1 /*****************************************************************************
2 * png.c: png decoder module making use of libpng.
3 *****************************************************************************
4 * Copyright (C) 1999-2001 the VideoLAN team
7 * Authors: Gildas Bazin <gbazin@videolan.org>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
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 General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
22 *****************************************************************************/
24 /*****************************************************************************
26 *****************************************************************************/
28 #include <vlc/decoder.h>
32 /*****************************************************************************
33 * decoder_sys_t : png decoder descriptor
34 *****************************************************************************/
40 /*****************************************************************************
42 *****************************************************************************/
43 static int OpenDecoder ( vlc_object_t * );
44 static void CloseDecoder ( vlc_object_t * );
46 static picture_t *DecodeBlock ( decoder_t *, block_t ** );
48 /*****************************************************************************
50 *****************************************************************************/
52 set_category( CAT_INPUT );
53 set_subcategory( SUBCAT_INPUT_VCODEC );
54 set_description( _("PNG video decoder") );
55 set_capability( "decoder", 1000 );
56 set_callbacks( OpenDecoder, CloseDecoder );
57 add_shortcut( "png" );
60 /*****************************************************************************
61 * OpenDecoder: probe the decoder and return score
62 *****************************************************************************/
63 static int OpenDecoder( vlc_object_t *p_this )
65 decoder_t *p_dec = (decoder_t*)p_this;
68 if( p_dec->fmt_in.i_codec != VLC_FOURCC('p','n','g',' ') &&
69 p_dec->fmt_in.i_codec != VLC_FOURCC('M','P','N','G') )
74 /* Allocate the memory needed to store the decoder's structure */
75 if( ( p_dec->p_sys = p_sys =
76 (decoder_sys_t *)malloc(sizeof(decoder_sys_t)) ) == NULL )
78 msg_Err( p_dec, "out of memory" );
82 /* Set output properties */
83 p_dec->fmt_out.i_cat = VIDEO_ES;
84 p_dec->fmt_out.i_codec = VLC_FOURCC('R','V','3','2');
87 p_dec->pf_decode_video = DecodeBlock;
92 static void user_read( png_structp p_png, png_bytep data, png_size_t i_length )
94 block_t *p_block = (block_t *)png_get_io_ptr( p_png );
95 png_size_t i_read = __MIN( p_block->i_buffer, (int)i_length );
96 memcpy( data, p_block->p_buffer, i_length );
97 p_block->p_buffer += i_length;
98 p_block->i_buffer -= i_length;
100 if( i_length != i_read ) png_error( p_png, "not enough data" );
103 static void user_error( png_structp p_png, png_const_charp error_msg )
105 decoder_t *p_dec = (decoder_t *)png_get_error_ptr( p_png );
106 p_dec->p_sys->b_error = VLC_TRUE;
107 msg_Err( p_dec, error_msg );
110 static void user_warning( png_structp p_png, png_const_charp warning_msg )
112 decoder_t *p_dec = (decoder_t *)png_get_error_ptr( p_png );
113 msg_Warn( p_dec, warning_msg );
116 /****************************************************************************
117 * DecodeBlock: the whole thing
118 ****************************************************************************
119 * This function must be fed with a complete compressed frame.
120 ****************************************************************************/
121 static picture_t *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
123 decoder_sys_t *p_sys = p_dec->p_sys;
125 picture_t *p_pic = 0;
127 png_uint_32 i_width, i_height;
128 int i_color_type, i_interlace_type, i_compression_type, i_filter_type;
132 png_infop p_info, p_end_info;
133 png_bytep *p_row_pointers = NULL;
135 if( !pp_block || !*pp_block ) return NULL;
138 p_sys->b_error = VLC_FALSE;
140 p_png = png_create_read_struct( PNG_LIBPNG_VER_STRING, 0, 0, 0 );
143 block_Release( p_block ); *pp_block = NULL;
147 p_info = png_create_info_struct( p_png );
150 png_destroy_read_struct( &p_png, png_infopp_NULL, png_infopp_NULL );
151 block_Release( p_block ); *pp_block = NULL;
155 p_end_info = png_create_info_struct( p_png );
156 if( p_end_info == NULL )
158 png_destroy_read_struct( &p_png, &p_info, png_infopp_NULL );
159 block_Release( p_block ); *pp_block = NULL;
163 /* libpng longjmp's there in case of error */
164 if( setjmp( png_jmpbuf( p_png ) ) )
167 png_set_read_fn( p_png, (void *)p_block, user_read );
168 png_set_error_fn( p_png, (void *)p_dec, user_error, user_warning );
170 png_read_info( p_png, p_info );
171 if( p_sys->b_error ) goto error;
173 png_get_IHDR( p_png, p_info, &i_width, &i_height,
174 &i_bit_depth, &i_color_type, &i_interlace_type,
175 &i_compression_type, &i_filter_type);
176 if( p_sys->b_error ) goto error;
178 /* Set output properties */
179 p_dec->fmt_out.i_codec = VLC_FOURCC('R','V','3','2');
180 p_dec->fmt_out.video.i_width = i_width;
181 p_dec->fmt_out.video.i_height = i_height;
182 p_dec->fmt_out.video.i_aspect = VOUT_ASPECT_FACTOR * i_width / i_height;
184 if( i_color_type == PNG_COLOR_TYPE_PALETTE )
185 png_set_palette_to_rgb( p_png );
187 if( i_color_type == PNG_COLOR_TYPE_GRAY ||
188 i_color_type == PNG_COLOR_TYPE_GRAY_ALPHA )
189 png_set_gray_to_rgb( p_png );
191 /* Strip to 8 bits per channel */
192 if( i_bit_depth == 16 ) png_set_strip_16( p_png );
194 if( png_get_valid( p_png, p_info, PNG_INFO_tRNS ) )
196 png_set_tRNS_to_alpha( p_png );
198 else if( !(i_color_type & PNG_COLOR_MASK_ALPHA) )
200 p_dec->fmt_out.i_codec = VLC_FOURCC('R','V','2','4');
202 if( i_color_type & PNG_COLOR_MASK_COLOR &&
203 p_dec->fmt_out.i_codec != VLC_FOURCC('R','V','2','4') )
206 png_set_bgr( p_png );
209 /* Get a new picture */
210 p_pic = p_dec->pf_vout_buffer_new( p_dec );
211 if( !p_pic ) goto error;
214 p_row_pointers = malloc( sizeof(png_bytep) * i_height );
215 for( i = 0; i < (int)i_height; i++ )
216 p_row_pointers[i] = p_pic->p->p_pixels + p_pic->p->i_pitch * i;
218 png_read_image( p_png, p_row_pointers );
219 if( p_sys->b_error ) goto error;
220 png_read_end( p_png, p_end_info );
221 if( p_sys->b_error ) goto error;
223 png_destroy_read_struct( &p_png, &p_info, &p_end_info );
224 free( p_row_pointers );
226 p_pic->date = p_block->i_pts > 0 ? p_block->i_pts : p_block->i_dts;
228 block_Release( p_block ); *pp_block = NULL;
233 if( p_row_pointers ) free( p_row_pointers );
234 png_destroy_read_struct( &p_png, &p_info, &p_end_info );
235 block_Release( p_block ); *pp_block = NULL;
239 /*****************************************************************************
240 * CloseDecoder: png decoder destruction
241 *****************************************************************************/
242 static void CloseDecoder( vlc_object_t *p_this )
244 decoder_t *p_dec = (decoder_t *)p_this;
245 decoder_sys_t *p_sys = p_dec->p_sys;