DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Mercurial (56e7b9127e89)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982
/*
 * Copyright (c) 2016, Alliance for Open Media. All rights reserved
 *
 * This source code is subject to the terms of the BSD 2 Clause License and
 * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
 * was not distributed with this source code in the LICENSE file, you can
 * obtain it at www.aomedia.org/license/software. If the Alliance for Open
 * Media Patent License 1.0 was not distributed with this source code in the
 * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
 */
#ifndef AOM_AOM_ENCODER_H_
#define AOM_AOM_ENCODER_H_

/*!\defgroup encoder Encoder Algorithm Interface
 * \ingroup codec
 * This abstraction allows applications using this encoder to easily support
 * multiple video formats with minimal code duplication. This section describes
 * the interface common to all encoders.
 * @{
 */

/*!\file
 * \brief Describes the encoder algorithm interface to applications.
 *
 * This file describes the interface between an application and a
 * video encoder algorithm.
 *
 */
#ifdef __cplusplus
extern "C" {
#endif

#include "aom/aom_codec.h"

/*!\brief Current ABI version number
 *
 * \internal
 * If this file is altered in any way that changes the ABI, this value
 * must be bumped.  Examples include, but are not limited to, changing
 * types, removing or reassigning enums, adding/removing/rearranging
 * fields to structures
 */
#define AOM_ENCODER_ABI_VERSION \
  (5 + AOM_CODEC_ABI_VERSION) /**<\hideinitializer*/

/*! \brief Encoder capabilities bitfield
 *
 *  Each encoder advertises the capabilities it supports as part of its
 *  ::aom_codec_iface_t interface structure. Capabilities are extra
 *  interfaces or functionality, and are not required to be supported
 *  by an encoder.
 *
 *  The available flags are specified by AOM_CODEC_CAP_* defines.
 */
#define AOM_CODEC_CAP_PSNR 0x10000 /**< Can issue PSNR packets */

/*! Can output one partition at a time. Each partition is returned in its
 *  own AOM_CODEC_CX_FRAME_PKT, with the FRAME_IS_FRAGMENT flag set for
 *  every partition but the last. In this mode all frames are always
 *  returned partition by partition.
 */
#define AOM_CODEC_CAP_OUTPUT_PARTITION 0x20000

/*! Can support input images at greater than 8 bitdepth.
 */
#define AOM_CODEC_CAP_HIGHBITDEPTH 0x40000

/*! \brief Initialization-time Feature Enabling
 *
 *  Certain codec features must be known at initialization time, to allow
 *  for proper memory allocation.
 *
 *  The available flags are specified by AOM_CODEC_USE_* defines.
 */
#define AOM_CODEC_USE_PSNR 0x10000 /**< Calculate PSNR on each frame */
/*!\brief Make the encoder output one  partition at a time. */
#define AOM_CODEC_USE_OUTPUT_PARTITION 0x20000
#define AOM_CODEC_USE_HIGHBITDEPTH 0x40000 /**< Use high bitdepth */

/*!\brief Generic fixed size buffer structure
 *
 * This structure is able to hold a reference to any fixed size buffer.
 */
typedef struct aom_fixed_buf {
  void *buf;       /**< Pointer to the data */
  size_t sz;       /**< Length of the buffer, in chars */
} aom_fixed_buf_t; /**< alias for struct aom_fixed_buf */

/*!\brief Time Stamp Type
 *
 * An integer, which when multiplied by the stream's time base, provides
 * the absolute time of a sample.
 */
typedef int64_t aom_codec_pts_t;

/*!\brief Compressed Frame Flags
 *
 * This type represents a bitfield containing information about a compressed
 * frame that may be useful to an application. The most significant 16 bits
 * can be used by an algorithm to provide additional detail, for example to
 * support frame types that are codec specific (MPEG-1 D-frames for example)
 */
typedef uint32_t aom_codec_frame_flags_t;
#define AOM_FRAME_IS_KEY 0x1 /**< frame is the start of a GOP */
/*!\brief frame can be dropped without affecting the stream (no future frame
 * depends on this one) */
#define AOM_FRAME_IS_DROPPABLE 0x2
/*!\brief frame should be decoded but will not be shown */
#define AOM_FRAME_IS_INVISIBLE 0x4
/*!\brief this is a fragment of the encoded frame */
#define AOM_FRAME_IS_FRAGMENT 0x8

/*!\brief Error Resilient flags
 *
 * These flags define which error resilient features to enable in the
 * encoder. The flags are specified through the
 * aom_codec_enc_cfg::g_error_resilient variable.
 */
typedef uint32_t aom_codec_er_flags_t;
/*!\brief Improve resiliency against losses of whole frames */
#define AOM_ERROR_RESILIENT_DEFAULT 0x1
/*!\brief The frame partitions are independently decodable by the bool decoder,
 * meaning that partitions can be decoded even though earlier partitions have
 * been lost. Note that intra prediction is still done over the partition
 * boundary. */
#define AOM_ERROR_RESILIENT_PARTITIONS 0x2

/*!\brief Encoder output packet variants
 *
 * This enumeration lists the different kinds of data packets that can be
 * returned by calls to aom_codec_get_cx_data(). Algorithms \ref MAY
 * extend this list to provide additional functionality.
 */
enum aom_codec_cx_pkt_kind {
  AOM_CODEC_CX_FRAME_PKT,    /**< Compressed video frame */
  AOM_CODEC_STATS_PKT,       /**< Two-pass statistics for this frame */
  AOM_CODEC_FPMB_STATS_PKT,  /**< first pass mb statistics for this frame */
  AOM_CODEC_PSNR_PKT,        /**< PSNR statistics for this frame */
  AOM_CODEC_CUSTOM_PKT = 256 /**< Algorithm extensions  */
};

/*!\brief Encoder output packet
 *
 * This structure contains the different kinds of output data the encoder
 * may produce while compressing a frame.
 */
typedef struct aom_codec_cx_pkt {
  enum aom_codec_cx_pkt_kind kind; /**< packet variant */
  union {
    struct {
      void *buf; /**< compressed data buffer */
      size_t sz; /**< length of compressed data */
      /*!\brief time stamp to show frame (in timebase units) */
      aom_codec_pts_t pts;
      /*!\brief duration to show frame (in timebase units) */
      unsigned long duration;
      aom_codec_frame_flags_t flags; /**< flags for this frame */
      /*!\brief the partition id defines the decoding order of the partitions.
       * Only applicable when "output partition" mode is enabled. First
       * partition has id 0.*/
      int partition_id;
      /*!\brief size of the visible frame in this packet */
      size_t vis_frame_size;
    } frame;                            /**< data for compressed frame packet */
    aom_fixed_buf_t twopass_stats;      /**< data for two-pass packet */
    aom_fixed_buf_t firstpass_mb_stats; /**< first pass mb packet */
    struct aom_psnr_pkt {
      unsigned int samples[4]; /**< Number of samples, total/y/u/v */
      uint64_t sse[4];         /**< sum squared error, total/y/u/v */
      double psnr[4];          /**< PSNR, total/y/u/v */
    } psnr;                    /**< data for PSNR packet */
    aom_fixed_buf_t raw;       /**< data for arbitrary packets */

    /* This packet size is fixed to allow codecs to extend this
     * interface without having to manage storage for raw packets,
     * i.e., if it's smaller than 128 bytes, you can store in the
     * packet list directly.
     */
    char pad[128 - sizeof(enum aom_codec_cx_pkt_kind)]; /**< fixed sz */
  } data;                                               /**< packet data */
} aom_codec_cx_pkt_t; /**< alias for struct aom_codec_cx_pkt */

/*!\brief Rational Number
 *
 * This structure holds a fractional value.
 */
typedef struct aom_rational {
  int num;        /**< fraction numerator */
  int den;        /**< fraction denominator */
} aom_rational_t; /**< alias for struct aom_rational */

/*!\brief Multi-pass Encoding Pass */
enum aom_enc_pass {
  AOM_RC_ONE_PASS,   /**< Single pass mode */
  AOM_RC_FIRST_PASS, /**< First pass of multi-pass mode */
  AOM_RC_LAST_PASS   /**< Final pass of multi-pass mode */
};

/*!\brief Rate control mode */
enum aom_rc_mode {
  AOM_VBR, /**< Variable Bit Rate (VBR) mode */
  AOM_CBR, /**< Constant Bit Rate (CBR) mode */
  AOM_CQ,  /**< Constrained Quality (CQ)  mode */
  AOM_Q,   /**< Constant Quality (Q) mode */
};

/*!\brief Keyframe placement mode.
 *
 * This enumeration determines whether keyframes are placed automatically by
 * the encoder or whether this behavior is disabled. Older releases of this
 * SDK were implemented such that AOM_KF_FIXED meant keyframes were disabled.
 * This name is confusing for this behavior, so the new symbols to be used
 * are AOM_KF_AUTO and AOM_KF_DISABLED.
 */
enum aom_kf_mode {
  AOM_KF_FIXED,       /**< deprecated, implies AOM_KF_DISABLED */
  AOM_KF_AUTO,        /**< Encoder determines optimal placement automatically */
  AOM_KF_DISABLED = 0 /**< Encoder does not place keyframes. */
};

/*!\brief Encoded Frame Flags
 *
 * This type indicates a bitfield to be passed to aom_codec_encode(), defining
 * per-frame boolean values. By convention, bits common to all codecs will be
 * named AOM_EFLAG_*, and bits specific to an algorithm will be named
 * /algo/_eflag_*. The lower order 16 bits are reserved for common use.
 */
typedef long aom_enc_frame_flags_t;
#define AOM_EFLAG_FORCE_KF (1 << 0) /**< Force this frame to be a keyframe */

/*!\brief Encoder configuration structure
 *
 * This structure contains the encoder settings that have common representations
 * across all codecs. This doesn't imply that all codecs support all features,
 * however.
 */
typedef struct aom_codec_enc_cfg {
  /*
   * generic settings (g)
   */

  /*!\brief Algorithm specific "usage" value
   *
   * Algorithms may define multiple values for usage, which may convey the
   * intent of how the application intends to use the stream. If this value
   * is non-zero, consult the documentation for the codec to determine its
   * meaning.
   */
  unsigned int g_usage;

  /*!\brief Maximum number of threads to use
   *
   * For multi-threaded implementations, use no more than this number of
   * threads. The codec may use fewer threads than allowed. The value
   * 0 is equivalent to the value 1.
   */
  unsigned int g_threads;

  /*!\brief Bitstream profile to use
   *
   * Some codecs support a notion of multiple bitstream profiles. Typically
   * this maps to a set of features that are turned on or off. Often the
   * profile to use is determined by the features of the intended decoder.
   * Consult the documentation for the codec to determine the valid values
   * for this parameter, or set to zero for a sane default.
   */
  unsigned int g_profile; /**< profile of bitstream to use */

  /*!\brief Width of the frame
   *
   * This value identifies the presentation resolution of the frame,
   * in pixels. Note that the frames passed as input to the encoder must
   * have this resolution. Frames will be presented by the decoder in this
   * resolution, independent of any spatial resampling the encoder may do.
   */
  unsigned int g_w;

  /*!\brief Height of the frame
   *
   * This value identifies the presentation resolution of the frame,
   * in pixels. Note that the frames passed as input to the encoder must
   * have this resolution. Frames will be presented by the decoder in this
   * resolution, independent of any spatial resampling the encoder may do.
   */
  unsigned int g_h;

  /*!\brief Max number of frames to encode
   *
   */
  unsigned int g_limit;

  /*!\brief Forced maximum width of the frame
   *
   * If this value is non-zero then it is used to force the maximum frame
   * width written in write_sequence_header().
   */
  unsigned int g_forced_max_frame_width;

  /*!\brief Forced maximum height of the frame
   *
   * If this value is non-zero then it is used to force the maximum frame
   * height written in write_sequence_header().
   */
  unsigned int g_forced_max_frame_height;

  /*!\brief Bit-depth of the codec
   *
   * This value identifies the bit_depth of the codec,
   * Only certain bit-depths are supported as identified in the
   * aom_bit_depth_t enum.
   */
  aom_bit_depth_t g_bit_depth;

  /*!\brief Bit-depth of the input frames
   *
   * This value identifies the bit_depth of the input frames in bits.
   * Note that the frames passed as input to the encoder must have
   * this bit-depth.
   */
  unsigned int g_input_bit_depth;

  /*!\brief Stream timebase units
   *
   * Indicates the smallest interval of time, in seconds, used by the stream.
   * For fixed frame rate material, or variable frame rate material where
   * frames are timed at a multiple of a given clock (ex: video capture),
   * the \ref RECOMMENDED method is to set the timebase to the reciprocal
   * of the frame rate (ex: 1001/30000 for 29.970 Hz NTSC). This allows the
   * pts to correspond to the frame number, which can be handy. For
   * re-encoding video from containers with absolute time timestamps, the
   * \ref RECOMMENDED method is to set the timebase to that of the parent
   * container or multimedia framework (ex: 1/1000 for ms, as in FLV).
   */
  struct aom_rational g_timebase;

  /*!\brief Enable error resilient modes.
   *
   * The error resilient bitfield indicates to the encoder which features
   * it should enable to take measures for streaming over lossy or noisy
   * links.
   */
  aom_codec_er_flags_t g_error_resilient;

  /*!\brief Multi-pass Encoding Mode
   *
   * This value should be set to the current phase for multi-pass encoding.
   * For single pass, set to #AOM_RC_ONE_PASS.
   */
  enum aom_enc_pass g_pass;

  /*!\brief Allow lagged encoding
   *
   * If set, this value allows the encoder to consume a number of input
   * frames before producing output frames. This allows the encoder to
   * base decisions for the current frame on future frames. This does
   * increase the latency of the encoding pipeline, so it is not appropriate
   * in all situations (ex: realtime encoding).
   *
   * Note that this is a maximum value -- the encoder may produce frames
   * sooner than the given limit. Set this value to 0 to disable this
   * feature.
   */
  unsigned int g_lag_in_frames;

  /*
   * rate control settings (rc)
   */

  /*!\brief Temporal resampling configuration, if supported by the codec.
   *
   * Temporal resampling allows the codec to "drop" frames as a strategy to
   * meet its target data rate. This can cause temporal discontinuities in
   * the encoded video, which may appear as stuttering during playback. This
   * trade-off is often acceptable, but for many applications is not. It can
   * be disabled in these cases.
   *
   * Note that not all codecs support this feature. All aom AVx codecs do.
   * For other codecs, consult the documentation for that algorithm.
   *
   * This threshold is described as a percentage of the target data buffer.
   * When the data buffer falls below this percentage of fullness, a
   * dropped frame is indicated. Set the threshold to zero (0) to disable
   * this feature.
   */
  unsigned int rc_dropframe_thresh;

  /*!\brief Mode for spatial resampling, if supported by the codec.
   *
   * Spatial resampling allows the codec to compress a lower resolution
   * version of the frame, which is then upscaled by the decoder to the
   * correct presentation resolution. This increases visual quality at
   * low data rates, at the expense of CPU time on the encoder/decoder.
   */
  unsigned int rc_resize_mode;

  /*!\brief Frame resize denominator.
   *
   * The denominator for resize to use, assuming 8 as the numerator.
   *
   * Valid denominators are  8 - 16 for now.
   */
  unsigned int rc_resize_denominator;

  /*!\brief Keyframe resize denominator.
   *
   * The denominator for resize to use, assuming 8 as the numerator.
   *
   * Valid denominators are  8 - 16 for now.
   */
  unsigned int rc_resize_kf_denominator;

  /*!\brief Frame super-resolution scaling mode.
   *
   * Similar to spatial resampling, frame super-resolution integrates
   * upscaling after the encode/decode process. Taking control of upscaling and
   * using restoration filters should allow it to outperform normal resizing.
   *
   * Mode 0 is SUPERRES_NONE, mode 1 is SUPERRES_FIXED, mode 2 is
   * SUPERRES_RANDOM and mode 3 is SUPERRES_QTHRESH.
   */
  unsigned int rc_superres_mode;

  /*!\brief Frame super-resolution denominator.
   *
   * The denominator for superres to use. If fixed it will only change if the
   * cumulative scale change over resizing and superres is greater than 1/2;
   * this forces superres to reduce scaling.
   *
   * Valid denominators are 8 to 16.
   *
   * Used only by SUPERRES_FIXED.
   */
  unsigned int rc_superres_denominator;

  /*!\brief Keyframe super-resolution denominator.
   *
   * The denominator for superres to use. If fixed it will only change if the
   * cumulative scale change over resizing and superres is greater than 1/2;
   * this forces superres to reduce scaling.
   *
   * Valid denominators are 8 - 16 for now.
   */
  unsigned int rc_superres_kf_denominator;

  /*!\brief Frame super-resolution q threshold.
   *
   * The q level threshold after which superres is used.
   * Valid values are 1 to 63.
   *
   * Used only by SUPERRES_QTHRESH
   */
  unsigned int rc_superres_qthresh;

  /*!\brief Keyframe super-resolution q threshold.
   *
   * The q level threshold after which superres is used for key frames.
   * Valid values are 1 to 63.
   *
   * Used only by SUPERRES_QTHRESH
   */
  unsigned int rc_superres_kf_qthresh;

  /*!\brief Rate control algorithm to use.
   *
   * Indicates whether the end usage of this stream is to be streamed over
   * a bandwidth constrained link, indicating that Constant Bit Rate (CBR)
   * mode should be used, or whether it will be played back on a high
   * bandwidth link, as from a local disk, where higher variations in
   * bitrate are acceptable.
   */
  enum aom_rc_mode rc_end_usage;

  /*!\brief Two-pass stats buffer.
   *
   * A buffer containing all of the stats packets produced in the first
   * pass, concatenated.
   */
  aom_fixed_buf_t rc_twopass_stats_in;

  /*!\brief first pass mb stats buffer.
   *
   * A buffer containing all of the first pass mb stats packets produced
   * in the first pass, concatenated.
   */
  aom_fixed_buf_t rc_firstpass_mb_stats_in;

  /*!\brief Target data rate
   *
   * Target bandwidth to use for this stream, in kilobits per second.
   */
  unsigned int rc_target_bitrate;

  /*
   * quantizer settings
   */

  /*!\brief Minimum (Best Quality) Quantizer
   *
   * The quantizer is the most direct control over the quality of the
   * encoded image. The range of valid values for the quantizer is codec
   * specific. Consult the documentation for the codec to determine the
   * values to use. To determine the range programmatically, call
   * aom_codec_enc_config_default() with a usage value of 0.
   */
  unsigned int rc_min_quantizer;

  /*!\brief Maximum (Worst Quality) Quantizer
   *
   * The quantizer is the most direct control over the quality of the
   * encoded image. The range of valid values for the quantizer is codec
   * specific. Consult the documentation for the codec to determine the
   * values to use. To determine the range programmatically, call
   * aom_codec_enc_config_default() with a usage value of 0.
   */
  unsigned int rc_max_quantizer;

  /*
   * bitrate tolerance
   */

  /*!\brief Rate control adaptation undershoot control
   *
   * This value, expressed as a percentage of the target bitrate,
   * controls the maximum allowed adaptation speed of the codec.
   * This factor controls the maximum amount of bits that can
   * be subtracted from the target bitrate in order to compensate
   * for prior overshoot.
   *
   * Valid values in the range 0-1000.
   */
  unsigned int rc_undershoot_pct;

  /*!\brief Rate control adaptation overshoot control
   *
   * This value, expressed as a percentage of the target bitrate,
   * controls the maximum allowed adaptation speed of the codec.
   * This factor controls the maximum amount of bits that can
   * be added to the target bitrate in order to compensate for
   * prior undershoot.
   *
   * Valid values in the range 0-1000.
   */
  unsigned int rc_overshoot_pct;

  /*
   * decoder buffer model parameters
   */

  /*!\brief Decoder Buffer Size
   *
   * This value indicates the amount of data that may be buffered by the
   * decoding application. Note that this value is expressed in units of
   * time (milliseconds). For example, a value of 5000 indicates that the
   * client will buffer (at least) 5000ms worth of encoded data. Use the
   * target bitrate (#rc_target_bitrate) to convert to bits/bytes, if
   * necessary.
   */
  unsigned int rc_buf_sz;

  /*!\brief Decoder Buffer Initial Size
   *
   * This value indicates the amount of data that will be buffered by the
   * decoding application prior to beginning playback. This value is
   * expressed in units of time (milliseconds). Use the target bitrate
   * (#rc_target_bitrate) to convert to bits/bytes, if necessary.
   */
  unsigned int rc_buf_initial_sz;

  /*!\brief Decoder Buffer Optimal Size
   *
   * This value indicates the amount of data that the encoder should try
   * to maintain in the decoder's buffer. This value is expressed in units
   * of time (milliseconds). Use the target bitrate (#rc_target_bitrate)
   * to convert to bits/bytes, if necessary.
   */
  unsigned int rc_buf_optimal_sz;

  /*
   * 2 pass rate control parameters
   */

  /*!\brief Two-pass mode CBR/VBR bias
   *
   * Bias, expressed on a scale of 0 to 100, for determining target size
   * for the current frame. The value 0 indicates the optimal CBR mode
   * value should be used. The value 100 indicates the optimal VBR mode
   * value should be used. Values in between indicate which way the
   * encoder should "lean."
   */
  unsigned int rc_2pass_vbr_bias_pct;

  /*!\brief Two-pass mode per-GOP minimum bitrate
   *
   * This value, expressed as a percentage of the target bitrate, indicates
   * the minimum bitrate to be used for a single GOP (aka "section")
   */
  unsigned int rc_2pass_vbr_minsection_pct;

  /*!\brief Two-pass mode per-GOP maximum bitrate
   *
   * This value, expressed as a percentage of the target bitrate, indicates
   * the maximum bitrate to be used for a single GOP (aka "section")
   */
  unsigned int rc_2pass_vbr_maxsection_pct;

  /*
   * keyframing settings (kf)
   */

  /*!\brief Option to enable forward reference key frame
   *
   */
  int fwd_kf_enabled;

  /*!\brief Keyframe placement mode
   *
   * This value indicates whether the encoder should place keyframes at a
   * fixed interval, or determine the optimal placement automatically
   * (as governed by the #kf_min_dist and #kf_max_dist parameters)
   */
  enum aom_kf_mode kf_mode;

  /*!\brief Keyframe minimum interval
   *
   * This value, expressed as a number of frames, prevents the encoder from
   * placing a keyframe nearer than kf_min_dist to the previous keyframe. At
   * least kf_min_dist frames non-keyframes will be coded before the next
   * keyframe. Set kf_min_dist equal to kf_max_dist for a fixed interval.
   */
  unsigned int kf_min_dist;

  /*!\brief Keyframe maximum interval
   *
   * This value, expressed as a number of frames, forces the encoder to code
   * a keyframe if one has not been coded in the last kf_max_dist frames.
   * A value of 0 implies all frames will be keyframes. Set kf_min_dist
   * equal to kf_max_dist for a fixed interval.
   */
  unsigned int kf_max_dist;

  /*!\brief sframe interval
   *
   * This value, expressed as a number of frames, forces the encoder to code
   * an S-Frame every sframe_dist frames.
   */
  unsigned int sframe_dist;

  /*!\brief sframe insertion mode
   *
   * This value must be set to 1 or 2, and tells the encoder how to insert
   * S-Frames. It will only have an effect if sframe_dist != 0.
   *
   * If altref is enabled:
   *   - if sframe_mode == 1, the considered frame will be made into an
   *     S-Frame only if it is an altref frame
   *   - if sframe_mode == 2, the next altref frame will be made into an
   *     S-Frame.
   *
   * Otherwise: the considered frame will be made into an S-Frame.
   */
  unsigned int sframe_mode;

  /*!\brief Tile coding mode
   *
   * This value indicates the tile coding mode.
   * A value of 0 implies a normal non-large-scale tile coding. A value of 1
   * implies a large-scale tile coding.
   */
  unsigned int large_scale_tile;

  /*!\brief Monochrome mode
   *
   * If this is nonzero, the encoder will generate a monochrome stream
   * with no chroma planes.
   */
  unsigned int monochrome;

  /*!\brief full_still_picture_hdr
   *
   * If this is nonzero, the encoder will generate a full header even for
   * still picture encoding. if zero, a reduced header is used for still
   * picture. This flag has no effect when a regular video with more than
   * a single frame is encoded.
   */
  unsigned int full_still_picture_hdr;

  /*!\brief Bitstream syntax mode
   *
   * This value indicates the bitstream syntax mode.
   * A value of 0 indicates bitstream is saved as Section 5 bitstream. A value
   * of 1 indicates the bitstream is saved in Annex-B format
   */
  unsigned int save_as_annexb;

  /*!\brief Number of explicit tile widths specified
   *
   * This value indicates the number of tile widths specified
   * A value of 0 implies no tile widths are specified.
   * Tile widths are given in the array tile_widths[]
   */
  int tile_width_count;

  /*!\brief Number of explicit tile heights specified
   *
   * This value indicates the number of tile heights specified
   * A value of 0 implies no tile heights are specified.
   * Tile heights are given in the array tile_heights[]
   */
  int tile_height_count;

/*!\brief Maximum number of tile widths in tile widths array
 *
 * This define gives the maximum number of elements in the tile_widths array.
 */
#define MAX_TILE_WIDTHS 64  // maximum tile width array length

  /*!\brief Array of specified tile widths
   *
   * This array specifies tile widths (and may be empty)
   * The number of widths specified is given by tile_width_count
   */
  int tile_widths[MAX_TILE_WIDTHS];

/*!\brief Maximum number of tile heights in tile heights array.
 *
 * This define gives the maximum number of elements in the tile_heights array.
 */
#define MAX_TILE_HEIGHTS 64  // maximum tile height array length

  /*!\brief Array of specified tile heights
   *
   * This array specifies tile heights (and may be empty)
   * The number of heights specified is given by tile_height_count
   */
  int tile_heights[MAX_TILE_HEIGHTS];

  /*!\brief Options defined per config file
   *
   */
  cfg_options_t cfg;
} aom_codec_enc_cfg_t; /**< alias for struct aom_codec_enc_cfg */

/*!\brief Initialize an encoder instance
 *
 * Initializes a encoder context using the given interface. Applications
 * should call the aom_codec_enc_init convenience macro instead of this
 * function directly, to ensure that the ABI version number parameter
 * is properly initialized.
 *
 * If the library was configured with --disable-multithread, this call
 * is not thread safe and should be guarded with a lock if being used
 * in a multithreaded context.
 *
 * \param[in]    ctx     Pointer to this instance's context.
 * \param[in]    iface   Pointer to the algorithm interface to use.
 * \param[in]    cfg     Configuration to use, if known.
 * \param[in]    flags   Bitfield of AOM_CODEC_USE_* flags
 * \param[in]    ver     ABI version number. Must be set to
 *                       AOM_ENCODER_ABI_VERSION
 * \retval #AOM_CODEC_OK
 *     The decoder algorithm initialized.
 * \retval #AOM_CODEC_MEM_ERROR
 *     Memory allocation failed.
 */
aom_codec_err_t aom_codec_enc_init_ver(aom_codec_ctx_t *ctx,
                                       aom_codec_iface_t *iface,
                                       const aom_codec_enc_cfg_t *cfg,
                                       aom_codec_flags_t flags, int ver);

/*!\brief Convenience macro for aom_codec_enc_init_ver()
 *
 * Ensures the ABI version parameter is properly set.
 */
#define aom_codec_enc_init(ctx, iface, cfg, flags) \
  aom_codec_enc_init_ver(ctx, iface, cfg, flags, AOM_ENCODER_ABI_VERSION)

/*!\brief Initialize multi-encoder instance
 *
 * Initializes multi-encoder context using the given interface.
 * Applications should call the aom_codec_enc_init_multi convenience macro
 * instead of this function directly, to ensure that the ABI version number
 * parameter is properly initialized.
 *
 * \param[in]    ctx     Pointer to this instance's context.
 * \param[in]    iface   Pointer to the algorithm interface to use.
 * \param[in]    cfg     Configuration to use, if known.
 * \param[in]    num_enc Total number of encoders.
 * \param[in]    flags   Bitfield of AOM_CODEC_USE_* flags
 * \param[in]    dsf     Pointer to down-sampling factors.
 * \param[in]    ver     ABI version number. Must be set to
 *                       AOM_ENCODER_ABI_VERSION
 * \retval #AOM_CODEC_OK
 *     The decoder algorithm initialized.
 * \retval #AOM_CODEC_MEM_ERROR
 *     Memory allocation failed.
 */
aom_codec_err_t aom_codec_enc_init_multi_ver(
    aom_codec_ctx_t *ctx, aom_codec_iface_t *iface, aom_codec_enc_cfg_t *cfg,
    int num_enc, aom_codec_flags_t flags, aom_rational_t *dsf, int ver);

/*!\brief Convenience macro for aom_codec_enc_init_multi_ver()
 *
 * Ensures the ABI version parameter is properly set.
 */
#define aom_codec_enc_init_multi(ctx, iface, cfg, num_enc, flags, dsf) \
  aom_codec_enc_init_multi_ver(ctx, iface, cfg, num_enc, flags, dsf,   \
                               AOM_ENCODER_ABI_VERSION)

/*!\brief Get a default configuration
 *
 * Initializes a encoder configuration structure with default values. Supports
 * the notion of "usages" so that an algorithm may offer different default
 * settings depending on the user's intended goal. This function \ref SHOULD
 * be called by all applications to initialize the configuration structure
 * before specializing the configuration with application specific values.
 *
 * \param[in]    iface     Pointer to the algorithm interface to use.
 * \param[out]   cfg       Configuration buffer to populate.
 * \param[in]    reserved  Must set to 0.
 *
 * \retval #AOM_CODEC_OK
 *     The configuration was populated.
 * \retval #AOM_CODEC_INCAPABLE
 *     Interface is not an encoder interface.
 * \retval #AOM_CODEC_INVALID_PARAM
 *     A parameter was NULL, or the usage value was not recognized.
 */
aom_codec_err_t aom_codec_enc_config_default(aom_codec_iface_t *iface,
                                             aom_codec_enc_cfg_t *cfg,
                                             unsigned int reserved);

/*!\brief Set or change configuration
 *
 * Reconfigures an encoder instance according to the given configuration.
 *
 * \param[in]    ctx     Pointer to this instance's context
 * \param[in]    cfg     Configuration buffer to use
 *
 * \retval #AOM_CODEC_OK
 *     The configuration was populated.
 * \retval #AOM_CODEC_INCAPABLE
 *     Interface is not an encoder interface.
 * \retval #AOM_CODEC_INVALID_PARAM
 *     A parameter was NULL, or the usage value was not recognized.
 */
aom_codec_err_t aom_codec_enc_config_set(aom_codec_ctx_t *ctx,
                                         const aom_codec_enc_cfg_t *cfg);

/*!\brief Get global stream headers
 *
 * Retrieves a stream level global header packet, if supported by the codec.
 *
 * \param[in]    ctx     Pointer to this instance's context
 *
 * \retval NULL
 *     Encoder does not support global header
 * \retval Non-NULL
 *     Pointer to buffer containing global header packet
 */
aom_fixed_buf_t *aom_codec_get_global_headers(aom_codec_ctx_t *ctx);

/*!\brief Encode a frame
 *
 * Encodes a video frame at the given "presentation time." The presentation
 * time stamp (PTS) \ref MUST be strictly increasing.
 *
 * When the last frame has been passed to the encoder, this function should
 * continue to be called, with the img parameter set to NULL. This will
 * signal the end-of-stream condition to the encoder and allow it to encode
 * any held buffers. Encoding is complete when aom_codec_encode() is called
 * and aom_codec_get_cx_data() returns no data.
 *
 * \param[in]    ctx       Pointer to this instance's context
 * \param[in]    img       Image data to encode, NULL to flush.
 * \param[in]    pts       Presentation time stamp, in timebase units.
 * \param[in]    duration  Duration to show frame, in timebase units.
 * \param[in]    flags     Flags to use for encoding this frame.
 *
 * \retval #AOM_CODEC_OK
 *     The configuration was populated.
 * \retval #AOM_CODEC_INCAPABLE
 *     Interface is not an encoder interface.
 * \retval #AOM_CODEC_INVALID_PARAM
 *     A parameter was NULL, the image format is unsupported, etc.
 */
aom_codec_err_t aom_codec_encode(aom_codec_ctx_t *ctx, const aom_image_t *img,
                                 aom_codec_pts_t pts, unsigned long duration,
                                 aom_enc_frame_flags_t flags);

/*!\brief Set compressed data output buffer
 *
 * Sets the buffer that the codec should output the compressed data
 * into. This call effectively sets the buffer pointer returned in the
 * next AOM_CODEC_CX_FRAME_PKT packet. Subsequent packets will be
 * appended into this buffer. The buffer is preserved across frames,
 * so applications must periodically call this function after flushing
 * the accumulated compressed data to disk or to the network to reset
 * the pointer to the buffer's head.
 *
 * `pad_before` bytes will be skipped before writing the compressed
 * data, and `pad_after` bytes will be appended to the packet. The size
 * of the packet will be the sum of the size of the actual compressed
 * data, pad_before, and pad_after. The padding bytes will be preserved
 * (not overwritten).
 *
 * Note that calling this function does not guarantee that the returned
 * compressed data will be placed into the specified buffer. In the
 * event that the encoded data will not fit into the buffer provided,
 * the returned packet \ref MAY point to an internal buffer, as it would
 * if this call were never used. In this event, the output packet will
 * NOT have any padding, and the application must free space and copy it
 * to the proper place. This is of particular note in configurations
 * that may output multiple packets for a single encoded frame (e.g., lagged
 * encoding) or if the application does not reset the buffer periodically.
 *
 * Applications may restore the default behavior of the codec providing
 * the compressed data buffer by calling this function with a NULL
 * buffer.
 *
 * Applications \ref MUSTNOT call this function during iteration of
 * aom_codec_get_cx_data().
 *
 * \param[in]    ctx         Pointer to this instance's context
 * \param[in]    buf         Buffer to store compressed data into
 * \param[in]    pad_before  Bytes to skip before writing compressed data
 * \param[in]    pad_after   Bytes to skip after writing compressed data
 *
 * \retval #AOM_CODEC_OK
 *     The buffer was set successfully.
 * \retval #AOM_CODEC_INVALID_PARAM
 *     A parameter was NULL, the image format is unsupported, etc.
 */
aom_codec_err_t aom_codec_set_cx_data_buf(aom_codec_ctx_t *ctx,
                                          const aom_fixed_buf_t *buf,
                                          unsigned int pad_before,
                                          unsigned int pad_after);

/*!\brief Encoded data iterator
 *
 * Iterates over a list of data packets to be passed from the encoder to the
 * application. The different kinds of packets available are enumerated in
 * #aom_codec_cx_pkt_kind.
 *
 * #AOM_CODEC_CX_FRAME_PKT packets should be passed to the application's
 * muxer. Multiple compressed frames may be in the list.
 * #AOM_CODEC_STATS_PKT packets should be appended to a global buffer.
 *
 * The application \ref MUST silently ignore any packet kinds that it does
 * not recognize or support.
 *
 * The data buffers returned from this function are only guaranteed to be
 * valid until the application makes another call to any aom_codec_* function.
 *
 * \param[in]     ctx      Pointer to this instance's context
 * \param[in,out] iter     Iterator storage, initialized to NULL
 *
 * \return Returns a pointer to an output data packet (compressed frame data,
 *         two-pass statistics, etc.) or NULL to signal end-of-list.
 *
 */
const aom_codec_cx_pkt_t *aom_codec_get_cx_data(aom_codec_ctx_t *ctx,
                                                aom_codec_iter_t *iter);

/*!\brief Get Preview Frame
 *
 * Returns an image that can be used as a preview. Shows the image as it would
 * exist at the decompressor. The application \ref MUST NOT write into this
 * image buffer.
 *
 * \param[in]     ctx      Pointer to this instance's context
 *
 * \return Returns a pointer to a preview image, or NULL if no image is
 *         available.
 *
 */
const aom_image_t *aom_codec_get_preview_frame(aom_codec_ctx_t *ctx);

/*!@} - end defgroup encoder*/
#ifdef __cplusplus
}
#endif
#endif  // AOM_AOM_ENCODER_H_