modules/codec/png.c

   1 /*****************************************************************************
   2  * png.c: png decoder module making use of libpng.
   3  *****************************************************************************
   4  * Copyright (C) 1999-2001 VLC authors and VideoLAN
   5  * $Id$
   6  *
   7  * Authors: Gildas Bazin <gbazin@videolan.org>
   8  *
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU Lesser General Public License as published by
  11  * the Free Software Foundation; either version 2.1 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17  * GNU Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public License
  20  * along with this program; if not, write to the Free Software Foundation,
  21  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 /*****************************************************************************
  25  * Preamble
  26  *****************************************************************************/
  27 #ifdef HAVE_CONFIG_H
  28 # include "config.h"
  29 #endif
  30
  31 #include <vlc_common.h>
  32 #include <vlc_plugin.h>
  33 #include <vlc_codec.h>
  34 #include <png.h>
  35
  36 /* PNG_SYS_COMMON_MEMBERS:
  37  * members common to encoder and decoder descriptors
  38  */
  39 #define PNG_SYS_COMMON_MEMBERS                              \
  40 /**@{*/                                                     \
  41     bool b_error;                                           \
  42     vlc_object_t *p_obj;                                    \
  43 /**@}*/                                                     \
  44
  45 /*
  46  * png common descriptor
  47  */
  48 struct png_sys_t
  49 {
  50     PNG_SYS_COMMON_MEMBERS
  51 };
  52
  53 typedef struct png_sys_t png_sys_t;
  54
  55 /*****************************************************************************
  56  * decoder_sys_t : png decoder descriptor
  57  *****************************************************************************/
  58 typedef struct
  59 {
  60     PNG_SYS_COMMON_MEMBERS
  61 } decoder_sys_t;
  62
  63 /*****************************************************************************
  64  * Local prototypes
  65  *****************************************************************************/
  66 static int  OpenDecoder   ( vlc_object_t * );
  67 static void CloseDecoder  ( vlc_object_t * );
  68
  69 static int DecodeBlock  ( decoder_t *, block_t * );
  70
  71 /*
  72  * png encoder descriptor
  73  */
  74 typedef struct
  75 {
  76     PNG_SYS_COMMON_MEMBERS
  77     int i_blocksize;
  78 } encoder_sys_t;
  79
  80 static int  OpenEncoder(vlc_object_t *);
  81 static void CloseEncoder(vlc_object_t *);
  82
  83 static block_t *EncodeBlock(encoder_t *, picture_t *);
  84
  85 /*****************************************************************************
  86  * Module descriptor
  87  *****************************************************************************/
  88 vlc_module_begin ()
  89     set_category( CAT_INPUT )
  90     set_subcategory( SUBCAT_INPUT_VCODEC )
  91     set_description( N_("PNG video decoder") )
  92     set_capability( "video decoder", 1000 )
  93     set_callbacks( OpenDecoder, CloseDecoder )
  94     add_shortcut( "png" )
  95
  96     /* encoder submodule */
  97     add_submodule()
  98     add_shortcut("png")
  99     set_section(N_("Encoding"), NULL)
 100     set_description(N_("PNG video encoder"))
 101     set_capability("encoder", 1000)
 102     set_callbacks(OpenEncoder, CloseEncoder)
 103 vlc_module_end ()
 104
 105 /*****************************************************************************
 106  * OpenDecoder: probe the decoder and return score
 107  *****************************************************************************/
 108 static int OpenDecoder( vlc_object_t *p_this )
 109 {
 110     decoder_t *p_dec = (decoder_t*)p_this;
 111
 112     if( p_dec->fmt_in.i_codec != VLC_CODEC_PNG &&
 113         p_dec->fmt_in.i_codec != VLC_FOURCC('M','P','N','G') )
 114     {
 115         return VLC_EGENERIC;
 116     }
 117
 118     /* Allocate the memory needed to store the decoder's structure */
 119     decoder_sys_t *p_sys = malloc( sizeof(decoder_sys_t) );
 120     if( p_sys == NULL )
 121         return VLC_ENOMEM;
 122     p_dec->p_sys = p_sys;
 123
 124     p_sys->p_obj = p_this;
 125
 126     /* Set output properties */
 127     p_dec->fmt_out.i_codec = VLC_CODEC_RGBA;
 128     p_dec->fmt_out.video.transfer = TRANSFER_FUNC_SRGB;
 129     p_dec->fmt_out.video.b_color_range_full = true;
 130
 131     /* Set callbacks */
 132     p_dec->pf_decode = DecodeBlock;
 133
 134     return VLC_SUCCESS;
 135 }
 136
 137 static void user_read( png_structp p_png, png_bytep data, png_size_t i_length )
 138 {
 139     block_t *p_block = (block_t *)png_get_io_ptr( p_png );
 140     if( i_length > p_block->i_buffer ) {
 141         png_error( p_png, "not enough data" );
 142         return;
 143     }
 144
 145     memcpy( data, p_block->p_buffer, i_length );
 146     p_block->p_buffer += i_length;
 147     p_block->i_buffer -= i_length;
 148 }
 149
 150 static void user_flush( png_structp p_png )
 151 {
 152     /* noop */
 153     (void) p_png;
 154 }
 155
 156 static void user_write( png_structp p_png, png_bytep data, png_size_t i_length )
 157 {
 158     block_t *p_block = (block_t *)png_get_io_ptr( p_png );
 159     if( i_length > p_block->i_buffer ) {
 160         char err_str[64];
 161         snprintf( err_str, sizeof(err_str),
 162                   "block size %zu too small for %zu encoded bytes",
 163                   p_block->i_buffer, i_length );
 164         png_error( p_png, err_str );
 165         return;
 166     }
 167
 168     memcpy( p_block->p_buffer, data, i_length );
 169     p_block->p_buffer += i_length;
 170     p_block->i_buffer -= i_length;
 171 }
 172
 173 static void user_error( png_structp p_png, png_const_charp error_msg )
 174 {
 175     png_sys_t *p_sys = (png_sys_t *)png_get_error_ptr( p_png );
 176     p_sys->b_error = true;
 177     msg_Err( p_sys->p_obj, "%s", error_msg );
 178 }
 179
 180 static void user_warning( png_structp p_png, png_const_charp warning_msg )
 181 {
 182     png_sys_t *p_sys = (png_sys_t *)png_get_error_ptr( p_png );
 183     msg_Warn( p_sys->p_obj, "%s", warning_msg );
 184 }
 185
 186 /****************************************************************************
 187  * DecodeBlock: the whole thing
 188  ****************************************************************************
 189  * This function must be fed with a complete compressed frame.
 190  ****************************************************************************/
 191 static int DecodeBlock( decoder_t *p_dec, block_t *p_block )
 192 {
 193     decoder_sys_t *p_sys = p_dec->p_sys;
 194     picture_t *p_pic = 0;
 195
 196     png_uint_32 i_width, i_height;
 197     int i_color_type, i_interlace_type, i_compression_type, i_filter_type;
 198     int i_bit_depth, i;
 199
 200     png_structp p_png;
 201     png_infop p_info, p_end_info;
 202     png_bytep *volatile p_row_pointers = NULL;
 203
 204     if( !p_block ) /* No Drain */
 205         return VLCDEC_SUCCESS;
 206
 207     p_sys->b_error = false;
 208
 209     if( p_block->i_flags & BLOCK_FLAG_CORRUPTED )
 210     {
 211         block_Release( p_block );
 212         return VLCDEC_SUCCESS;
 213     }
 214
 215     p_png = png_create_read_struct( PNG_LIBPNG_VER_STRING, 0, 0, 0 );
 216     if( p_png == NULL )
 217     {
 218         block_Release( p_block );
 219         return VLCDEC_SUCCESS;
 220     }
 221
 222     p_info = png_create_info_struct( p_png );
 223     if( p_info == NULL )
 224     {
 225         png_destroy_read_struct( &p_png, NULL, NULL );
 226         block_Release( p_block );
 227         return VLCDEC_SUCCESS;
 228     }
 229
 230     p_end_info = png_create_info_struct( p_png );
 231     if( p_end_info == NULL )
 232     {
 233         png_destroy_read_struct( &p_png, &p_info, NULL );
 234         block_Release( p_block );
 235         return VLCDEC_SUCCESS;
 236     }
 237
 238     /* libpng longjmp's there in case of error */
 239     if( setjmp( png_jmpbuf( p_png ) ) )
 240         goto error;
 241
 242     png_set_read_fn( p_png, (void *)p_block, user_read );
 243     png_set_error_fn( p_png, (void *)p_dec, user_error, user_warning );
 244
 245     png_read_info( p_png, p_info );
 246     if( p_sys->b_error ) goto error;
 247
 248     png_get_IHDR( p_png, p_info, &i_width, &i_height,
 249                   &i_bit_depth, &i_color_type, &i_interlace_type,
 250                   &i_compression_type, &i_filter_type);
 251     if( p_sys->b_error ) goto error;
 252
 253     /* Set output properties */
 254     p_dec->fmt_out.i_codec = VLC_CODEC_RGBA;
 255     p_dec->fmt_out.video.i_visible_width = p_dec->fmt_out.video.i_width = i_width;
 256     p_dec->fmt_out.video.i_visible_height = p_dec->fmt_out.video.i_height = i_height;
 257     p_dec->fmt_out.video.i_sar_num = 1;
 258     p_dec->fmt_out.video.i_sar_den = 1;
 259
 260     if( i_color_type == PNG_COLOR_TYPE_PALETTE )
 261         png_set_palette_to_rgb( p_png );
 262
 263     if( i_color_type == PNG_COLOR_TYPE_GRAY ||
 264         i_color_type == PNG_COLOR_TYPE_GRAY_ALPHA )
 265           png_set_gray_to_rgb( p_png );
 266     if( i_color_type & PNG_COLOR_MASK_ALPHA )
 267         png_set_alpha_mode( p_png, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB );
 268
 269     /* Strip to 8 bits per channel */
 270     if( i_bit_depth == 16 )
 271     {
 272 #if PNG_LIBPNG_VER >= 10504
 273         png_set_scale_16( p_png );
 274 #else
 275         png_set_strip_16( p_png );
 276 #endif
 277     }
 278
 279     if( png_get_valid( p_png, p_info, PNG_INFO_tRNS ) )
 280     {
 281         png_set_tRNS_to_alpha( p_png );
 282     }
 283     else if( !(i_color_type & PNG_COLOR_MASK_ALPHA) )
 284     {
 285         p_dec->fmt_out.i_codec = VLC_CODEC_RGB24;
 286     }
 287
 288     /* Get a new picture */
 289     if( decoder_UpdateVideoFormat( p_dec ) )
 290         goto error;
 291     p_pic = decoder_NewPicture( p_dec );
 292     if( !p_pic ) goto error;
 293
 294     /* Decode picture */
 295     p_row_pointers = vlc_alloc( i_height, sizeof(png_bytep) );
 296     if( !p_row_pointers )
 297         goto error;
 298     for( i = 0; i < (int)i_height; i++ )
 299         p_row_pointers[i] = p_pic->p->p_pixels + p_pic->p->i_pitch * i;
 300
 301     png_read_image( p_png, p_row_pointers );
 302     if( p_sys->b_error ) goto error;
 303     png_read_end( p_png, p_end_info );
 304     if( p_sys->b_error ) goto error;
 305
 306     png_destroy_read_struct( &p_png, &p_info, &p_end_info );
 307     free( p_row_pointers );
 308
 309     p_pic->date = p_block->i_pts != VLC_TICK_INVALID ? p_block->i_pts : p_block->i_dts;
 310
 311     block_Release( p_block );
 312     decoder_QueueVideo( p_dec, p_pic );
 313     return VLCDEC_SUCCESS;
 314
 315  error:
 316
 317     free( p_row_pointers );
 318     png_destroy_read_struct( &p_png, &p_info, &p_end_info );
 319     block_Release( p_block );
 320     return VLCDEC_SUCCESS;
 321 }
 322
 323 /*****************************************************************************
 324  * CloseDecoder: png decoder destruction
 325  *****************************************************************************/
 326 static void CloseDecoder( vlc_object_t *p_this )
 327 {
 328     decoder_t *p_dec = (decoder_t *)p_this;
 329     decoder_sys_t *p_sys = p_dec->p_sys;
 330
 331     free( p_sys );
 332 }
 333
 334 static int OpenEncoder(vlc_object_t *p_this)
 335 {
 336     encoder_t *p_enc = (encoder_t *) p_this;
 337
 338     if( p_enc->fmt_out.i_codec != VLC_CODEC_PNG )
 339         return VLC_EGENERIC;
 340
 341     /* Allocate the memory needed to store the encoder's structure */
 342     encoder_sys_t *p_sys = malloc( sizeof(encoder_sys_t) );
 343     if( p_sys == NULL )
 344         return VLC_ENOMEM;
 345     p_enc->p_sys = p_sys;
 346
 347     p_sys->p_obj = p_this;
 348
 349     p_sys->i_blocksize = 3 * p_enc->fmt_in.video.i_visible_width *
 350         p_enc->fmt_in.video.i_visible_height;
 351
 352     p_enc->fmt_in.i_codec = VLC_CODEC_RGB24;
 353     p_enc->fmt_in.video.i_bmask = 0;
 354     video_format_FixRgb( &p_enc->fmt_in.video );
 355
 356     p_enc->pf_encode_video = EncodeBlock;
 357
 358     return VLC_SUCCESS;
 359 }
 360
 361 /*
 362  * EncodeBlock
 363  */
 364 static block_t *EncodeBlock(encoder_t *p_enc, picture_t *p_pic)
 365 {
 366     encoder_sys_t *p_sys = p_enc->p_sys;
 367
 368     if( unlikely( !p_pic ) )
 369     {
 370         return NULL;
 371     }
 372
 373     block_t *p_block = block_Alloc( p_sys->i_blocksize );
 374     if( p_block == NULL )
 375     {
 376         return NULL;
 377     }
 378
 379     png_structp p_png = png_create_write_struct( PNG_LIBPNG_VER_STRING, 0, 0, 0 );
 380     if( p_png == NULL )
 381     {
 382         block_Release( p_block );
 383         return NULL;
 384     }
 385
 386     /* Disable filtering to speed-up encoding */
 387     png_set_filter( p_png, 0, PNG_NO_FILTERS );
 388     /* 1 == best speed */
 389     png_set_compression_level( p_png, 1 );
 390
 391     /* save buffer start */
 392     uint8_t *p_start = p_block->p_buffer;
 393     size_t i_start = p_block->i_buffer;
 394
 395     p_sys->b_error = false;
 396     png_infop p_info = NULL;
 397
 398     /* libpng longjmp's there in case of error */
 399     if( setjmp( png_jmpbuf( p_png ) ) )
 400         goto error;
 401
 402     png_set_write_fn( p_png, p_block, user_write, user_flush );
 403     png_set_error_fn( p_png, p_enc, user_error, user_warning );
 404
 405     p_info = png_create_info_struct( p_png );
 406     if( p_info == NULL )
 407         goto error;
 408
 409     png_set_IHDR( p_png, p_info,
 410             p_enc->fmt_in.video.i_visible_width,
 411             p_enc->fmt_in.video.i_visible_height,
 412             8, PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE,
 413             PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT );
 414     if( p_sys->b_error ) goto error;
 415
 416     png_write_info( p_png, p_info );
 417     if( p_sys->b_error ) goto error;
 418
 419     /* Encode picture */
 420
 421     for( int i = 0; i < p_pic->p->i_visible_lines; i++ )
 422     {
 423         png_write_row( p_png, p_pic->p->p_pixels + (i * p_pic->p->i_pitch) );
 424         if( p_sys->b_error ) goto error;
 425     }
 426
 427     png_write_end( p_png, p_info );
 428     if( p_sys->b_error ) goto error;
 429
 430     png_destroy_write_struct( &p_png, &p_info );
 431
 432     /* restore original buffer position */
 433     p_block->p_buffer = p_start;
 434     p_block->i_buffer = i_start - p_block->i_buffer;
 435
 436     p_block->i_dts = p_block->i_pts = p_pic->date;
 437
 438     return p_block;
 439
 440  error:
 441
 442     png_destroy_write_struct( &p_png, p_info ? &p_info : NULL );
 443
 444     block_Release(p_block);
 445     return NULL;
 446 }
 447
 448 /*****************************************************************************
 449  * CloseEncoder: png encoder destruction
 450  *****************************************************************************/
 451 static void CloseEncoder( vlc_object_t *p_this )
 452 {
 453     encoder_t *p_enc = (encoder_t *)p_this;
 454     encoder_sys_t *p_sys = p_enc->p_sys;
 455
 456     free( p_sys );
 457 }