1 /*****************************************************************************
2 * y4m.c: x264 y4m input module
3 *****************************************************************************
4 * Copyright (C) 2003-2009 x264 project
6 * Authors: Laurent Aimar <fenrir@via.ecp.fr>
7 * Loren Merritt <lorenm@u.washington.edu>
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 02111, USA.
22 *****************************************************************************/
31 int seq_header_len, frame_header_len;
35 #define Y4M_MAGIC "YUV4MPEG2"
36 #define MAX_YUV4_HEADER 80
37 #define Y4M_FRAME_MAGIC "FRAME"
38 #define MAX_FRAME_HEADER 80
40 static int open_file( char *psz_filename, hnd_t *p_handle, video_info_t *info, cli_input_opt_t *opt )
42 y4m_hnd_t *h = malloc( sizeof(y4m_hnd_t) );
45 char header[MAX_YUV4_HEADER+10];
46 char *tokend, *header_end;
47 int colorspace = X264_CSP_NONE;
48 int alt_colorspace = X264_CSP_NONE;
55 if( !strcmp( psz_filename, "-" ) )
58 h->fh = fopen(psz_filename, "rb");
62 h->frame_header_len = strlen( Y4M_FRAME_MAGIC )+1;
65 for( i = 0; i < MAX_YUV4_HEADER; i++ )
67 header[i] = fgetc( h->fh );
68 if( header[i] == '\n' )
70 /* Add a space after last option. Makes parsing "444" vs
77 if( i == MAX_YUV4_HEADER || strncmp( header, Y4M_MAGIC, strlen( Y4M_MAGIC ) ) )
81 header_end = &header[i+1]; /* Include space */
82 h->seq_header_len = i+1;
83 for( char *tokstart = &header[strlen( Y4M_MAGIC )+1]; tokstart < header_end; tokstart++ )
85 if( *tokstart == 0x20 )
89 case 'W': /* Width. Required. */
90 h->width = info->width = strtol( tokstart, &tokend, 10 );
93 case 'H': /* Height. Required. */
94 h->height = info->height = strtol( tokstart, &tokend, 10 );
97 case 'C': /* Color space */
98 if( !strncmp( "420", tokstart, 3 ) )
99 colorspace = X264_CSP_I420;
101 colorspace = X264_CSP_MAX; ///< anything other than 420 since we don't handle it
102 tokstart = strchr( tokstart, 0x20 );
104 case 'I': /* Interlace type */
105 switch( *tokstart++ )
108 info->interlaced = 1;
112 info->interlaced = 1;
116 info->interlaced = 1;
124 case 'F': /* Frame rate - 0:0 if unknown */
125 if( sscanf( tokstart, "%d:%d", &n, &d ) == 2 && n && d )
127 x264_reduce_fraction( &n, &d );
131 tokstart = strchr( tokstart, 0x20 );
133 case 'A': /* Pixel aspect - 0:0 if unknown */
134 /* Don't override the aspect ratio if sar has been explicitly set on the commandline. */
135 if( sscanf( tokstart, "%d:%d", &n, &d ) == 2 && n && d )
137 x264_reduce_fraction( &n, &d );
139 info->sar_height = d;
141 tokstart = strchr( tokstart, 0x20 );
143 case 'X': /* Vendor extensions */
144 if( !strncmp( "YSCSS=", tokstart, 6 ) )
146 /* Older nonstandard pixel format representation */
148 if( !strncmp( "420",tokstart, 3 ) )
149 alt_colorspace = X264_CSP_I420;
151 alt_colorspace = X264_CSP_MAX;
153 tokstart = strchr( tokstart, 0x20 );
158 if( colorspace == X264_CSP_NONE )
159 colorspace = alt_colorspace;
161 // default to 4:2:0 if nothing is specified
162 if( colorspace == X264_CSP_NONE )
163 colorspace = X264_CSP_I420;
165 if( colorspace != X264_CSP_I420 )
167 fprintf( stderr, "y4m [error]: colorspace unhandled\n" );
175 /* Most common case: frame_header = "FRAME" */
176 static int get_frame_total( hnd_t handle )
178 y4m_hnd_t *h = handle;
179 int i_frame_total = 0;
181 if( x264_is_regular_file( h->fh ) )
183 uint64_t init_pos = ftell( h->fh );
184 fseek( h->fh, 0, SEEK_END );
185 uint64_t i_size = ftell( h->fh );
186 fseek( h->fh, init_pos, SEEK_SET );
187 i_frame_total = (int)((i_size - h->seq_header_len) /
188 (3*(h->width*h->height)/2+h->frame_header_len));
191 return i_frame_total;
194 static int read_frame_internal( x264_picture_t *p_pic, y4m_hnd_t *h )
196 int slen = strlen( Y4M_FRAME_MAGIC );
200 /* Read frame header - without terminating '\n' */
201 if( fread( header, 1, slen, h->fh ) != slen )
205 if( strncmp( header, Y4M_FRAME_MAGIC, slen ) )
207 fprintf( stderr, "y4m [error]: bad header magic (%"PRIx32" <=> %s)\n",
208 M32(header), header );
212 /* Skip most of it */
213 while( i < MAX_FRAME_HEADER && fgetc( h->fh ) != '\n' )
215 if( i == MAX_FRAME_HEADER )
217 fprintf( stderr, "y4m [error]: bad frame header!\n" );
220 h->frame_header_len = i+slen+1;
222 if( fread( p_pic->img.plane[0], h->width * h->height, 1, h->fh ) <= 0
223 || fread( p_pic->img.plane[1], h->width * h->height / 4, 1, h->fh ) <= 0
224 || fread( p_pic->img.plane[2], h->width * h->height / 4, 1, h->fh ) <= 0 )
230 static int read_frame( x264_picture_t *p_pic, hnd_t handle, int i_frame )
232 y4m_hnd_t *h = handle;
234 if( i_frame > h->next_frame )
236 if( x264_is_regular_file( h->fh ) )
237 fseek( h->fh, (uint64_t)i_frame*(3*(h->width*h->height)/2+h->frame_header_len)
238 + h->seq_header_len, SEEK_SET );
240 while( i_frame > h->next_frame )
242 if( read_frame_internal( p_pic, h ) )
248 if( read_frame_internal( p_pic, h ) )
251 h->next_frame = i_frame+1;
255 static int close_file( hnd_t handle )
257 y4m_hnd_t *h = handle;
265 const cli_input_t y4m_input = { open_file, get_frame_total, x264_picture_alloc, read_frame, NULL, x264_picture_clean, close_file };