libmpcodecs/vd_mpng.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3
   4 #include "config.h"
   5 #include "mp_msg.h"
   6
   7 #include <png.h>
   8
   9 #include "libavutil/common.h"
  10 #include "mpbswap.h"
  11 #include "libvo/fastmemcpy.h"
  12
  13 #include "vd_internal.h"
  14
  15 static vd_info_t info = {
  16         "PNG Images decoder",
  17         "mpng",
  18         "A'rpi",
  19         ".so, based on mpng.c",
  20         "uses libpng, 8bpp modes not supported yet"
  21 };
  22
  23 LIBVD_EXTERN(mpng)
  24
  25 static unsigned int out_fmt=0;
  26
  27 static int last_w=-1;
  28 static int last_h=-1;
  29 static int last_c=-1;
  30
  31 // to set/get/query special features/parameters
  32 static int control(sh_video_t *sh,int cmd,void* arg,...){
  33     switch (cmd)
  34     {
  35         case VDCTRL_QUERY_FORMAT:
  36             if (*((int *) arg) == out_fmt) return CONTROL_TRUE;
  37             return CONTROL_FALSE;
  38     }
  39     return CONTROL_UNKNOWN;
  40 }
  41
  42 // init driver
  43 static int init(sh_video_t *sh){
  44     last_w=-1;
  45     return 1;
  46 }
  47
  48 // uninit driver
  49 static void uninit(sh_video_t *sh){
  50 }
  51
  52 //mp_image_t* mpcodecs_get_image(sh_video_t *sh, int mp_imgtype, int mp_imgflag, int w, int h);
  53
  54 static int    pngPointer;
  55 static int    pngLength;
  56
  57 static void pngReadFN( png_structp pngstr,png_bytep buffer,png_size_t size )
  58 {
  59  char * p = pngstr->io_ptr;
  60  if(size>pngLength-pngPointer && pngLength>=pngPointer) size=pngLength-pngPointer;
  61  fast_memcpy( buffer,(char *)&p[pngPointer],size );
  62  pngPointer+=size;
  63 }
  64
  65 // decode a frame
  66 static mp_image_t* decode(sh_video_t *sh,void* data,int len,int flags){
  67     png_structp     png;
  68     png_infop       info;
  69     png_infop       endinfo;
  70 //    png_bytep       data;
  71     png_bytep     * row_p;
  72     png_uint_32     png_width=0,png_height=0;
  73     int             depth,color;
  74     png_uint_32     i;
  75     mp_image_t* mpi;
  76
  77     int cols;
  78     png_colorp pal;
  79     unsigned char *p;
  80
  81     if(len<=0) return NULL; // skipped frame
  82
  83  png=png_create_read_struct( PNG_LIBPNG_VER_STRING,NULL,NULL,NULL );
  84  info=png_create_info_struct( png );
  85  endinfo=png_create_info_struct( png );
  86
  87  pngPointer=8;
  88  pngLength=len;
  89  png_set_read_fn( png,data,pngReadFN );
  90  png_set_strip_16( png );
  91  png_set_sig_bytes( png,8 );
  92  png_read_info( png,info );
  93  png_get_IHDR( png,info,&png_width,&png_height,&depth,&color,NULL,NULL,NULL );
  94  png_set_bgr( png );
  95
  96  switch( info->color_type ) {
  97    case PNG_COLOR_TYPE_GRAY_ALPHA:
  98       mp_msg( MSGT_DECVIDEO,MSGL_INFO,"Sorry gray scaled png with alpha channel not supported at moment.\n" );
  99       break;
 100    case PNG_COLOR_TYPE_GRAY:
 101       out_fmt=IMGFMT_Y800;
 102       break;
 103    case PNG_COLOR_TYPE_PALETTE:
 104       out_fmt=IMGFMT_BGR8;
 105       break;
 106    case PNG_COLOR_TYPE_RGB_ALPHA:
 107       out_fmt=IMGFMT_BGR32;
 108       break;
 109    case PNG_COLOR_TYPE_RGB:
 110       out_fmt=IMGFMT_BGR24;
 111       break;
 112    default:
 113       mp_msg( MSGT_DECVIDEO,MSGL_INFO,"Sorry, unsupported PNG colorspace: %d.\n" ,info->color_type);
 114  }
 115
 116  // (re)init libvo if image parameters changed (width/height/colorspace)
 117  if(last_w!=png_width || last_h!=png_height || last_c!=out_fmt){
 118     last_w=png_width; last_h=png_height; last_c=out_fmt;
 119     if(!out_fmt) return NULL;
 120     if(!mpcodecs_config_vo(sh,png_width,png_height,out_fmt)) return NULL;
 121  }
 122
 123 #if 0
 124  switch( info->color_type )
 125   {
 126    case PNG_COLOR_TYPE_GRAY_ALPHA: printf( "[png] used GrayA -> stripping alpha channel\n" ); break;
 127    case PNG_COLOR_TYPE_GRAY:       printf( "[png] used Gray -> rgb\n" ); break;
 128    case PNG_COLOR_TYPE_PALETTE:    printf( "[png] used palette -> rgb\n" ); break;
 129    case PNG_COLOR_TYPE_RGB_ALPHA:  printf( "[png] used RGBA -> stripping alpha channel\n" ); break;
 130    case PNG_COLOR_TYPE_RGB:        printf( "[png] read rgb datas.\n" ); break;
 131   }
 132 #endif
 133
 134     mpi=mpcodecs_get_image(sh, MP_IMGTYPE_TEMP, MP_IMGFLAG_ACCEPT_STRIDE,
 135         png_width,png_height);
 136     if(!mpi) return NULL;
 137
 138 // Let's DECODE!
 139  row_p=malloc( sizeof( png_bytep ) * png_height );
 140 //png_get_rowbytes( png,info )
 141  for ( i=0; i < png_height; i++ ) row_p[i]=mpi->planes[0] + mpi->stride[0]*i;
 142  png_read_image( png,row_p );
 143  free( row_p );
 144
 145  if (out_fmt==IMGFMT_BGR8) {
 146      png_get_PLTE( png,info,&pal,&cols );
 147      mpi->planes[1] = (char*)realloc(mpi->planes[1], 4*cols);
 148      p = mpi->planes[1];
 149      for (i = 0; i < cols; i++) {
 150          *p++ = pal[i].blue;
 151          *p++ = pal[i].green;
 152          *p++ = pal[i].red;
 153          *p++ = 0;
 154      }
 155  }
 156
 157  png_read_end( png,endinfo );
 158  png_destroy_read_struct( &png,&info,&endinfo );
 159
 160     return mpi;
 161 }