YUV420P,Y,U,V三个分量都是平面格式,分为I420和YV12。I420格式和YV12格式的不同处在U平面和V平面的位置不同。在I420格式中,U平面紧跟在Y平面之后,然后才是V平面(即:YUV);但YV12则是相反(即:YVU)。
YUV420SP, Y分量平面格式,UV打包格式, 即NV12。 NV12与NV21类似,U 和 V 交错排列,不同在于UV顺序。
I420: YYYYYYYY UU VV =>YUV420P
YV12: YYYYYYYY VV UU =>YUV420P
NV12: YYYYYYYY UVUV =>YUV420SP
NV21: YYYYYYYY VUVU =>YUV420SP
1、NV21转nv12
private void
swapNV21ToNV12(byte[]
nv21,byte[] nv12,int
width,int
height){
if(nv21
== null
|| nv12 ==
null)return;
int
framesize = width*height;
int
i =
0,j =
0;
System.arraycopy(nv21,
0, nv12,
0, framesize);
for
(j =
0; j < framesize/2;
j+=2)
{
nv12[framesize + j +
1] = nv21[j + framesize];
}
for
(j =
0; j < framesize/2;
j += 2)
{
nv12[framesize + j] = nv21[j + framesize +
1];
}
}
2、YV12转I420
private void
swapYV12toI420(byte[]
yv12bytes, byte[] i420bytes,
int
width,
int
height)
{
System.arraycopy(yv12bytes,
0, i420bytes,
0,width*height);
System.arraycopy(yv12bytes,
width*height+width*height/4,
i420bytes, width*height,width*height/4);
System.arraycopy(yv12bytes,
width*height, i420bytes,
width*height+width*height/4,width*height/4);
}
3、yv12转nv12
void
swapYV12toNV12(byte[]
yv12bytes, byte[] nv12bytes,
int
width,int
height)
{
int
nLenY = width * height;
int
nLenU = nLenY /
4;
System.arraycopy(yv12bytes,
0, nv12bytes,
0, width * height);
for
(int
i =
0; i < nLenU; i++) {
nv12bytes[nLenY +
2
* i + 1] = yv12bytes[nLenY + i];
nv12bytes[nLenY +
2
* i] = yv12bytes[nLenY + nLenU + i];
}
}
4、nv12转I420
void swapNV12toI420(byte[] nv12bytes, byte[] i420bytes, int width,int height)
{
int nLenY = width * height;
int nLenU = nLenY / 4;
System.arraycopy(nv12bytes, 0, i420bytes, 0, width * height);
for (int i = 0; i < nLenU; i++) {
i420bytes[nLenY + i] = nv12bytes[nLenY + 2 * i + 1];
i420bytes[nLenY + nLenU + i] = nv12bytes[nLenY + 2 * i];
}