处理AVFrame使存储的YUV旋转（YUV420P，旋转90的倍数）

1、原理介绍

以YUV420P为例，AVFrame结构体存储YUV为data[0]存储Y，data[1]存储U，data[2]存储V，按一行一行的顺序存储，知道如何存储后，要旋转90的倍数就简单了。

2、代码

旋转90：

for (int i = 0; i < m_srcW; i++)
		{
			for (int j = 0; j < m_srcH; j++)
			{
				m_FrameConverRotate->data[0][i * m_FrameConverRotate->linesize[0] + j] = 
					tmpFrameSrcYUV->data[0][(m_srcH - j - 1) * tmpFrameSrcYUV->linesize[0] + i];
			}
		}

		//UV
		for (int i = 0; i < m_srcW / 2; i++)
		{
			for (int j = 0; j < m_srcH / 2; j++)
			{
				m_FrameConverRotate->data[1][i * m_FrameConverRotate->linesize[1] + j] = 
					tmpFrameSrcYUV->data[1][(m_srcH / 2 - j - 1) * tmpFrameSrcYUV->linesize[1] + i];

				m_FrameConverRotate->data[2][i * m_FrameConverRotate->linesize[2] + j] = 
					tmpFrameSrcYUV->data[2][(m_srcH / 2 - j - 1) * tmpFrameSrcYUV->linesize[2] + i];
			}
		}

旋转270：

for (int i = 0; i < m_srcW; i++)
		{
			for (int j = 0; j < m_srcH; j++)
			{
				m_FrameConverRotate->data[0][i * m_FrameConverRotate->linesize[0] + j] = 
					tmpFrameSrcYUV->data[0][j * tmpFrameSrcYUV->linesize[0] + (tmpFrameSrcYUV->linesize[0] - i - 1)];
			}
		}

		for (int i = 0; i < m_srcW / 2; i++)
		{
			for (int j = 0; j < m_srcH / 2; j++)
			{
				m_FrameConverRotate->data[1][i * m_FrameConverRotate->linesize[1] + j] = 
					tmpFrameSrcYUV->data[1][j * tmpFrameSrcYUV->linesize[1] + (tmpFrameSrcYUV->linesize[1] - i - 1)];

				m_FrameConverRotate->data[2][i * m_FrameConverRotate->linesize[2] + j] = 
					tmpFrameSrcYUV->data[2][j * tmpFrameSrcYUV->linesize[2] + (tmpFrameSrcYUV->linesize[2] - i - 1)];
			}
		}

180度上下颠倒即可，在此就不做示例了。