Android MediaCodec 简明教程：使用 MediaCodec 解码到纹理，使用 OpenGL ES 进行处理，并编码为 MP4 文件

import android.graphics.SurfaceTexture;
import android.opengl.GLES11Ext;
import android.opengl.GLES20;
import android.opengl.Matrix;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
 
public class TextureRender {
    private static final String VERTEX_SHADER_CODE =
            "uniform mat4 uMVPMatrix;\n" +
            "attribute vec2 aPosition;\n" +
            "attribute vec2 aTextureCoord;\n" +
            "varying vec2 vTextureCoord;\n" +
            "void main() {\n" +
            "    vTextureCoord = aTextureCoord;\n" +
            "    gl_Position = uMVPMatrix * vec4(aPosition, 0.0, 1.0);\n" +
            "}\n";
 
    private static final String FRAGMENT_SHADER_CODE =
            "#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 final float[] mMVPMatrix = new float[16];
    private final float[] mSTMatrix = new float[16];
 
    private int mProgram;
    private int mTextureID = -12;
    private int muMVPMatrixHandle;
    private int maPositionHandle;
    private int maTextureHandle;
    private int muSTMatrixHandle;
 
    public TextureRender() {
        // 加载定点着色器和片段着色器
        int vertexShader = loadShader(GLES20.GL_VERTEX_SHADER, VERTEX_SHADER_CODE);
        int fragmentShader = loadShader(GLES20.GL_FRAGMENT_SHADER, FRAGMENT_SHADER_CODE);
 
        // 创建程序
        mProgram = GLES20.glCreateProgram();
        GLES20.glAttachShader(mProgram, vertexShader);
        GLES20.glAttachShader(mProgram, fragmentShader);
        GLES20.glLinkProgram(mProgram);
    }
 
    public void drawFrame(SurfaceTexture st) {
        // 使用程序
        GLES20.glUseProgram(mProgram);
 
        // 获取变换矩阵处理句柄
        muMVPMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uMVPMatrix");
        maPositionHandle = GLES20.glGetAttribLocation(mProgram, "aPosition");
        maTextureHandle = GLES20.glGetAttribLocation(mProgram, "aTextureCoord");
        muSTMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uSTMatrix");
 
        // 获取外部纹理
        if (mTextureID == -12) {
            int[] textures = new int[1];
            GLES20.glGenTextures(1, textur