使用 Matrix 的 rotateM() 从 SurfaceTexture 旋转矩阵但损坏视频输出 [英] Use rotateM() of Matrix to rotate matrix from SurfaceTexture but corrupt the video output

问题描述

我设法用opengl es播放视频，我使用了grafika的ContinuousCaptureActivity的方式，我的数据源是MediaPlayer而不是Camera，这没有什么区别.MediaPlayer 连续生成视频帧，我在 onFrameAvailable 回调中将每一帧绘制到屏幕上.代码如下，效果很好:

 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();

现在我想将视频帧旋转 270 度，所以我更改了代码:

 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();

但是结果很奇怪，看下图:

但是我可以使用下面的代码成功翻转视频帧:

 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();

如何实现轮换，谁能帮帮我?

添加:

首先，我想说的是，我总是在每个绘制动作中使用这段代码:

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

我用这个demo来做我的测试，对于这个测试来说它是一个很好的demo.

解决方案

fadden 关于 z 轴的旋转矩阵需要跟随正确的平移才能将其重新显示在屏幕上，可以这么说.我已经在 SurfaceTexture 视频上测试了以下所有 3 个旋转:

旋转 90 度

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

旋转 180 度

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);

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();

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();

But the result is weird, take a look at the picture below:

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();

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

ADD:

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);

I use this demo to do my test, it is a very good demo for this test. https://github.com/izacus/AndroidOpenGLVideoDemo

The matrix got from the surfacetexture is:

1.0, 0.0, 0.0, 0.0

0.0, -1.0, 0.0, 0.0

0.0, 0.0, 1.0, 0.0

0.0, 1.0, 0.0, 1.0

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

it became:

1.1924881E-8, -1.0, 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, 0.0, 1.0

And this video effect is:

解决方案

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:

ROTATE 90

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

ROTATE 180

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

ROTATE 270

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

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