java - OpenGL ES 2 (Android) 绘制位图

Question

我正在尝试使用解码 mp4 视频的代码添加位图(在 x、y 位置)并进行编码。

我正在尝试使用 Android OpenGL 代码 ( ExtractDecodeEditEncodeMuxTest.java ) 解码 mp4 视频并在每一帧(在特定的 x,y 位置)添加图像，最后将视频重新编码为 mp4。

我在创建表面时加载位图，并在 drawFrame 函数中尝试绘制位图，但只有视频帧(没有位图)被编码，为什么？

我尝试编辑 TextureRender这样

package com.test.decodeeditencode;

import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.SurfaceTexture;
import android.opengl.GLES11Ext;
import android.opengl.GLES20;
import android.opengl.GLUtils;
import android.opengl.Matrix;
import android.util.Log;
/**
 * Code for rendering a texture onto a surface using OpenGL ES 2.0.
 */
class TextureRender {
    private static final String TAG = "TextureRender";
    private static final int FLOAT_SIZE_BYTES = 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 final float[] mTriangleVerticesData = {
            // X, Y, Z, U, V
            -1.0f, -1.0f, 0, 0.f, 0.f,
            1.0f, -1.0f, 0, 1.f, 0.f,
            -1.0f,  1.0f, 0, 0.f, 1.f,
            1.0f,  1.0f, 0, 1.f, 1.f,
    };

    private final FloatBuffer mTexVertices;
    private final FloatBuffer mPosVertices;

    private final FloatBuffer mTriangleVertices;

    private static final String VERTEX_SHADER =
            "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 static final String FRAGMENT_SHADER =
            "#extension GL_OES_EGL_image_external : require\n" +
                    "precision mediump float;\n" +      // highp here doesn't seem to matter
                    "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 = -12345;
    private int mLogoTextureID;

    private int muMVPMatrixHandle;
    private int muSTMatrixHandle;
    private int maPositionHandle;
    private int maTextureHandle;

    private final Context mContext;

     public TextureRender(Context context) {
        mContext = context;

        mTriangleVertices = ByteBuffer.allocateDirect(mTriangleVerticesData.length * FLOAT_SIZE_BYTES).order(ByteOrder.nativeOrder()).asFloatBuffer();
        mTriangleVertices.put(mTriangleVerticesData).position(0);
        Matrix.setIdentityM(mSTMatrix, 0);
    }

    public int getTextureId() {
        return mTextureID;
    }

    public void drawFrame(SurfaceTexture st) {
        checkGlError("onDrawFrame start");

        st.getTransformMatrix(mSTMatrix);

        GLES20.glClearColor(0.0f, 1.0f, 0.0f, 1.0f);
        GLES20.glClear(GLES20.GL_DEPTH_BUFFER_BIT | GLES20.GL_COLOR_BUFFER_BIT);

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

        GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
        GLES20.glBindTexture(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, mTextureID);

        //***********DRAW BITMAP************
        GLES20.glActiveTexture(GLES20.GL_TEXTURE1);
        checkGlError("glActiveTexture");
        GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, mLogoTextureID);
        checkGlError("glBindTexture");
        GLES20.glUniform1i(maTextureHandle, 0);

        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, 2, GLES20.GL_FLOAT, false, TRIANGLE_VERTICES_DATA_STRIDE_BYTES, mTriangleVertices);
        checkGlError("glVertexAttribPointer maTextureHandle");

        GLES20.glEnableVertexAttribArray(maTextureHandle);
        checkGlError("glEnableVertexAttribArray maTextureHandle");

        Matrix.setIdentityM(mMVPMatrix, 0);
        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();
    }
    /**
     * Initializes GL state.  Call this after the EGL surface has been created and made current.
     */
    public void surfaceCreated() {
        mProgram = createProgram(VERTEX_SHADER, FRAGMENT_SHADER);

        if (mProgram == 0) {
            throw new RuntimeException("failed creating program");
        }

        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[2];

        GLES20.glGenTextures(2, textures, 0);
        mTextureID = textures[0];

        GLES20.glBindTexture(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, mTextureID);
        checkGlError("glBindTexture mTextureID");

        GLES20.glTexParameterf(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_NEAREST);
        GLES20.glTexParameterf(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_LINEAR);
        GLES20.glTexParameteri(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_WRAP_S, GLES20.GL_CLAMP_TO_EDGE);
        GLES20.glTexParameteri(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_WRAP_T, GLES20.GL_CLAMP_TO_EDGE);
        checkGlError("glTexParameter");

        mLogoTextureID = textures[1];

        //*******************Load input bitmap*************
        Bitmap bitmap = BitmapFactory.decodeResource(mContext.getResources(), R.drawable.google);

        // Upload to texture
        GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, mLogoTextureID);
        GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, bitmap, 0);

        bitmap.recycle();
    }
    /**
     * Replaces the fragment shader.
     */
    public void changeFragmentShader(String fragmentShader) {
        GLES20.glDeleteProgram(mProgram);
        mProgram = createProgram(VERTEX_SHADER, fragmentShader);

        if (mProgram == 0) {
            throw new RuntimeException("failed creating program");
        }
    }

    private int loadShader(int shaderType, String source) {

        int shader = GLES20.glCreateShader(shaderType);
        checkGlError("glCreateShader type=" + shaderType);

        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();
        checkGlError("glCreateProgram");

        if (program == 0) {
            Log.e(TAG, "Could not create program");
        }

        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;

    }

    public 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);
        }
    }
}

但是位图没有显示，

Answer 1

顶点属性 aPosition 和 aTexture 声明为 vec4 但您只提供 vec3 和 vec2:

GLES20.glVertexAttribPointer(maPositionHandle, 3, GLES20.GL_FLOAT, false, TRIANGLE_VERTICES_DATA_STRIDE_BYTES, mTriangleVertices);
GLES20.glVertexAttribPointer(maTextureHandle, 2, GLES20.GL_FLOAT, false, TRIANGLE_VERTICES_DATA_STRIDE_BYTES, mTriangleVertices);

您应该将您的 VS 代码更改为:

private static final String VERTEX_SHADER =
        "uniform mat4 uMVPMatrix;\n" +
        "uniform mat4 uSTMatrix;\n" +
        "attribute vec3 aPosition;\n" +
        "attribute vec2 aTextureCoord;\n" +
        "varying vec2 vTextureCoord;\n" +
        "void main() {\n" +
        "  gl_Position = uMVPMatrix * vec4(aPosition, 1.0);\n" +
        "  vTextureCoord = (uSTMatrix * vec4(aTextureCoord, 0.0, 1.0)).xy;\n" +
        "}\n";