurface);

                    mMediaPlayer.setSurface(surface);
                    mMediaPlayer.setScreenOnWhilePlaying(true);
                    surface.release();

                try {
                    mMediaPlayer.prepare();
                } catch (IOException t) {
                    Log.e(TAG, "media player prepare failed");

                    synchronized(this) {
                        updateSurface = false;
                    }           
                }

                mMediaPlayer.start();


        }

        synchronized public void onFrameAvailable(SurfaceTexture surface) {
            updateSurface = true;
        }

        private int loadShader(int shaderType, String source) {
            int shader = GLES20.glCreateShader(shaderType);
            if (shader != 0) {
                GLES20.glShaderSource(shader, source);
                GLES20.glCompileShader(shader);
                int[] compiled = new int[1];
                GLES20.glGetShaderiv(shader, GLES20.GL_COMPILE_STATUS, compiled, 0);
                if (compiled[0] == 0) {
                    Log.e(TAG, "Could not compile shader " + shaderType + ":");
                    Log.e(TAG, GLES20.glGetShaderInfoLog(shader));
                    GLES20.glDeleteShader(shader);
                    shader = 0;
                }
            }
            return shader;
        }

        private int createProgram(String vertexSource, String fragmentSource) {
            int vertexShader = loadShader(GLES20.GL_VERTEX_SHADER, vertexSource);
            if (vertexShader == 0) {
                return 0;
            }
            int pixelShader = loadShader(GLES20.GL_FRAGMENT_SHADER, fragmentSource);
            if (pixelShader == 0) {
                return 0;
            }

            int program = GLES20.glCreateProgram();
            if (program != 0) {
                GLES20.glAttachShader(program, vertexShader);
                checkGlError("glAttachShader");
                GLES20.glAttachShader(program, pixelShader);
                checkGlError("glAttachShader");
                GLES20.glLinkProgram(program);
                int[] linkStatus = new int[1];
                GLES20.glGetProgramiv(program, GLES20.GL_LINK_STATUS, linkStatus, 0);
                if (linkStatus[0] != GLES20.GL_TRUE) {
                    Log.e(TAG, "Could not link program: ");
                    Log.e(TAG, GLES20.glGetProgramInfoLog(program));
                    GLES20.glDeleteProgram(program);
                    program = 0;
                }
            }
            return program;
        }

        private void checkGlError(String op) {
            int error;
            while ((error = GLES20.glGetError()) != GLES20.GL_NO_ERROR) {
                Log.e(TAG, op + ": glError " + error);
                throw new RuntimeException(op + ": glError " + error);
            }
        }
}

https://db.tt/rDjbtYjE

我的问题是如何将视频设置为纹理并将视频纹理绑定在立方体上?

谢谢!

1 个答案:

答案 0 :(得分:1)

在OpenGL ES中使用视频比您预期的要复杂得多。关键问题是:

  1. 视频帧必须从YUV转换为RGB色彩空间。最好在2.0或3.0 GLSL着色器代码中或使用外部纹理完成。

  2. glTexImage2D()函数太慢,无法处理高清视频帧速率,因为它会复制数据。使用名为EGL_NATIVE_BUFFER_ANDROID的EGL图像扩展名。

  3. 视频帧的解码必须与OpenGL ES的纹理加载同步。这可以通过围栏同步扩展来完成。

  4. answer包含一些链接,其中包含可帮助您入门的更多信息。