libmpcodecs/vd_mpng.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3
   4 #include "config.h"
   5 #include "mp_msg.h"
   6
   7 #ifdef HAVE_PNG
   8
   9 #include <png.h>
  10
  11 #include "bswap.h"
  12 #include "postproc/rgb2rgb.h"
  13 #include "libvo/fastmemcpy.h"
  14
  15 #include "vd_internal.h"
  16
  17 static vd_info_t info = {
  18         "PNG Images decoder",
  19         "mpng",
  20         "A'rpi",
  21         ".so, based on mpng.c",
  22         "uses libpng, 8bpp modes not supported yet"
  23 };
  24
  25 LIBVD_EXTERN(mpng)
  26
  27 static unsigned int out_fmt=0;
  28
  29 static int last_w=-1;
  30 static int last_h=-1;
  31 static int last_c=-1;
  32
  33 // to set/get/query special features/parameters
  34 static int control(sh_video_t *sh,int cmd,void* arg,...){
  35     switch (cmd)
  36     {
  37         case VDCTRL_QUERY_FORMAT:
  38             if (*((int *) arg) == out_fmt) return CONTROL_TRUE;
  39             return CONTROL_FALSE;
  40     }
  41     return CONTROL_UNKNOWN;
  42 }
  43
  44 // init driver
  45 static int init(sh_video_t *sh){
  46     last_w=-1;
  47     return 1;
  48 }
  49
  50 // uninit driver
  51 static void uninit(sh_video_t *sh){
  52 }
  53
  54 //mp_image_t* mpcodecs_get_image(sh_video_t *sh, int mp_imgtype, int mp_imgflag, int w, int h);
  55
  56 static int    pngPointer;
  57 static int    pngLength;
  58
  59 static void pngReadFN( png_structp pngstr,png_bytep buffer,png_size_t size )
  60 {
  61  char * p = pngstr->io_ptr;
  62  if(size>pngLength-pngPointer && pngLength>=pngPointer) size=pngLength-pngPointer;
  63  memcpy( buffer,(char *)&p[pngPointer],size );
  64  pngPointer+=size;
  65 }
  66
  67 // decode a frame
  68 static mp_image_t* decode(sh_video_t *sh,void* data,int len,int flags){
  69     png_structp     png;
  70     png_infop       info;
  71     png_infop       endinfo;
  72 //    png_bytep       data;
  73     png_bytep     * row_p;
  74     png_uint_32     png_width=0,png_height=0;
  75     int             depth,color;
  76     png_uint_32     i;
  77     mp_image_t* mpi;
  78
  79     int cols;
  80     png_colorp pal;
  81     unsigned char *p;
  82
  83     if(len<=0) return NULL; // skipped frame
  84
  85  png=png_create_read_struct( PNG_LIBPNG_VER_STRING,NULL,NULL,NULL );
  86  info=png_create_info_struct( png );
  87  endinfo=png_create_info_struct( png );
  88
  89  pngPointer=8;
  90  pngLength=len;
  91  png_set_read_fn( png,data,pngReadFN );
  92  png_set_strip_16( png );
  93  png_set_sig_bytes( png,8 );
  94  png_read_info( png,info );
  95  png_get_IHDR( png,info,&png_width,&png_height,&depth,&color,NULL,NULL,NULL );
  96  png_set_bgr( png );
  97
  98  switch( info->color_type ) {
  99    case PNG_COLOR_TYPE_GRAY_ALPHA:
 100       mp_msg( MSGT_DECVIDEO,MSGL_INFO,"Sorry gray scaled png with alpha channel not supported at moment.\n" );
 101       break;
 102    case PNG_COLOR_TYPE_GRAY:
 103       out_fmt=IMGFMT_Y800;
 104       break;
 105    case PNG_COLOR_TYPE_PALETTE:
 106       out_fmt=IMGFMT_BGR8;
 107       break;
 108    case PNG_COLOR_TYPE_RGB_ALPHA:
 109       out_fmt=IMGFMT_BGR32;
 110       break;
 111    case PNG_COLOR_TYPE_RGB:
 112       out_fmt=IMGFMT_BGR24;
 113       break;
 114    default:
 115       mp_msg( MSGT_DECVIDEO,MSGL_INFO,"Sorry, unsupported PNG colorspace: %d.\n" ,info->color_type);
 116  }
 117
 118  // (re)init libvo if image parameters changed (width/height/colorspace)
 119  if(last_w!=png_width || last_h!=png_height || last_c!=out_fmt){
 120     last_w=png_width; last_h=png_height; last_c=out_fmt;
 121     if(!out_fmt) return NULL;
 122     if(!mpcodecs_config_vo(sh,png_width,png_height,out_fmt)) return NULL;
 123  }
 124
 125 #if 0
 126  switch( info->color_type )
 127   {
 128    case PNG_COLOR_TYPE_GRAY_ALPHA: printf( "[png] used GrayA -> stripping alpha channel\n" ); break;
 129    case PNG_COLOR_TYPE_GRAY:       printf( "[png] used Gray -> rgb\n" ); break;
 130    case PNG_COLOR_TYPE_PALETTE:    printf( "[png] used palette -> rgb\n" ); break;
 131    case PNG_COLOR_TYPE_RGB_ALPHA:  printf( "[png] used RGBA -> stripping alpha channel\n" ); break;
 132    case PNG_COLOR_TYPE_RGB:        printf( "[png] read rgb datas.\n" ); break;
 133   }
 134 #endif
 135
 136     mpi=mpcodecs_get_image(sh, MP_IMGTYPE_TEMP, MP_IMGFLAG_ACCEPT_STRIDE,
 137         png_width,png_height);
 138     if(!mpi) return NULL;
 139
 140 // Let's DECODE!
 141  row_p=(png_bytep*)malloc( sizeof( png_bytep ) * png_height );
 142 //png_get_rowbytes( png,info )
 143  for ( i=0; i < png_height; i++ ) row_p[i]=mpi->planes[0] + mpi->stride[0]*i;
 144  png_read_image( png,row_p );
 145  free( row_p );
 146
 147  if (out_fmt==IMGFMT_BGR8) {
 148      png_get_PLTE( png,info,&pal,&cols );
 149      mpi->planes[1] = (char*)realloc(mpi->planes[1], 4*cols);
 150      p = mpi->planes[1];
 151      for (i = 0; i < cols; i++) {
 152          *p++ = pal[i].blue;
 153          *p++ = pal[i].green;
 154          *p++ = pal[i].red;
 155          *p++ = 0;
 156      }
 157  }
 158
 159  png_read_end( png,endinfo );
 160  png_destroy_read_struct( &png,&info,&endinfo );
 161
 162     return mpi;
 163 }
 164
 165 #endif