Avframe data to RGB or YUV

Using FFMEPG decoding video is generally generated avframe. Then convert to RGB or YUV. Have never understood the conversion relationship between them. It's actually very simple:

Avframe Turn RGB:

Avframe---> RGB

DATA[0]---RGG data

LINESIZE[0]----width*pixel_size for RGB

Avframe Transfer to YUV:

Avframe--->YUV

DATA[0]----Y data[1]----U
DATA[2]----V

Linesize[0] Length of------Y

LINESIZE[1] (LINESIZE[0]/2)------The length of U or V.

Code:

-(UIImage *) Convertframetorgb: (float) with height: (float) Height {

/* Float with = pcodecctx->width;

float height = pcodecctx->height;*/

if (Pframe->data[0]) {

struct Swscontext * scxt =sws_getcontext (With,height,pix_fmt_yuv420p,with,height,pix_fmt_rgba,sws_point,null,null, NULL);

if (scxt = = NULL) {

return nil;

}

Avpicture_alloc (&picture,pix_fmt_rgba, with, height);

Sws_scale (SCXT, (const uint8_t * *) Pframe->data, pframe->linesize, 0,height,picture.data, picture.linesize);

Cgbitmapinfo Bitmapinfo =kcgbitmapbyteorderdefault;

Cfdataref data = Cfdatacreatewithbytesnocopy (Kcfallocatordefault,picture.data[0],picture.linesize[0]*height, Kcfallocatornull);

Cgdataproviderref provider =cgdataprovidercreatewithcfdata (data);

Cgcolorspaceref colorspace =cgcolorspacecreatedevicergb ();

Cgimageref cgimage = cgimagecreate (With,height,

8,24,picture.linesize[0],

Colorspace,bitmapinfo,provider,null,no,kcgrenderingintentdefault);

Cgcolorspacerelease (ColorSpace);

UIImage *image = [Uiimageimagewithcgimage:cgimage];

Cgimagerelease (Cgimage);

Cgdataproviderrelease (provider);

Cfrelease (data);

return image;

}

return nil;

}

-(NSData *) Framedatatoyuvdata: (UInt8 *) data Size: (int) linesize width: (int) Width height: (int) Height {

if (Linesize < width) {

width = linesize;

}

Nsmutabledata *tempdata = [nsmutabledatadatawithlength:width * height];

Byte *dstdata = tempdata.mutablebytes;

For (Nsuinteger i =0; i < height; ++i) {

memcpy (dstdata, data, width);

Dstdata + = width;

Data + = Linesize;

}

return tempdata;

}

-(void) Convertframetoyuv: (float) with height: (float) Height {

NSData *luma = [Selfframedatatoyuvdata:pframe->data[0]

SIZE:PFRAME->LINESIZE[0]

Width:with

Height:height];

NSData *CHROMA1 = [Selfframedatatoyuvdata:pframe->data[1]

SIZE:PFRAME->LINESIZE[1]

Width:with/2

HEIGHT:HEIGHT/2];

NSData *CHROMA2 = [Selfframedatatoyuvdata:pframe->data[2]

SIZE:PFRAME->LINESIZE[2]

Width:with/2

HEIGHT:HEIGHT/2];

}