mirror of
https://github.com/mpv-player/mpv
synced 2024-12-15 03:15:52 +00:00
d97d29a54f
git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@7520 b3059339-0415-0410-9bf9-f77b7e298cf2
130 lines
3.6 KiB
C
130 lines
3.6 KiB
C
/* ------------------------------------------------------------------------
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* Creative YUV Video Decoder
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*
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* Dr. Tim Ferguson, 2001.
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* For more details on the algorithm:
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* http://www.csse.monash.edu.au/~timf/videocodec.html
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*
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* Code restructured, and adopted to MPlayer's mpi by A'rpi, 2002.
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*
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* This is a very simple predictive coder. A video frame is coded in YUV411
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* format. The first pixel of each scanline is coded using the upper four
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* bits of its absolute value. Subsequent pixels for the scanline are coded
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* using the difference between the last pixel and the current pixel (DPCM).
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* The DPCM values are coded using a 16 entry table found at the start of the
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* frame. Thus four bits per component are used and are as follows:
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* UY VY YY UY VY YY UY VY...
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* ------------------------------------------------------------------------ */
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#include <stdio.h>
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#include <stdlib.h>
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#include "config.h"
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#include "mp_msg.h"
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#include "vd_internal.h"
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static vd_info_t info = {
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"Creative YUV decoder",
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"cyuv",
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"A'rpi",
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"Dr. Tim Ferguson",
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"native codec"
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};
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LIBVD_EXTERN(cyuv)
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// to set/get/query special features/parameters
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static int control(sh_video_t *sh,int cmd,void* arg,...){
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return CONTROL_UNKNOWN;
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}
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// init driver
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static int init(sh_video_t *sh){
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return mpcodecs_config_vo(sh,sh->disp_w,sh->disp_h,IMGFMT_411P);
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}
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// uninit driver
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static void uninit(sh_video_t *sh){
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}
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// decode a frame
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static mp_image_t* decode(sh_video_t *sh,void* data,int len,int flags){
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mp_image_t* mpi;
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unsigned int xpos, ypos;
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unsigned char *delta_y_tbl = ((unsigned char*)data)+16;
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unsigned char *delta_c_tbl = ((unsigned char*)data)+32;
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unsigned char *ptr = ((unsigned char*)data)+48;
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if(len<=48) return NULL; // skipped/broken frame
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mpi=mpcodecs_get_image(sh, MP_IMGTYPE_TEMP, MP_IMGFLAG_ACCEPT_STRIDE,
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sh->disp_w, sh->disp_h);
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if(!mpi) return NULL;
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for(ypos = 0; ypos < mpi->h; ypos++){
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unsigned int i;
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unsigned char cur_Y1,cur_Y2,cur_U,cur_V;
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unsigned char *frame=mpi->planes[0]+mpi->stride[0]*ypos;
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unsigned char *uframe=mpi->planes[1]+mpi->stride[1]*ypos;
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unsigned char *vframe=mpi->planes[2]+mpi->stride[2]*ypos;
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for(xpos = 0; xpos < mpi->w; xpos += 2){
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if(xpos&2){
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i = *(ptr++);
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cur_Y1 = (cur_Y2 + delta_y_tbl[i & 0x0f])/* & 0xff*/;
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cur_Y2 = (cur_Y1 + delta_y_tbl[i >> 4])/* & 0xff*/;
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} else {
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if(xpos == 0) { /* first pixels in scanline */
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cur_U = *(ptr++);
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cur_Y1= (cur_U & 0x0f) << 4;
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cur_U = cur_U & 0xf0;
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cur_V = *(ptr++);
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cur_Y2= (cur_Y1 + delta_y_tbl[cur_V & 0x0f])/* & 0xff*/;
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cur_V = cur_V & 0xf0;
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} else { /* subsequent pixels in scanline */
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i = *(ptr++);
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cur_U = (cur_U + delta_c_tbl[i >> 4])/* & 0xff*/;
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cur_Y1= (cur_Y2 + delta_y_tbl[i & 0x0f])/* & 0xff*/;
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i = *(ptr++);
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cur_V = (cur_V + delta_c_tbl[i >> 4])/* & 0xff*/;
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cur_Y2= (cur_Y1 + delta_y_tbl[i & 0x0f])/* & 0xff*/;
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}
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}
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// ok, store the pixels:
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switch(mpi->imgfmt){
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case IMGFMT_YUY2:
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*frame++ = cur_Y1;
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*frame++ = cur_U;
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*frame++ = cur_Y2;
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*frame++ = cur_V;
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break;
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case IMGFMT_UYVY:
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*frame++ = cur_U;
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*frame++ = cur_Y1;
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*frame++ = cur_V;
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*frame++ = cur_Y2;
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break;
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case IMGFMT_422P:
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*uframe++ = cur_U;
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*vframe++ = cur_V;
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*frame++ = cur_Y1;
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*frame++ = cur_Y2;
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break;
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case IMGFMT_411P:
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if(!(xpos&2)){
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*uframe++ = cur_U;
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*vframe++ = cur_V;
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}
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*frame++ = cur_Y1;
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*frame++ = cur_Y2;
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break;
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}
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} // xpos
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} // ypos
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return mpi;
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}
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