1 /*****************************************************************************
2 * png.c: png decoder module making use of libpng.
3 *****************************************************************************
4 * Copyright (C) 1999-2001 VLC authors and VideoLAN
7 * Authors: Gildas Bazin <gbazin@videolan.org>
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.
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.
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 *****************************************************************************/
24 /*****************************************************************************
26 *****************************************************************************/
31 #include <vlc_common.h>
32 #include <vlc_plugin.h>
33 #include <vlc_codec.h>
36 /*****************************************************************************
37 * decoder_sys_t : png decoder descriptor
38 *****************************************************************************/
44 /*****************************************************************************
46 *****************************************************************************/
47 static int OpenDecoder ( vlc_object_t * );
48 static void CloseDecoder ( vlc_object_t * );
50 static picture_t *DecodeBlock ( decoder_t *, block_t ** );
52 /*****************************************************************************
54 *****************************************************************************/
56 set_category( CAT_INPUT )
57 set_subcategory( SUBCAT_INPUT_VCODEC )
58 set_description( N_("PNG video decoder") )
59 set_capability( "decoder", 1000 )
60 set_callbacks( OpenDecoder, CloseDecoder )
64 /*****************************************************************************
65 * OpenDecoder: probe the decoder and return score
66 *****************************************************************************/
67 static int OpenDecoder( vlc_object_t *p_this )
69 decoder_t *p_dec = (decoder_t*)p_this;
71 if( p_dec->fmt_in.i_codec != VLC_CODEC_PNG &&
72 p_dec->fmt_in.i_codec != VLC_FOURCC('M','P','N','G') )
77 /* Allocate the memory needed to store the decoder's structure */
78 if( ( p_dec->p_sys = malloc(sizeof(decoder_sys_t)) ) == NULL )
81 /* Set output properties */
82 p_dec->fmt_out.i_cat = VIDEO_ES;
83 p_dec->fmt_out.i_codec = VLC_CODEC_RGBA;
86 p_dec->pf_decode_video = DecodeBlock;
91 static void user_read( png_structp p_png, png_bytep data, png_size_t i_length )
93 block_t *p_block = (block_t *)png_get_io_ptr( p_png );
94 if( i_length > p_block->i_buffer ) {
95 png_error( p_png, "not enough data" );
99 memcpy( data, p_block->p_buffer, i_length );
100 p_block->p_buffer += i_length;
101 p_block->i_buffer -= i_length;
104 static void user_error( png_structp p_png, png_const_charp error_msg )
106 decoder_t *p_dec = (decoder_t *)png_get_error_ptr( p_png );
107 p_dec->p_sys->b_error = true;
108 msg_Err( p_dec, "%s", error_msg );
111 static void user_warning( png_structp p_png, png_const_charp warning_msg )
113 decoder_t *p_dec = (decoder_t *)png_get_error_ptr( p_png );
114 msg_Warn( p_dec, "%s", warning_msg );
117 /****************************************************************************
118 * DecodeBlock: the whole thing
119 ****************************************************************************
120 * This function must be fed with a complete compressed frame.
121 ****************************************************************************/
122 static picture_t *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
124 decoder_sys_t *p_sys = p_dec->p_sys;
126 picture_t *p_pic = 0;
128 png_uint_32 i_width, i_height;
129 int i_color_type, i_interlace_type, i_compression_type, i_filter_type;
133 png_infop p_info, p_end_info;
134 png_bytep *p_row_pointers = NULL;
136 if( !pp_block || !*pp_block ) return NULL;
139 p_sys->b_error = false;
141 if( p_block->i_flags & BLOCK_FLAG_DISCONTINUITY )
143 block_Release( p_block ); *pp_block = NULL;
147 p_png = png_create_read_struct( PNG_LIBPNG_VER_STRING, 0, 0, 0 );
150 block_Release( p_block ); *pp_block = NULL;
154 p_info = png_create_info_struct( p_png );
157 png_destroy_read_struct( &p_png, NULL, NULL );
158 block_Release( p_block ); *pp_block = NULL;
162 p_end_info = png_create_info_struct( p_png );
163 if( p_end_info == NULL )
165 png_destroy_read_struct( &p_png, &p_info, NULL );
166 block_Release( p_block ); *pp_block = NULL;
170 /* libpng longjmp's there in case of error */
171 if( setjmp( png_jmpbuf( p_png ) ) )
174 png_set_read_fn( p_png, (void *)p_block, user_read );
175 png_set_error_fn( p_png, (void *)p_dec, user_error, user_warning );
177 png_read_info( p_png, p_info );
178 if( p_sys->b_error ) goto error;
180 png_get_IHDR( p_png, p_info, &i_width, &i_height,
181 &i_bit_depth, &i_color_type, &i_interlace_type,
182 &i_compression_type, &i_filter_type);
183 if( p_sys->b_error ) goto error;
185 /* Set output properties */
186 p_dec->fmt_out.i_codec = VLC_CODEC_RGBA;
187 p_dec->fmt_out.video.i_width = i_width;
188 p_dec->fmt_out.video.i_height = i_height;
189 p_dec->fmt_out.video.i_sar_num = 1;
190 p_dec->fmt_out.video.i_sar_den = 1;
191 p_dec->fmt_out.video.i_rmask = 0x000000ff;
192 p_dec->fmt_out.video.i_gmask = 0x0000ff00;
193 p_dec->fmt_out.video.i_bmask = 0x00ff0000;
195 if( i_color_type == PNG_COLOR_TYPE_PALETTE )
196 png_set_palette_to_rgb( p_png );
198 if( i_color_type == PNG_COLOR_TYPE_GRAY ||
199 i_color_type == PNG_COLOR_TYPE_GRAY_ALPHA )
200 png_set_gray_to_rgb( p_png );
202 /* Strip to 8 bits per channel */
203 if( i_bit_depth == 16 ) png_set_strip_16( p_png );
205 if( png_get_valid( p_png, p_info, PNG_INFO_tRNS ) )
207 png_set_tRNS_to_alpha( p_png );
209 else if( !(i_color_type & PNG_COLOR_MASK_ALPHA) )
211 p_dec->fmt_out.i_codec = VLC_CODEC_RGB24;
214 /* Get a new picture */
215 p_pic = decoder_NewPicture( p_dec );
216 if( !p_pic ) goto error;
219 p_row_pointers = malloc( sizeof(png_bytep) * i_height );
220 if( !p_row_pointers )
222 for( i = 0; i < (int)i_height; i++ )
223 p_row_pointers[i] = p_pic->p->p_pixels + p_pic->p->i_pitch * i;
225 png_read_image( p_png, p_row_pointers );
226 if( p_sys->b_error ) goto error;
227 png_read_end( p_png, p_end_info );
228 if( p_sys->b_error ) goto error;
230 png_destroy_read_struct( &p_png, &p_info, &p_end_info );
231 free( p_row_pointers );
233 p_pic->date = p_block->i_pts > VLC_TS_INVALID ? p_block->i_pts : p_block->i_dts;
235 block_Release( p_block ); *pp_block = NULL;
240 free( p_row_pointers );
241 png_destroy_read_struct( &p_png, &p_info, &p_end_info );
242 block_Release( p_block ); *pp_block = NULL;
246 /*****************************************************************************
247 * CloseDecoder: png decoder destruction
248 *****************************************************************************/
249 static void CloseDecoder( vlc_object_t *p_this )
251 decoder_t *p_dec = (decoder_t *)p_this;
252 decoder_sys_t *p_sys = p_dec->p_sys;