mirror of https://github.com/mpv-player/mpv
130 lines
3.6 KiB
C
130 lines
3.6 KiB
C
/* ------------------------------------------------------------------------
|
|
* Creative YUV Video Decoder
|
|
*
|
|
* Dr. Tim Ferguson, 2001.
|
|
* For more details on the algorithm:
|
|
* http://www.csse.monash.edu.au/~timf/videocodec.html
|
|
*
|
|
* Code restructured, and adopted to MPlayer's mpi by A'rpi, 2002.
|
|
*
|
|
* This is a very simple predictive coder. A video frame is coded in YUV411
|
|
* format. The first pixel of each scanline is coded using the upper four
|
|
* bits of its absolute value. Subsequent pixels for the scanline are coded
|
|
* using the difference between the last pixel and the current pixel (DPCM).
|
|
* The DPCM values are coded using a 16 entry table found at the start of the
|
|
* frame. Thus four bits per component are used and are as follows:
|
|
* UY VY YY UY VY YY UY VY...
|
|
* ------------------------------------------------------------------------ */
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
|
|
#include "config.h"
|
|
#include "mp_msg.h"
|
|
|
|
#include "vd_internal.h"
|
|
|
|
static vd_info_t info = {
|
|
"Creative YUV decoder",
|
|
"cyuv",
|
|
"A'rpi",
|
|
"Dr. Tim Ferguson",
|
|
"native codec"
|
|
};
|
|
|
|
LIBVD_EXTERN(cyuv)
|
|
|
|
// to set/get/query special features/parameters
|
|
static int control(sh_video_t *sh,int cmd,void* arg,...){
|
|
return CONTROL_UNKNOWN;
|
|
}
|
|
|
|
// init driver
|
|
static int init(sh_video_t *sh){
|
|
return mpcodecs_config_vo(sh,sh->disp_w,sh->disp_h,IMGFMT_411P);
|
|
}
|
|
|
|
// uninit driver
|
|
static void uninit(sh_video_t *sh){
|
|
}
|
|
|
|
// decode a frame
|
|
static mp_image_t* decode(sh_video_t *sh,void* data,int len,int flags){
|
|
mp_image_t* mpi;
|
|
unsigned int xpos, ypos;
|
|
unsigned char *delta_y_tbl = ((unsigned char*)data)+16;
|
|
unsigned char *delta_c_tbl = ((unsigned char*)data)+32;
|
|
unsigned char *ptr = ((unsigned char*)data)+48;
|
|
|
|
if(len<=48) return NULL; // skipped/broken frame
|
|
|
|
mpi=mpcodecs_get_image(sh, MP_IMGTYPE_TEMP, MP_IMGFLAG_ACCEPT_STRIDE,
|
|
sh->disp_w, sh->disp_h);
|
|
if(!mpi) return NULL;
|
|
|
|
for(ypos = 0; ypos < mpi->h; ypos++){
|
|
unsigned int i;
|
|
unsigned char cur_Y1,cur_Y2,cur_U,cur_V;
|
|
unsigned char *frame=mpi->planes[0]+mpi->stride[0]*ypos;
|
|
unsigned char *uframe=mpi->planes[1]+mpi->stride[1]*ypos;
|
|
unsigned char *vframe=mpi->planes[2]+mpi->stride[2]*ypos;
|
|
|
|
for(xpos = 0; xpos < mpi->w; xpos += 2){
|
|
|
|
if(xpos&2){
|
|
i = *(ptr++);
|
|
cur_Y1 = (cur_Y2 + delta_y_tbl[i & 0x0f])/* & 0xff*/;
|
|
cur_Y2 = (cur_Y1 + delta_y_tbl[i >> 4])/* & 0xff*/;
|
|
} else {
|
|
if(xpos == 0) { /* first pixels in scanline */
|
|
cur_U = *(ptr++);
|
|
cur_Y1= (cur_U & 0x0f) << 4;
|
|
cur_U = cur_U & 0xf0;
|
|
cur_V = *(ptr++);
|
|
cur_Y2= (cur_Y1 + delta_y_tbl[cur_V & 0x0f])/* & 0xff*/;
|
|
cur_V = cur_V & 0xf0;
|
|
} else { /* subsequent pixels in scanline */
|
|
i = *(ptr++);
|
|
cur_U = (cur_U + delta_c_tbl[i >> 4])/* & 0xff*/;
|
|
cur_Y1= (cur_Y2 + delta_y_tbl[i & 0x0f])/* & 0xff*/;
|
|
i = *(ptr++);
|
|
cur_V = (cur_V + delta_c_tbl[i >> 4])/* & 0xff*/;
|
|
cur_Y2= (cur_Y1 + delta_y_tbl[i & 0x0f])/* & 0xff*/;
|
|
}
|
|
}
|
|
|
|
// ok, store the pixels:
|
|
switch(mpi->imgfmt){
|
|
case IMGFMT_YUY2:
|
|
*frame++ = cur_Y1;
|
|
*frame++ = cur_U;
|
|
*frame++ = cur_Y2;
|
|
*frame++ = cur_V;
|
|
break;
|
|
case IMGFMT_UYVY:
|
|
*frame++ = cur_U;
|
|
*frame++ = cur_Y1;
|
|
*frame++ = cur_V;
|
|
*frame++ = cur_Y2;
|
|
break;
|
|
case IMGFMT_422P:
|
|
*uframe++ = cur_U;
|
|
*vframe++ = cur_V;
|
|
*frame++ = cur_Y1;
|
|
*frame++ = cur_Y2;
|
|
break;
|
|
case IMGFMT_411P:
|
|
if(!(xpos&2)){
|
|
*uframe++ = cur_U;
|
|
*vframe++ = cur_V;
|
|
}
|
|
*frame++ = cur_Y1;
|
|
*frame++ = cur_Y2;
|
|
break;
|
|
}
|
|
} // xpos
|
|
} // ypos
|
|
|
|
return mpi;
|
|
}
|