使用矩阵rotateM（）从表面纹理，但腐败的视频输出旋转矩阵 [英] Use rotateM() of Matrix to rotate matrix from SurfaceTexture but corrupt the video output

问题描述

我设法与OpenGL ES的播放视频，我用grafika的ContinuousCaptureActivity的方式，我的数据源是MediaPlayer的，而不是相机，这没什么区别。
MediaPlayer的不断产生视频帧和我绘制onFrameAvailable回调每一帧屏幕。在code是如下效果很好：

I managed to play video with opengl es, I used the way of grafika's ContinuousCaptureActivity, my data source is MediaPlayer rather than Camera which makes no difference. MediaPlayer produces video frames continuously and I draw each frame to screen in onFrameAvailable callback. The code is as follows which works well:

    mVideoTexture.updateTexImage();
    mVideoTexture.getTransformMatrix(mTmpMatrix);
    mDisplaySurface.makeCurrent();
    int viewWidth = getWidth();
    int viewHeight = getHeight();
    GLES20.glViewport(0, 0, viewWidth, viewHeight);
    mFullFrameBlit.drawFrame(mTextureId, mTmpMatrix);
    mDisplaySurface.swapBuffers();

现在我想用270度旋转的视频帧，所以我改变了code：

Now I want to rotate video frames with 270 degrees, so I changed the code:

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

    mVideoTexture.updateTexImage();
    mVideoTexture.getTransformMatrix(mTmpMatrix);
    mDisplaySurface.makeCurrent();
    int viewWidth = getWidth();
    int viewHeight = getHeight();
    GLES20.glViewport(0, 0, viewWidth, viewHeight);
    Matrix.rotateM(mTmpMatrix, 0, 270, 1f, 0, 0);
    mFullFrameBlit.drawFrame(mTextureId, mTmpMatrix);
    mDisplaySurface.swapBuffers();

但结果是怪异的，看看下面的图片：

不过，我可以与下面的code成功翻转视频帧：

But I can flip video frame successfully with the code below:

        mVideoTexture.updateTexImage();
    mVideoTexture.getTransformMatrix(mTmpMatrix);
    mDisplaySurface.makeCurrent();
    int viewWidth = getWidth();
    int viewHeight = getHeight();
    GLES20.glViewport(0, 0, viewWidth, viewHeight);
    mTmpMatrix[5] = -1 * mTmpMatrix[5];
    mTmpMatrix[13] = 1.0f - mTmpMatrix[13];
    mFullFrameBlit.drawFrame(mTextureId, mTmpMatrix);
    mDisplaySurface.swapBuffers();

如何实现旋转，任何人都可以给我一些帮助吗？

How to achieve the rotation, Could anyone give me some help?

地址：

首先，我想告诉大家，我一直用这个code为每次抽奖行动：

At first, I want to tell that I always used this code for each draw action:

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

我用这个演示做我的测试，这是本次测试的很好的演示。
https://github.com/izacus/AndroidOpenGLVideoDemo

该矩阵从得到表面纹理是：

The matrix got from the surfacetexture is:

1.0，0.0，0.0，0.0

1.0, 0.0, 0.0, 0.0

0.0，-1.0，0.0，0.0

0.0, -1.0, 0.0, 0.0

0.0，0.0，1.0，0.0

0.0, 0.0, 1.0, 0.0

0.0，1.0，0.0，1.0

0.0, 1.0, 0.0, 1.0

在Matrix.setRotateM（videoTextureTransform，0，270，0，0，1）;，

After "Matrix.setRotateM(videoTextureTransform, 0, 270 , 0, 0, 1);",

成为：

1.1924881E-8，-1.0，0.0，0.0

1.1924881E-8, -1.0, 0.0, 0.0

1.0，1.1924881E-8，0.0，0.0

1.0, 1.1924881E-8, 0.0, 0.0

0.0，0.0，1.0，0.0

0.0, 0.0, 1.0, 0.0

0.0，0.0，0.0，1.0

0.0, 0.0, 0.0, 1.0

和视频效果是：

推荐答案

需要法登的绕z轴的旋转矩阵所应遵循的正确翻译，使其回到屏幕上，可以这么说。我测试下的所有3个旋转的视频表面纹理：

fadden's rotation matrix about the z-axis needs to be followed by the correct translation to bring it back on-screen, so to speak. I've tested all 3 rotations below on SurfaceTexture video:

旋转90度

Matrix.rotateM(mTmpMatrix, 0, 90, 0, 0, 1);
Matrix.translateM(mTmpMatrix, 0, 0, -1, 0);

旋转180

Matrix.rotateM(mTmpMatrix, 0, 180, 0, 0, 1);
Matrix.translateM(mTmpMatrix, 0, -1, -1, 0);

旋转270

Matrix.rotateM(mTmpMatrix, 0, 270, 0, 0, 1);
Matrix.translateM(mTmpMatrix, 0, -1, 0, 0);

这篇关于使用矩阵rotateM（）从表面纹理，但腐败的视频输出旋转矩阵的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！