Android-如何使用opengl-es在3D立方体上渲染视频纹理？

Question

I draw a 3D cube by using opengl-es

https://db.tt/ktcbwtnD //this is the picture, because I'm new in stackoverflow so i cant paste picture

and I also renderer video by reference this code

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

My problem is how to set video as a texture and bind video texture on cube ?

Thank You!

Answer 1

Using video with OpenGL ES is more complex than you probably expect. The key issues are:

1. Video frames must be converted from YUV to RGB color space. This is best done in 2.0 or 3.0 GLSL shader code or using external textures.

2. The glTexImage2D() function is too slow to handle HD video frame rates because it copies the data. Use the EGL Image Extension instead named EGL_NATIVE_BUFFER_ANDROID.

3. The decoding of video frames must be synchronized with OpenGL ES's texture loading. This can be done with the fence sync extensions.

This answer has some links with further information to get you started.