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) );
44 char header[MAX_YUV4_HEADER+10];
45 char *tokend, *header_end;
46 int colorspace = X264_CSP_NONE;
47 int alt_colorspace = X264_CSP_NONE;
54 if( !strcmp( psz_filename, "-" ) )
57 h->fh = fopen(psz_filename, "rb");
61 h->frame_header_len = strlen( Y4M_FRAME_MAGIC )+1;
64 for( i = 0; i < MAX_YUV4_HEADER; i++ )
66 header[i] = fgetc( h->fh );
67 if( header[i] == '\n' )
69 /* Add a space after last option. Makes parsing "444" vs
76 if( i == MAX_YUV4_HEADER || strncmp( header, Y4M_MAGIC, strlen( Y4M_MAGIC ) ) )
80 header_end = &header[i+1]; /* Include space */
81 h->seq_header_len = i+1;
82 for( char *tokstart = &header[strlen( Y4M_MAGIC )+1]; tokstart < header_end; tokstart++ )
84 if( *tokstart == 0x20 )
88 case 'W': /* Width. Required. */
89 h->width = info->width = strtol( tokstart, &tokend, 10 );
92 case 'H': /* Height. Required. */
93 h->height = info->height = strtol( tokstart, &tokend, 10 );
96 case 'C': /* Color space */
97 if( !strncmp( "420", tokstart, 3 ) )
98 colorspace = X264_CSP_I420;
100 colorspace = X264_CSP_MAX; ///< anything other than 420 since we don't handle it
101 tokstart = strchr( tokstart, 0x20 );
103 case 'I': /* Interlace type */
104 switch( *tokstart++ )
112 info->interlaced = 1;
115 case 'F': /* Frame rate - 0:0 if unknown */
116 if( sscanf( tokstart, "%d:%d", &n, &d ) == 2 && n && d )
118 x264_reduce_fraction( &n, &d );
122 tokstart = strchr( tokstart, 0x20 );
124 case 'A': /* Pixel aspect - 0:0 if unknown */
125 /* Don't override the aspect ratio if sar has been explicitly set on the commandline. */
126 if( sscanf( tokstart, "%d:%d", &n, &d ) == 2 && n && d )
128 x264_reduce_fraction( &n, &d );
130 info->sar_height = d;
132 tokstart = strchr( tokstart, 0x20 );
134 case 'X': /* Vendor extensions */
135 if( !strncmp( "YSCSS=", tokstart, 6 ) )
137 /* Older nonstandard pixel format representation */
139 if( !strncmp( "420",tokstart, 3 ) )
140 alt_colorspace = X264_CSP_I420;
142 alt_colorspace = X264_CSP_MAX;
144 tokstart = strchr( tokstart, 0x20 );
149 if( colorspace == X264_CSP_NONE )
150 colorspace = alt_colorspace;
152 // default to 4:2:0 if nothing is specified
153 if( colorspace == X264_CSP_NONE )
154 colorspace = X264_CSP_I420;
156 if( colorspace != X264_CSP_I420 )
158 fprintf( stderr, "y4m [error]: colorspace unhandled\n" );
166 /* Most common case: frame_header = "FRAME" */
167 static int get_frame_total( hnd_t handle )
169 y4m_hnd_t *h = handle;
170 int i_frame_total = 0;
172 if( x264_is_regular_file( h->fh ) )
174 uint64_t init_pos = ftell( h->fh );
175 fseek( h->fh, 0, SEEK_END );
176 uint64_t i_size = ftell( h->fh );
177 fseek( h->fh, init_pos, SEEK_SET );
178 i_frame_total = (int)((i_size - h->seq_header_len) /
179 (3*(h->width*h->height)/2+h->frame_header_len));
182 return i_frame_total;
185 static int read_frame_internal( x264_picture_t *p_pic, y4m_hnd_t *h )
187 int slen = strlen( Y4M_FRAME_MAGIC );
191 /* Read frame header - without terminating '\n' */
192 if( fread( header, 1, slen, h->fh ) != slen )
196 if( strncmp( header, Y4M_FRAME_MAGIC, slen ) )
198 fprintf( stderr, "y4m [error]: bad header magic (%"PRIx32" <=> %s)\n",
199 M32(header), header );
203 /* Skip most of it */
204 while( i < MAX_FRAME_HEADER && fgetc( h->fh ) != '\n' )
206 if( i == MAX_FRAME_HEADER )
208 fprintf( stderr, "y4m [error]: bad frame header!\n" );
211 h->frame_header_len = i+slen+1;
213 if( fread( p_pic->img.plane[0], h->width * h->height, 1, h->fh ) <= 0
214 || fread( p_pic->img.plane[1], h->width * h->height / 4, 1, h->fh ) <= 0
215 || fread( p_pic->img.plane[2], h->width * h->height / 4, 1, h->fh ) <= 0 )
221 static int read_frame( x264_picture_t *p_pic, hnd_t handle, int i_frame )
223 y4m_hnd_t *h = handle;
225 if( i_frame > h->next_frame )
227 if( x264_is_regular_file( h->fh ) )
228 fseek( h->fh, (uint64_t)i_frame*(3*(h->width*h->height)/2+h->frame_header_len)
229 + h->seq_header_len, SEEK_SET );
231 while( i_frame > h->next_frame )
233 if( read_frame_internal( p_pic, h ) )
239 if( read_frame_internal( p_pic, h ) )
242 h->next_frame = i_frame+1;
246 static int close_file( hnd_t handle )
248 y4m_hnd_t *h = handle;
256 const cli_input_t y4m_input = { open_file, get_frame_total, x264_picture_alloc, read_frame, NULL, x264_picture_clean, close_file };