Move aom source to a sub-directory under media/libaom

There is no damned reason to treat this differently than any other media lib given its license and there never was.

1 files changed, 981 insertions, 0 deletions

diff --git a/media/libaom/src/aom/aom_encoder.h b/media/libaom/src/aom/aom_encoder.h
new file mode 100644
index 000000000..0894ca9e3
--- /dev/null
+++ b/media/libaom/src/aom/aom_encoder.h
@@ -0,0 +1,981 @@
+/*
+ * 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_AOM_ENCODER_H_
+#define AOM_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 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_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 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.
+ * Calls to this function should be deferred until all configuration information
+ * has been passed to libaom. Otherwise the global header data may be
+ * invalidated by additional configuration changes.
+ *
+ * The AV1 implementation of this function returns an OBU. The OBU returned is
+ * in Low Overhead Bitstream Format. Specifically, the obu_has_size_field bit is
+ * set, and the buffer contains the obu_size field for the returned OBU.
+ *
+ * \param[in]    ctx     Pointer to this instance's context
+ *
+ * \retval NULL
+ *     Encoder does not support global header, or an error occurred while
+ *     generating the global header.
+ *
+ * \retval Non-NULL
+ *     Pointer to buffer containing global header packet. The caller owns the
+ *     memory associated with this buffer, and must free the 'buf' member of the
+ *     aom_fixed_buf_t as well as the aom_fixed_buf_t pointer. Memory returned
+ *     must be freed via call to free().
+ */
+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_AOM_ENCODER_H_