edid-decode.h

   1 // SPDX-License-Identifier: MIT
   2 /*
   3  * Copyright 2006-2012 Red Hat, Inc.
   4  * Copyright 2018-2020 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
   5  *
   6  * Author: Adam Jackson <ajax@nwnk.net>
   7  * Maintainer: Hans Verkuil <hverkuil-cisco@xs4all.nl>
   8  */
   9
  10 #ifndef __EDID_DECODE_H_
  11 #define __EDID_DECODE_H_
  12
  13 #include <string>
  14 #include <vector>
  15 #include <set>
  16 #include <string.h>
  17
  18 #define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x)))
  19 #define min(a, b) ((a) < (b) ? (a) : (b))
  20 #define max(a, b) ((a) > (b) ? (a) : (b))
  21
  22 #define EDID_PAGE_SIZE 128U
  23 #define EDID_MAX_BLOCKS 256U
  24
  25 #define RB_ALT          (1U << 7)
  26
  27 #define RB_NONE         (0U)
  28 #define RB_CVT_V1       (1U)
  29 #define RB_CVT_V2       (2U)
  30 #define RB_CVT_V3       (3U)
  31 #define RB_GTF          (4U)
  32
  33 // Video Timings
  34 // If interlaced is true, then the vertical blanking
  35 // for each field is (vfp + vsync + vbp + 0.5), except for
  36 // the VIC 39 timings that doesn't have the 0.5 constant.
  37 //
  38 // The sequence of the various video parameters is as follows:
  39 //
  40 // border - front porch - sync - back porch - border - active video
  41 //
  42 // Note: this is slightly different from EDID 1.4 which calls
  43 // 'active video' as 'addressable video' and the EDID 1.4 term
  44 // 'active video' includes the borders.
  45 //
  46 // But since borders are rarely used, the term 'active video' will
  47 // typically be the same as 'addressable video', and that's how I
  48 // use it.
  49 struct timings {
  50         // Active horizontal and vertical frame height, excluding any
  51         // borders, if present.
  52         // Note: for interlaced formats the active field height is vact / 2
  53         unsigned hact, vact;
  54         unsigned hratio, vratio;
  55         unsigned pixclk_khz;
  56         // 0: no reduced blanking
  57         // 1: CVT reduced blanking version 1
  58         // 2: CVT reduced blanking version 2
  59         // 2 | RB_ALT: CVT reduced blanking version 2 video-optimized (1000/1001 fps)
  60         // 3: CVT reduced blanking version 3
  61         // 3 | RB_ALT: v3 with a horizontal blank of 160
  62         // 4: GTF Secondary Curve
  63         unsigned rb;
  64         bool interlaced;
  65         // The horizontal frontporch may be negative in GTF calculations,
  66         // so use int instead of unsigned for hfp. Example: 292x176@76.
  67         int hfp;
  68         unsigned hsync;
  69         // The backporch may be negative in buggy detailed timings.
  70         // So use int instead of unsigned for hbp and vbp.
  71         int hbp;
  72         bool pos_pol_hsync;
  73         // For interlaced formats the vertical front porch of the Even Field
  74         // is actually a half-line longer.
  75         unsigned vfp, vsync;
  76         // For interlaced formats the vertical back porch of the Odd Field
  77         // is actually a half-line longer.
  78         int vbp;
  79         bool pos_pol_vsync;
  80         unsigned hborder, vborder;
  81         bool even_vtotal; // special for VIC 39
  82         bool no_pol_vsync; // digital composite signals have no vsync polarity
  83         unsigned hsize_mm, vsize_mm;
  84         bool ycbcr420; // YCbCr 4:2:0 encoding
  85 };
  86
  87 struct timings_ext {
  88         timings_ext()
  89         {
  90                 memset(&t, 0, sizeof(t));
  91         }
  92         timings_ext(unsigned svr, const std::string &_type)
  93         {
  94                 memset(&t, 0, sizeof(t));
  95                 t.hact = svr;
  96                 type = _type;
  97         }
  98         timings_ext(const timings &_t, const std::string &_type, const std::string &_flags)
  99         {
 100                 t = _t;
 101                 type = _type;
 102                 flags = _flags;
 103         }
 104
 105         bool is_valid() const { return t.hact; }
 106         bool has_svr() const { return t.hact && !t.vact; }
 107         unsigned svr() const { return t.hact; }
 108         timings t;
 109         std::string type;
 110         std::string flags;
 111 };
 112
 113 enum gtf_ip_parm {
 114         gtf_ip_vert_freq = 1,
 115         gtf_ip_hor_freq,
 116         gtf_ip_clk_freq,
 117 };
 118
 119 typedef std::vector<timings_ext> vec_timings_ext;
 120
 121 struct cta_rid {
 122         unsigned hact, vact;
 123         unsigned hratio, vratio;
 124 };
 125
 126 struct cta_vfd {
 127         unsigned char rid;
 128         unsigned char fr_factor;
 129         unsigned int bfr50:1;
 130         unsigned int fr24:1;
 131         unsigned int bfr60:1;
 132         unsigned int fr144:1;
 133         unsigned int fr48:1;
 134 };
 135
 136 struct edid_state {
 137         edid_state()
 138         {
 139                 // Global state
 140                 edid_size = num_blocks = block_nr = 0;
 141                 max_hor_freq_hz = max_vert_freq_hz = max_pixclk_khz = 0;
 142                 min_hor_freq_hz = 0xffffff;
 143                 min_vert_freq_hz = 0xffffffff;
 144                 dtd_max_vsize_mm = dtd_max_hsize_mm = 0;
 145                 warnings = failures = 0;
 146                 has_cta = has_dispid = false;
 147                 hide_serial_numbers = false;
 148                 replace_unique_ids = false;
 149                 image_width = image_height = diagonal = 0;
 150                 serial_string_cnt = 0;
 151                 serial_strings.clear();
 152
 153                 // Base block state
 154                 base.edid_minor = 0;
 155                 base.has_name_descriptor = base.has_display_range_descriptor =
 156                         base.supports_continuous_freq = base.supports_gtf =
 157                         base.supports_cvt = base.seen_non_detailed_descriptor =
 158                         base.has_640x480p60_est_timing = base.has_spwg =
 159                         base.preferred_is_also_native = false;
 160                 base.serial_number = 0;
 161                 base.week = base.year = 0;
 162                 base.supports_sec_gtf = false;
 163                 base.sec_gtf_start_freq = 0;
 164                 base.C = base.M = base.K = base.J = 0;
 165                 base.max_pos_neg_hor_freq_khz = 0;
 166                 base.uses_srgb = false;
 167                 base.detailed_block_cnt = base.dtd_cnt = 0;
 168
 169                 base.min_display_hor_freq_hz = base.max_display_hor_freq_hz =
 170                         base.min_display_vert_freq_hz = base.max_display_vert_freq_hz =
 171                         base.max_display_pixclk_khz = base.max_display_width_mm =
 172                         base.max_display_height_mm = 0;
 173
 174                 // CTA-861 block state
 175                 cta.has_vic_1 = cta.first_svd_might_be_preferred = cta.has_sldb =
 176                         cta.has_hdmi = cta.has_vcdb = cta.has_vfpdb = cta.has_cdb =
 177                         cta.has_nvrdb = false;
 178                 cta.previous_cta_tag = 0xfff;
 179                 cta.have_hf_vsdb = cta.have_hf_scdb = false;
 180                 cta.hdmi_max_rate = 0;
 181                 cta.hf_eeodb_blocks = 0;
 182                 cta.image_width = cta.image_height = 0;
 183                 cta.block_number = 0;
 184                 cta.has_svrs = false;
 185                 cta.first_svd = true;
 186                 cta.supported_hdmi_vic_codes = cta.supported_hdmi_vic_vsb_codes = 0;
 187                 memset(cta.vics, 0, sizeof(cta.vics));
 188                 memset(cta.preparsed_has_vic, 0, sizeof(cta.preparsed_has_vic));
 189                 memset(&cta.preparsed_first_vfd, 0, sizeof(cta.preparsed_first_vfd));
 190                 cta.preparsed_phys_addr = 0xffff;
 191                 cta.preparsed_speaker_count = 0;
 192                 cta.preparsed_sld = false;
 193                 cta.preparsed_sld_has_coord = false;
 194                 cta.preparsed_total_dtds = 0;
 195                 cta.preparsed_total_vtdbs = 0;
 196                 cta.preparsed_has_t8vtdb = false;
 197                 cta.preparsed_t8vtdb_dmt = 0;
 198                 cta.preparsed_max_vic_pixclk_khz = 0;
 199                 cta.warn_about_hdmi_2x_dtd = false;
 200
 201                 // DisplayID block state
 202                 dispid.version = 0;
 203                 dispid.native_width = dispid.native_height = 0;
 204                 dispid.preparsed_color_ids = dispid.preparsed_xfer_ids = 0;
 205                 dispid.preparsed_displayid_blocks = 0;
 206                 dispid.is_base_block = true;
 207                 dispid.is_display = dispid.has_product_identification =
 208                         dispid.has_display_parameters = dispid.has_type_1_7 =
 209                         dispid.has_display_interface_features = false;
 210                 dispid.block_number = 0;
 211                 dispid.image_width = dispid.image_height = 0;
 212
 213                 // Block Map block state
 214                 block_map.saw_block_1 = false;
 215                 block_map.saw_block_128 = false;
 216         }
 217
 218         // Global state
 219         unsigned edid_size;
 220         unsigned num_blocks;
 221         unsigned block_nr;
 222         std::string block;
 223         std::string data_block;
 224         unsigned unused_bytes;
 225         bool has_cta;
 226         bool has_dispid;
 227         bool hide_serial_numbers;
 228         bool replace_unique_ids;
 229         std::vector<std::string> serial_strings;
 230         unsigned serial_string_cnt;
 231
 232         unsigned min_hor_freq_hz;
 233         unsigned max_hor_freq_hz;
 234         double min_vert_freq_hz;
 235         double max_vert_freq_hz;
 236         unsigned max_pixclk_khz;
 237         unsigned dtd_max_hsize_mm;
 238         unsigned dtd_max_vsize_mm;
 239
 240         // in 0.1 mm units
 241         unsigned image_width, image_height;
 242         // in inches
 243         double diagonal;
 244
 245         unsigned warnings;
 246         unsigned failures;
 247
 248         // Base block state
 249         struct {
 250                 unsigned edid_minor;
 251                 bool has_name_descriptor;
 252                 bool has_display_range_descriptor;
 253                 unsigned serial_number;
 254                 unsigned char week, year;
 255                 bool supports_continuous_freq;
 256                 bool supports_gtf;
 257                 bool supports_sec_gtf;
 258                 unsigned sec_gtf_start_freq;
 259                 double C, M, K, J;
 260                 bool supports_cvt;
 261                 bool has_spwg;
 262                 bool uses_srgb;
 263                 unsigned detailed_block_cnt;
 264                 unsigned dtd_cnt;
 265                 bool seen_non_detailed_descriptor;
 266                 bool has_640x480p60_est_timing;
 267                 bool preferred_is_also_native;
 268                 timings_ext preferred_timing;
 269
 270                 unsigned min_display_hor_freq_hz;
 271                 unsigned max_display_hor_freq_hz;
 272                 unsigned min_display_vert_freq_hz;
 273                 unsigned max_display_vert_freq_hz;
 274                 unsigned max_display_pixclk_khz;
 275                 unsigned max_display_width_mm;
 276                 unsigned max_display_height_mm;
 277                 unsigned max_pos_neg_hor_freq_khz;
 278         } base;
 279
 280         // CTA-861 block state
 281         struct {
 282                 unsigned preparsed_total_dtds;
 283                 vec_timings_ext vec_dtds;
 284                 unsigned preparsed_total_vtdbs;
 285                 vec_timings_ext vec_vtdbs;
 286                 cta_vfd preparsed_first_vfd;
 287                 vec_timings_ext preferred_timings;
 288                 vec_timings_ext preferred_timings_vfpdb;
 289                 bool preparsed_has_t8vtdb;
 290                 unsigned preparsed_t8vtdb_dmt;
 291                 // Keep track of the found Tag/Extended Tag pairs.
 292                 // The unsigned value is equal to: (tag) | (OUI enum << 12) or (extended tag) | (tag << 8) | (OUI enum << 12)
 293                 std::vector<unsigned> found_tags;
 294                 timings_ext t8vtdb;
 295                 vec_timings_ext native_timings;
 296                 vec_timings_ext native_timing_nvrdb;
 297                 // in 0.1 mm units
 298                 unsigned image_width, image_height;
 299                 bool has_vic_1;
 300                 bool first_svd_might_be_preferred;
 301                 unsigned char byte3;
 302                 bool has_hdmi;
 303                 unsigned hdmi_max_rate;
 304                 bool has_vcdb;
 305                 bool has_vfpdb;
 306                 bool has_nvrdb;
 307                 bool has_cdb;
 308                 unsigned preparsed_speaker_count;
 309                 bool preparsed_sld_has_coord;
 310                 bool preparsed_sld;
 311                 bool has_sldb;
 312                 unsigned short preparsed_phys_addr;
 313                 unsigned previous_cta_tag;
 314                 bool have_hf_vsdb, have_hf_scdb;
 315                 unsigned hf_eeodb_blocks;
 316                 unsigned block_number;
 317                 bool has_svrs;
 318                 bool first_svd;
 319                 unsigned supported_hdmi_vic_codes;
 320                 unsigned supported_hdmi_vic_vsb_codes;
 321                 unsigned short vics[256][2];
 322                 bool preparsed_has_vic[2][256];
 323                 std::vector<unsigned char> preparsed_svds[2];
 324                 unsigned preparsed_max_vic_pixclk_khz;
 325                 bool warn_about_hdmi_2x_dtd;
 326         } cta;
 327
 328         // DisplayID block state
 329         struct {
 330                 unsigned char version;
 331                 unsigned short preparsed_color_ids;
 332                 unsigned short preparsed_xfer_ids;
 333                 unsigned preparsed_displayid_blocks;
 334                 bool is_base_block;
 335                 bool is_display;
 336                 bool has_product_identification;
 337                 bool has_display_parameters;
 338                 bool has_type_1_7;
 339                 bool has_display_interface_features;
 340                 vec_timings_ext preferred_timings;
 341                 unsigned native_width, native_height;
 342                 // in 0.1 mm units
 343                 unsigned image_width, image_height;
 344                 unsigned block_number;
 345                 // Keep track of the found CTA-861 Tag/Extended Tag pairs.
 346                 // The unsigned value is equal to: (tag) | (OUI enum << 12) or (extended tag) | (tag << 8) | (OUI enum << 12)
 347                 std::vector<unsigned> found_tags;
 348         } dispid;
 349
 350         // Block Map block state
 351         struct {
 352                 bool saw_block_1;
 353                 bool saw_block_128;
 354         } block_map;
 355
 356         std::string dtd_type(unsigned dtd);
 357         std::string dtd_type() { return dtd_type(base.dtd_cnt); }
 358         bool print_timings(const char *prefix, const struct timings *t,
 359                            const char *type, const char *flags = "",
 360                            bool detailed = false, bool do_checks = true);
 361         bool print_timings(const char *prefix, const struct timings_ext &t,
 362                            bool detailed = false, bool do_checks = true)
 363         {
 364                 return print_timings(prefix, &t.t, t.type.c_str(), t.flags.c_str(),
 365                                      detailed, do_checks);
 366         };
 367         timings calc_gtf_mode(unsigned h_pixels, unsigned v_lines,
 368                               double ip_freq_rqd, bool int_rqd = false,
 369                               enum gtf_ip_parm ip_parm = gtf_ip_vert_freq,
 370                               bool margins_rqd = false, bool secondary = false,
 371                               double C = 40, double M = 600, double K = 128, double J = 20);
 372         void edid_gtf_mode(unsigned refresh, struct timings &t);
 373         timings calc_cvt_mode(unsigned h_pixels, unsigned v_lines,
 374                               double ip_freq_rqd, unsigned rb, bool int_rqd = false,
 375                               bool margins_rqd = false, bool alt = false,
 376                               unsigned rb_h_blank = 0, unsigned rb_v_blank = 460,
 377                               bool early_vsync_rqd = false);
 378         void edid_cvt_mode(unsigned refresh, struct timings &t, unsigned rb_h_blank = 0,
 379                            unsigned rb_v_blank = 460, bool early_vsync_rqd = false);
 380         void detailed_cvt_descriptor(const char *prefix, const unsigned char *x, bool first);
 381         timings calc_ovt_mode(unsigned hact, unsigned vact,
 382                               unsigned hratio, unsigned vratio,
 383                               unsigned frame_rate);
 384         void print_standard_timing(const char *prefix, unsigned char b1, unsigned char b2,
 385                                    bool gtf_only = false, bool show_both = false);
 386         void detailed_display_range_limits(const unsigned char *x);
 387         void detailed_epi(const unsigned char *x);
 388         void detailed_timings(const char *prefix, const unsigned char *x,
 389                               bool base_or_cta = true);
 390         bool preparse_detailed_block(unsigned char *x);
 391         void preparse_base_block(unsigned char *x);
 392         void detailed_block(const unsigned char *x);
 393         void parse_base_block(const unsigned char *x);
 394         void check_base_block(const unsigned char *x);
 395         void list_dmts();
 396         void list_established_timings();
 397
 398         void data_block_oui(std::string block_name, const unsigned char *x, unsigned length, unsigned *ouinum,
 399                             bool ignorezeros = false, bool do_ascii = false, bool big_endian = false);
 400
 401         void print_vic_index(const char *prefix, unsigned idx, const char *suffix, bool ycbcr420 = false);
 402         void hdmi_latency(unsigned char vid_lat, unsigned char aud_lat, bool is_ilaced);
 403         void cta_vcdb(const unsigned char *x, unsigned length);
 404         void cta_svd(const unsigned char *x, unsigned n, bool for_ycbcr420);
 405         void cta_vfdb(const unsigned char *x, unsigned n);
 406         void cta_y420cmdb(const unsigned char *x, unsigned length);
 407         void cta_print_svr(unsigned char svr, vec_timings_ext &vec_tim);
 408         void cta_vfpdb(const unsigned char *x, unsigned length);
 409         void cta_nvrdb(const unsigned char *x, unsigned length);
 410         cta_vfd cta_parse_vfd(const unsigned char *x, unsigned lvfd);
 411         void cta_rcdb(const unsigned char *x, unsigned length);
 412         void cta_sldb(const unsigned char *x, unsigned length);
 413         void cta_preparse_sldb(const unsigned char *x, unsigned length);
 414         void cta_colorimetry_block(const unsigned char *x, unsigned length);
 415         void cta_hdmi_block(const unsigned char *x, unsigned length);
 416         void cta_hf_scdb(const unsigned char *x, unsigned length);
 417         void cta_displayid_type_7(const unsigned char *x, unsigned length);
 418         void cta_displayid_type_8(const unsigned char *x, unsigned length);
 419         void cta_displayid_type_10(const unsigned char *x, unsigned length);
 420         void cta_block(const unsigned char *x, std::vector<unsigned> &found_tags);
 421         void preparse_cta_block(unsigned char *x);
 422         void parse_cta_block(const unsigned char *x);
 423         void cta_resolve_svr(timings_ext &t_ext);
 424         void cta_resolve_svrs();
 425         void check_cta_blocks();
 426         void cta_list_vics();
 427         void cta_list_hdmi_vics();
 428         void cta_list_rids();
 429         void cta_list_rid_timings(unsigned list_rid = 0);
 430
 431         void set_displayid_native_res(unsigned w, unsigned h);
 432         void parse_digital_interface(const unsigned char *x);
 433         void parse_display_device(const unsigned char *x);
 434         void parse_display_caps(const unsigned char *x);
 435         void parse_display_xfer(const unsigned char *x);
 436         void parse_di_ext_block(const unsigned char *x);
 437
 438         void check_displayid_datablock_revision(unsigned char hdr,
 439                                                 unsigned char valid_flags = 0,
 440                                                 unsigned char rev = 0);
 441         void parse_displayid_product_id(const unsigned char *x);
 442         std::string product_type(unsigned char x, bool heading);
 443         void parse_displayid_interface_features(const unsigned char *x);
 444         void parse_displayid_parameters(const unsigned char *x);
 445         void parse_displayid_parameters_v2(const unsigned char *x, unsigned block_rev);
 446         void parse_displayid_display_intf(const unsigned char *x);
 447         void parse_displayid_color_characteristics(const unsigned char *x);
 448         void parse_displayid_transfer_characteristics(const unsigned char *x);
 449         void parse_displayid_stereo_display_intf(const unsigned char *x);
 450         void parse_displayid_type_1_7_timing(const unsigned char *x,
 451                                              bool type7, unsigned block_rev, bool is_cta = false);
 452         void parse_displayid_type_2_timing(const unsigned char *x);
 453         void parse_displayid_type_3_timing(const unsigned char *x);
 454         void parse_displayid_type_4_8_timing(unsigned char type, unsigned short id, bool is_cta = false);
 455         void parse_displayid_video_timing_range_limits(const unsigned char *x);
 456         void parse_displayid_string(const unsigned char *x);
 457         void parse_displayid_display_device(const unsigned char *x);
 458         void parse_displayid_intf_power_sequencing(const unsigned char *x);
 459         void parse_displayid_type_5_timing(const unsigned char *x);
 460         void parse_displayid_tiled_display_topology(const unsigned char *x, bool is_v2);
 461         void parse_displayid_type_6_timing(const unsigned char *x);
 462         void parse_displayid_type_9_timing(const unsigned char *x);
 463         void parse_displayid_dynamic_video_timings_range_limits(const unsigned char *x);
 464         void parse_displayid_ContainerID(const unsigned char *x);
 465         void parse_displayid_adaptive_sync(const unsigned char *x);
 466         void parse_displayid_type_10_timing(const unsigned char *x, unsigned sz,
 467                                             bool is_cta = false);
 468         void preparse_displayid_block(unsigned char *x);
 469         unsigned displayid_block(const unsigned version, const unsigned char *x, unsigned length);
 470         void parse_displayid_block(const unsigned char *x);
 471         void parse_displayid_vesa(const unsigned char *x);
 472         void parse_displayid_apple(const unsigned char *x);
 473         void parse_displayid_cta_data_block(const unsigned char *x);
 474         void check_displayid_blocks();
 475
 476         void parse_vtb_ext_block(const unsigned char *x);
 477
 478         void parse_string_table(const unsigned char *x);
 479         void preparse_ls_ext_block(unsigned char *x);
 480         void parse_ls_ext_block(const unsigned char *x);
 481
 482         void parse_block_map(const unsigned char *x);
 483
 484         void preparse_extension(unsigned char *x);
 485         void parse_extension(const unsigned char *x);
 486         void print_preferred_timings();
 487         void print_native_res();
 488         int parse_edid();
 489 };
 490
 491 static inline void add_str(std::string &s, const std::string &add)
 492 {
 493         if (s.empty())
 494                 s = add;
 495         else if (!add.empty())
 496                 s = s + ", " + add;
 497 }
 498
 499 void msg(bool is_warn, const char *fmt, ...);
 500
 501 #ifdef _WIN32
 502
 503 #define warn(fmt, ...) msg(true, fmt, __VA_ARGS__)
 504 #define warn_once(fmt, ...)                             \
 505         do {                                            \
 506                 static bool shown_warn;                 \
 507                 if (!shown_warn) {                      \
 508                         shown_warn = true;              \
 509                         msg(true, fmt, __VA_ARGS__);    \
 510                 }                                       \
 511         } while (0)
 512 #define fail(fmt, ...) msg(false, fmt, __VA_ARGS__)
 513
 514 #else
 515
 516 #define warn(fmt, args...) msg(true, fmt, ##args)
 517 #define warn_once(fmt, args...)                         \
 518         do {                                            \
 519                 static bool shown_warn;                 \
 520                 if (!shown_warn) {                      \
 521                         shown_warn = true;              \
 522                         msg(true, fmt, ##args);         \
 523                 }                                       \
 524         } while (0)
 525 #define fail(fmt, args...) msg(false, fmt, ##args)
 526
 527 #endif
 528
 529 std::string utohex(unsigned char x);
 530 std::string ouitohex(unsigned oui);
 531 std::string containerid2s(const unsigned char *x);
 532 bool memchk(const unsigned char *x, unsigned len, unsigned char v = 0);
 533 void hex_block(const char *prefix, const unsigned char *x, unsigned length,
 534                bool show_ascii = true, unsigned step = 16);
 535 std::string block_name(unsigned char block);
 536 void do_checksum(const char *prefix, const unsigned char *x, size_t len, unsigned unused_bytes = 0);
 537 void replace_checksum(unsigned char *x, size_t len);
 538 void calc_ratio(struct timings *t);
 539 const char *oui_name(unsigned oui, unsigned *ouinum = NULL);
 540 unsigned gcd(unsigned a, unsigned b);
 541
 542 bool match_timings(const timings &t1, const timings &t2);
 543 bool timings_close_match(const timings &t1, const timings &t2);
 544 const struct timings *find_dmt_id(unsigned char dmt_id);
 545 const struct timings *close_match_to_dmt(const timings &t, unsigned &dmt);
 546 const struct timings *find_vic_id(unsigned char vic);
 547 const struct cta_rid *find_rid(unsigned char rid);
 548 const struct timings *find_hdmi_vic_id(unsigned char hdmi_vic);
 549 const struct timings *cta_close_match_to_vic(const timings &t, unsigned &vic);
 550 bool cta_matches_vic(const timings &t, unsigned &vic);
 551 unsigned char hdmi_vic_to_vic(unsigned char hdmi_vic);
 552 char *extract_string(const unsigned char *x, unsigned len);
 553
 554 #define oneoui(c,k,n) const unsigned kOUI_##k = __LINE__<<12;
 555 #include "oui.h"
 556
 557 #endif