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      1 /*
      2  *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
      3  *
      4  *  Use of this source code is governed by a BSD-style license
      5  *  that can be found in the LICENSE file in the root of the source
      6  *  tree. An additional intellectual property rights grant can be found
      7  *  in the file PATENTS.  All contributing project authors may
      8  *  be found in the AUTHORS file in the root of the source tree.
      9  */
     10 #ifndef VPX_VPX_VPX_ENCODER_H_
     11 #define VPX_VPX_VPX_ENCODER_H_
     12 
     13 /*!\defgroup encoder Encoder Algorithm Interface
     14  * \ingroup codec
     15  * This abstraction allows applications using this encoder to easily support
     16  * multiple video formats with minimal code duplication. This section describes
     17  * the interface common to all encoders.
     18  * @{
     19  */
     20 
     21 /*!\file
     22  * \brief Describes the encoder algorithm interface to applications.
     23  *
     24  * This file describes the interface between an application and a
     25  * video encoder algorithm.
     26  *
     27  */
     28 #ifdef __cplusplus
     29 extern "C" {
     30 #endif
     31 
     32 #include "./vpx_codec.h"
     33 
     34 /*! Temporal Scalability: Maximum length of the sequence defining frame
     35  * layer membership
     36  */
     37 #define VPX_TS_MAX_PERIODICITY 16
     38 
     39 /*! Temporal Scalability: Maximum number of coding layers */
     40 #define VPX_TS_MAX_LAYERS 5
     41 
     42 /*! Temporal+Spatial Scalability: Maximum number of coding layers */
     43 #define VPX_MAX_LAYERS 12  // 3 temporal + 4 spatial layers are allowed.
     44 
     45 /*! Spatial Scalability: Maximum number of coding layers */
     46 #define VPX_SS_MAX_LAYERS 5
     47 
     48 /*! Spatial Scalability: Default number of coding layers */
     49 #define VPX_SS_DEFAULT_LAYERS 1
     50 
     51 /*!\brief Current ABI version number
     52  *
     53  * \internal
     54  * If this file is altered in any way that changes the ABI, this value
     55  * must be bumped.  Examples include, but are not limited to, changing
     56  * types, removing or reassigning enums, adding/removing/rearranging
     57  * fields to structures
     58  */
     59 #define VPX_ENCODER_ABI_VERSION \
     60   (14 + VPX_CODEC_ABI_VERSION) /**<\hideinitializer*/
     61 
     62 /*! \brief Encoder capabilities bitfield
     63  *
     64  *  Each encoder advertises the capabilities it supports as part of its
     65  *  ::vpx_codec_iface_t interface structure. Capabilities are extra
     66  *  interfaces or functionality, and are not required to be supported
     67  *  by an encoder.
     68  *
     69  *  The available flags are specified by VPX_CODEC_CAP_* defines.
     70  */
     71 #define VPX_CODEC_CAP_PSNR 0x10000 /**< Can issue PSNR packets */
     72 
     73 /*! Can output one partition at a time. Each partition is returned in its
     74  *  own VPX_CODEC_CX_FRAME_PKT, with the FRAME_IS_FRAGMENT flag set for
     75  *  every partition but the last. In this mode all frames are always
     76  *  returned partition by partition.
     77  */
     78 #define VPX_CODEC_CAP_OUTPUT_PARTITION 0x20000
     79 
     80 /*! \brief Initialization-time Feature Enabling
     81  *
     82  *  Certain codec features must be known at initialization time, to allow
     83  *  for proper memory allocation.
     84  *
     85  *  The available flags are specified by VPX_CODEC_USE_* defines.
     86  */
     87 #define VPX_CODEC_USE_PSNR 0x10000 /**< Calculate PSNR on each frame */
     88 /*!\brief Make the encoder output one  partition at a time. */
     89 #define VPX_CODEC_USE_OUTPUT_PARTITION 0x20000
     90 #define VPX_CODEC_USE_HIGHBITDEPTH 0x40000 /**< Use high bitdepth */
     91 
     92 /*!\brief Generic fixed size buffer structure
     93  *
     94  * This structure is able to hold a reference to any fixed size buffer.
     95  */
     96 typedef struct vpx_fixed_buf {
     97   void *buf;       /**< Pointer to the data */
     98   size_t sz;       /**< Length of the buffer, in chars */
     99 } vpx_fixed_buf_t; /**< alias for struct vpx_fixed_buf */
    100 
    101 /*!\brief Time Stamp Type
    102  *
    103  * An integer, which when multiplied by the stream's time base, provides
    104  * the absolute time of a sample.
    105  */
    106 typedef int64_t vpx_codec_pts_t;
    107 
    108 /*!\brief Compressed Frame Flags
    109  *
    110  * This type represents a bitfield containing information about a compressed
    111  * frame that may be useful to an application. The most significant 16 bits
    112  * can be used by an algorithm to provide additional detail, for example to
    113  * support frame types that are codec specific (MPEG-1 D-frames for example)
    114  */
    115 typedef uint32_t vpx_codec_frame_flags_t;
    116 #define VPX_FRAME_IS_KEY 0x1 /**< frame is the start of a GOP */
    117 /*!\brief frame can be dropped without affecting the stream (no future frame
    118  * depends on this one) */
    119 #define VPX_FRAME_IS_DROPPABLE 0x2
    120 /*!\brief frame should be decoded but will not be shown */
    121 #define VPX_FRAME_IS_INVISIBLE 0x4
    122 /*!\brief this is a fragment of the encoded frame */
    123 #define VPX_FRAME_IS_FRAGMENT 0x8
    124 
    125 /*!\brief Error Resilient flags
    126  *
    127  * These flags define which error resilient features to enable in the
    128  * encoder. The flags are specified through the
    129  * vpx_codec_enc_cfg::g_error_resilient variable.
    130  */
    131 typedef uint32_t vpx_codec_er_flags_t;
    132 /*!\brief Improve resiliency against losses of whole frames */
    133 #define VPX_ERROR_RESILIENT_DEFAULT 0x1
    134 /*!\brief The frame partitions are independently decodable by the bool decoder,
    135  * meaning that partitions can be decoded even though earlier partitions have
    136  * been lost. Note that intra prediction is still done over the partition
    137  * boundary. */
    138 #define VPX_ERROR_RESILIENT_PARTITIONS 0x2
    139 
    140 /*!\brief Encoder output packet variants
    141  *
    142  * This enumeration lists the different kinds of data packets that can be
    143  * returned by calls to vpx_codec_get_cx_data(). Algorithms \ref MAY
    144  * extend this list to provide additional functionality.
    145  */
    146 enum vpx_codec_cx_pkt_kind {
    147   VPX_CODEC_CX_FRAME_PKT,    /**< Compressed video frame */
    148   VPX_CODEC_STATS_PKT,       /**< Two-pass statistics for this frame */
    149   VPX_CODEC_FPMB_STATS_PKT,  /**< first pass mb statistics for this frame */
    150   VPX_CODEC_PSNR_PKT,        /**< PSNR statistics for this frame */
    151   VPX_CODEC_CUSTOM_PKT = 256 /**< Algorithm extensions  */
    152 };
    153 
    154 /*!\brief Encoder output packet
    155  *
    156  * This structure contains the different kinds of output data the encoder
    157  * may produce while compressing a frame.
    158  */
    159 typedef struct vpx_codec_cx_pkt {
    160   enum vpx_codec_cx_pkt_kind kind; /**< packet variant */
    161   union {
    162     struct {
    163       void *buf; /**< compressed data buffer */
    164       size_t sz; /**< length of compressed data */
    165       /*!\brief time stamp to show frame (in timebase units) */
    166       vpx_codec_pts_t pts;
    167       /*!\brief duration to show frame (in timebase units) */
    168       unsigned long duration;
    169       vpx_codec_frame_flags_t flags; /**< flags for this frame */
    170       /*!\brief the partition id defines the decoding order of the partitions.
    171        * Only applicable when "output partition" mode is enabled. First
    172        * partition has id 0.*/
    173       int partition_id;
    174       /*!\brief Width and height of frames in this packet. VP8 will only use the
    175        * first one.*/
    176       unsigned int width[VPX_SS_MAX_LAYERS];  /**< frame width */
    177       unsigned int height[VPX_SS_MAX_LAYERS]; /**< frame height */
    178       /*!\brief Flag to indicate if spatial layer frame in this packet is
    179        * encoded or dropped. VP8 will always be set to 1.*/
    180       uint8_t spatial_layer_encoded[VPX_SS_MAX_LAYERS];
    181     } frame;                            /**< data for compressed frame packet */
    182     vpx_fixed_buf_t twopass_stats;      /**< data for two-pass packet */
    183     vpx_fixed_buf_t firstpass_mb_stats; /**< first pass mb packet */
    184     struct vpx_psnr_pkt {
    185       unsigned int samples[4]; /**< Number of samples, total/y/u/v */
    186       uint64_t sse[4];         /**< sum squared error, total/y/u/v */
    187       double psnr[4];          /**< PSNR, total/y/u/v */
    188     } psnr;                    /**< data for PSNR packet */
    189     vpx_fixed_buf_t raw;       /**< data for arbitrary packets */
    190 
    191     /* This packet size is fixed to allow codecs to extend this
    192      * interface without having to manage storage for raw packets,
    193      * i.e., if it's smaller than 128 bytes, you can store in the
    194      * packet list directly.
    195      */
    196     char pad[128 - sizeof(enum vpx_codec_cx_pkt_kind)]; /**< fixed sz */
    197   } data;                                               /**< packet data */
    198 } vpx_codec_cx_pkt_t; /**< alias for struct vpx_codec_cx_pkt */
    199 
    200 /*!\brief Encoder return output buffer callback
    201  *
    202  * This callback function, when registered, returns with packets when each
    203  * spatial layer is encoded.
    204  */
    205 typedef void (*vpx_codec_enc_output_cx_pkt_cb_fn_t)(vpx_codec_cx_pkt_t *pkt,
    206                                                     void *user_data);
    207 
    208 /*!\brief Callback function pointer / user data pair storage */
    209 typedef struct vpx_codec_enc_output_cx_cb_pair {
    210   vpx_codec_enc_output_cx_pkt_cb_fn_t output_cx_pkt; /**< Callback function */
    211   void *user_priv; /**< Pointer to private data */
    212 } vpx_codec_priv_output_cx_pkt_cb_pair_t;
    213 
    214 /*!\brief Rational Number
    215  *
    216  * This structure holds a fractional value.
    217  */
    218 typedef struct vpx_rational {
    219   int num;        /**< fraction numerator */
    220   int den;        /**< fraction denominator */
    221 } vpx_rational_t; /**< alias for struct vpx_rational */
    222 
    223 /*!\brief Multi-pass Encoding Pass */
    224 enum vpx_enc_pass {
    225   VPX_RC_ONE_PASS,   /**< Single pass mode */
    226   VPX_RC_FIRST_PASS, /**< First pass of multi-pass mode */
    227   VPX_RC_LAST_PASS   /**< Final pass of multi-pass mode */
    228 };
    229 
    230 /*!\brief Rate control mode */
    231 enum vpx_rc_mode {
    232   VPX_VBR, /**< Variable Bit Rate (VBR) mode */
    233   VPX_CBR, /**< Constant Bit Rate (CBR) mode */
    234   VPX_CQ,  /**< Constrained Quality (CQ)  mode */
    235   VPX_Q,   /**< Constant Quality (Q) mode */
    236 };
    237 
    238 /*!\brief Keyframe placement mode.
    239  *
    240  * This enumeration determines whether keyframes are placed automatically by
    241  * the encoder or whether this behavior is disabled. Older releases of this
    242  * SDK were implemented such that VPX_KF_FIXED meant keyframes were disabled.
    243  * This name is confusing for this behavior, so the new symbols to be used
    244  * are VPX_KF_AUTO and VPX_KF_DISABLED.
    245  */
    246 enum vpx_kf_mode {
    247   VPX_KF_FIXED,       /**< deprecated, implies VPX_KF_DISABLED */
    248   VPX_KF_AUTO,        /**< Encoder determines optimal placement automatically */
    249   VPX_KF_DISABLED = 0 /**< Encoder does not place keyframes. */
    250 };
    251 
    252 /*!\brief Encoded Frame Flags
    253  *
    254  * This type indicates a bitfield to be passed to vpx_codec_encode(), defining
    255  * per-frame boolean values. By convention, bits common to all codecs will be
    256  * named VPX_EFLAG_*, and bits specific to an algorithm will be named
    257  * /algo/_eflag_*. The lower order 16 bits are reserved for common use.
    258  */
    259 typedef long vpx_enc_frame_flags_t;
    260 #define VPX_EFLAG_FORCE_KF (1 << 0) /**< Force this frame to be a keyframe */
    261 
    262 /*!\brief Encoder configuration structure
    263  *
    264  * This structure contains the encoder settings that have common representations
    265  * across all codecs. This doesn't imply that all codecs support all features,
    266  * however.
    267  */
    268 typedef struct vpx_codec_enc_cfg {
    269   /*
    270    * generic settings (g)
    271    */
    272 
    273   /*!\brief Deprecated: Algorithm specific "usage" value
    274    *
    275    * This value must be zero.
    276    */
    277   unsigned int g_usage;
    278 
    279   /*!\brief Maximum number of threads to use
    280    *
    281    * For multi-threaded implementations, use no more than this number of
    282    * threads. The codec may use fewer threads than allowed. The value
    283    * 0 is equivalent to the value 1.
    284    */
    285   unsigned int g_threads;
    286 
    287   /*!\brief Bitstream profile to use
    288    *
    289    * Some codecs support a notion of multiple bitstream profiles. Typically
    290    * this maps to a set of features that are turned on or off. Often the
    291    * profile to use is determined by the features of the intended decoder.
    292    * Consult the documentation for the codec to determine the valid values
    293    * for this parameter, or set to zero for a sane default.
    294    */
    295   unsigned int g_profile; /**< profile of bitstream to use */
    296 
    297   /*!\brief Width of the frame
    298    *
    299    * This value identifies the presentation resolution of the frame,
    300    * in pixels. Note that the frames passed as input to the encoder must
    301    * have this resolution. Frames will be presented by the decoder in this
    302    * resolution, independent of any spatial resampling the encoder may do.
    303    */
    304   unsigned int g_w;
    305 
    306   /*!\brief Height of the frame
    307    *
    308    * This value identifies the presentation resolution of the frame,
    309    * in pixels. Note that the frames passed as input to the encoder must
    310    * have this resolution. Frames will be presented by the decoder in this
    311    * resolution, independent of any spatial resampling the encoder may do.
    312    */
    313   unsigned int g_h;
    314 
    315   /*!\brief Bit-depth of the codec
    316    *
    317    * This value identifies the bit_depth of the codec,
    318    * Only certain bit-depths are supported as identified in the
    319    * vpx_bit_depth_t enum.
    320    */
    321   vpx_bit_depth_t g_bit_depth;
    322 
    323   /*!\brief Bit-depth of the input frames
    324    *
    325    * This value identifies the bit_depth of the input frames in bits.
    326    * Note that the frames passed as input to the encoder must have
    327    * this bit-depth.
    328    */
    329   unsigned int g_input_bit_depth;
    330 
    331   /*!\brief Stream timebase units
    332    *
    333    * Indicates the smallest interval of time, in seconds, used by the stream.
    334    * For fixed frame rate material, or variable frame rate material where
    335    * frames are timed at a multiple of a given clock (ex: video capture),
    336    * the \ref RECOMMENDED method is to set the timebase to the reciprocal
    337    * of the frame rate (ex: 1001/30000 for 29.970 Hz NTSC). This allows the
    338    * pts to correspond to the frame number, which can be handy. For
    339    * re-encoding video from containers with absolute time timestamps, the
    340    * \ref RECOMMENDED method is to set the timebase to that of the parent
    341    * container or multimedia framework (ex: 1/1000 for ms, as in FLV).
    342    */
    343   struct vpx_rational g_timebase;
    344 
    345   /*!\brief Enable error resilient modes.
    346    *
    347    * The error resilient bitfield indicates to the encoder which features
    348    * it should enable to take measures for streaming over lossy or noisy
    349    * links.
    350    */
    351   vpx_codec_er_flags_t g_error_resilient;
    352 
    353   /*!\brief Multi-pass Encoding Mode
    354    *
    355    * This value should be set to the current phase for multi-pass encoding.
    356    * For single pass, set to #VPX_RC_ONE_PASS.
    357    */
    358   enum vpx_enc_pass g_pass;
    359 
    360   /*!\brief Allow lagged encoding
    361    *
    362    * If set, this value allows the encoder to consume a number of input
    363    * frames before producing output frames. This allows the encoder to
    364    * base decisions for the current frame on future frames. This does
    365    * increase the latency of the encoding pipeline, so it is not appropriate
    366    * in all situations (ex: realtime encoding).
    367    *
    368    * Note that this is a maximum value -- the encoder may produce frames
    369    * sooner than the given limit. Set this value to 0 to disable this
    370    * feature.
    371    */
    372   unsigned int g_lag_in_frames;
    373 
    374   /*
    375    * rate control settings (rc)
    376    */
    377 
    378   /*!\brief Temporal resampling configuration, if supported by the codec.
    379    *
    380    * Temporal resampling allows the codec to "drop" frames as a strategy to
    381    * meet its target data rate. This can cause temporal discontinuities in
    382    * the encoded video, which may appear as stuttering during playback. This
    383    * trade-off is often acceptable, but for many applications is not. It can
    384    * be disabled in these cases.
    385    *
    386    * This threshold is described as a percentage of the target data buffer.
    387    * When the data buffer falls below this percentage of fullness, a
    388    * dropped frame is indicated. Set the threshold to zero (0) to disable
    389    * this feature.
    390    */
    391   unsigned int rc_dropframe_thresh;
    392 
    393   /*!\brief Enable/disable spatial resampling, if supported by the codec.
    394    *
    395    * Spatial resampling allows the codec to compress a lower resolution
    396    * version of the frame, which is then upscaled by the encoder to the
    397    * correct presentation resolution. This increases visual quality at
    398    * low data rates, at the expense of CPU time on the encoder/decoder.
    399    */
    400   unsigned int rc_resize_allowed;
    401 
    402   /*!\brief Internal coded frame width.
    403    *
    404    * If spatial resampling is enabled this specifies the width of the
    405    * encoded frame.
    406    */
    407   unsigned int rc_scaled_width;
    408 
    409   /*!\brief Internal coded frame height.
    410    *
    411    * If spatial resampling is enabled this specifies the height of the
    412    * encoded frame.
    413    */
    414   unsigned int rc_scaled_height;
    415 
    416   /*!\brief Spatial resampling up watermark.
    417    *
    418    * This threshold is described as a percentage of the target data buffer.
    419    * When the data buffer rises above this percentage of fullness, the
    420    * encoder will step up to a higher resolution version of the frame.
    421    */
    422   unsigned int rc_resize_up_thresh;
    423 
    424   /*!\brief Spatial resampling down watermark.
    425    *
    426    * This threshold is described as a percentage of the target data buffer.
    427    * When the data buffer falls below this percentage of fullness, the
    428    * encoder will step down to a lower resolution version of the frame.
    429    */
    430   unsigned int rc_resize_down_thresh;
    431 
    432   /*!\brief Rate control algorithm to use.
    433    *
    434    * Indicates whether the end usage of this stream is to be streamed over
    435    * a bandwidth constrained link, indicating that Constant Bit Rate (CBR)
    436    * mode should be used, or whether it will be played back on a high
    437    * bandwidth link, as from a local disk, where higher variations in
    438    * bitrate are acceptable.
    439    */
    440   enum vpx_rc_mode rc_end_usage;
    441 
    442   /*!\brief Two-pass stats buffer.
    443    *
    444    * A buffer containing all of the stats packets produced in the first
    445    * pass, concatenated.
    446    */
    447   vpx_fixed_buf_t rc_twopass_stats_in;
    448 
    449   /*!\brief first pass mb stats buffer.
    450    *
    451    * A buffer containing all of the first pass mb stats packets produced
    452    * in the first pass, concatenated.
    453    */
    454   vpx_fixed_buf_t rc_firstpass_mb_stats_in;
    455 
    456   /*!\brief Target data rate
    457    *
    458    * Target bandwidth to use for this stream, in kilobits per second.
    459    */
    460   unsigned int rc_target_bitrate;
    461 
    462   /*
    463    * quantizer settings
    464    */
    465 
    466   /*!\brief Minimum (Best Quality) Quantizer
    467    *
    468    * The quantizer is the most direct control over the quality of the
    469    * encoded image. The range of valid values for the quantizer is codec
    470    * specific. Consult the documentation for the codec to determine the
    471    * values to use.
    472    */
    473   unsigned int rc_min_quantizer;
    474 
    475   /*!\brief Maximum (Worst Quality) Quantizer
    476    *
    477    * The quantizer is the most direct control over the quality of the
    478    * encoded image. The range of valid values for the quantizer is codec
    479    * specific. Consult the documentation for the codec to determine the
    480    * values to use.
    481    */
    482   unsigned int rc_max_quantizer;
    483 
    484   /*
    485    * bitrate tolerance
    486    */
    487 
    488   /*!\brief Rate control adaptation undershoot control
    489    *
    490    * VP8: Expressed as a percentage of the target bitrate,
    491    * controls the maximum allowed adaptation speed of the codec.
    492    * This factor controls the maximum amount of bits that can
    493    * be subtracted from the target bitrate in order to compensate
    494    * for prior overshoot.
    495    * VP9: Expressed as a percentage of the target bitrate, a threshold
    496    * undershoot level (current rate vs target) beyond which more aggressive
    497    * corrective measures are taken.
    498    *   *
    499    * Valid values in the range VP8:0-1000 VP9: 0-100.
    500    */
    501   unsigned int rc_undershoot_pct;
    502 
    503   /*!\brief Rate control adaptation overshoot control
    504    *
    505    * VP8: Expressed as a percentage of the target bitrate,
    506    * controls the maximum allowed adaptation speed of the codec.
    507    * This factor controls the maximum amount of bits that can
    508    * be added to the target bitrate in order to compensate for
    509    * prior undershoot.
    510    * VP9: Expressed as a percentage of the target bitrate, a threshold
    511    * overshoot level (current rate vs target) beyond which more aggressive
    512    * corrective measures are taken.
    513    *
    514    * Valid values in the range VP8:0-1000 VP9: 0-100.
    515    */
    516   unsigned int rc_overshoot_pct;
    517 
    518   /*
    519    * decoder buffer model parameters
    520    */
    521 
    522   /*!\brief Decoder Buffer Size
    523    *
    524    * This value indicates the amount of data that may be buffered by the
    525    * decoding application. Note that this value is expressed in units of
    526    * time (milliseconds). For example, a value of 5000 indicates that the
    527    * client will buffer (at least) 5000ms worth of encoded data. Use the
    528    * target bitrate (#rc_target_bitrate) to convert to bits/bytes, if
    529    * necessary.
    530    */
    531   unsigned int rc_buf_sz;
    532 
    533   /*!\brief Decoder Buffer Initial Size
    534    *
    535    * This value indicates the amount of data that will be buffered by the
    536    * decoding application prior to beginning playback. This value is
    537    * expressed in units of time (milliseconds). Use the target bitrate
    538    * (#rc_target_bitrate) to convert to bits/bytes, if necessary.
    539    */
    540   unsigned int rc_buf_initial_sz;
    541 
    542   /*!\brief Decoder Buffer Optimal Size
    543    *
    544    * This value indicates the amount of data that the encoder should try
    545    * to maintain in the decoder's buffer. This value is expressed in units
    546    * of time (milliseconds). Use the target bitrate (#rc_target_bitrate)
    547    * to convert to bits/bytes, if necessary.
    548    */
    549   unsigned int rc_buf_optimal_sz;
    550 
    551   /*
    552    * 2 pass rate control parameters
    553    */
    554 
    555   /*!\brief Two-pass mode CBR/VBR bias
    556    *
    557    * Bias, expressed on a scale of 0 to 100, for determining target size
    558    * for the current frame. The value 0 indicates the optimal CBR mode
    559    * value should be used. The value 100 indicates the optimal VBR mode
    560    * value should be used. Values in between indicate which way the
    561    * encoder should "lean."
    562    */
    563   unsigned int rc_2pass_vbr_bias_pct;
    564 
    565   /*!\brief Two-pass mode per-GOP minimum bitrate
    566    *
    567    * This value, expressed as a percentage of the target bitrate, indicates
    568    * the minimum bitrate to be used for a single GOP (aka "section")
    569    */
    570   unsigned int rc_2pass_vbr_minsection_pct;
    571 
    572   /*!\brief Two-pass mode per-GOP maximum bitrate
    573    *
    574    * This value, expressed as a percentage of the target bitrate, indicates
    575    * the maximum bitrate to be used for a single GOP (aka "section")
    576    */
    577   unsigned int rc_2pass_vbr_maxsection_pct;
    578 
    579   /*!\brief Two-pass corpus vbr mode complexity control
    580    * Used only in VP9: A value representing the corpus midpoint complexity
    581    * for corpus vbr mode. This value defaults to 0 which disables corpus vbr
    582    * mode in favour of normal vbr mode.
    583    */
    584   unsigned int rc_2pass_vbr_corpus_complexity;
    585 
    586   /*
    587    * keyframing settings (kf)
    588    */
    589 
    590   /*!\brief Keyframe placement mode
    591    *
    592    * This value indicates whether the encoder should place keyframes at a
    593    * fixed interval, or determine the optimal placement automatically
    594    * (as governed by the #kf_min_dist and #kf_max_dist parameters)
    595    */
    596   enum vpx_kf_mode kf_mode;
    597 
    598   /*!\brief Keyframe minimum interval
    599    *
    600    * This value, expressed as a number of frames, prevents the encoder from
    601    * placing a keyframe nearer than kf_min_dist to the previous keyframe. At
    602    * least kf_min_dist frames non-keyframes will be coded before the next
    603    * keyframe. Set kf_min_dist equal to kf_max_dist for a fixed interval.
    604    */
    605   unsigned int kf_min_dist;
    606 
    607   /*!\brief Keyframe maximum interval
    608    *
    609    * This value, expressed as a number of frames, forces the encoder to code
    610    * a keyframe if one has not been coded in the last kf_max_dist frames.
    611    * A value of 0 implies all frames will be keyframes. Set kf_min_dist
    612    * equal to kf_max_dist for a fixed interval.
    613    */
    614   unsigned int kf_max_dist;
    615 
    616   /*
    617    * Spatial scalability settings (ss)
    618    */
    619 
    620   /*!\brief Number of spatial coding layers.
    621    *
    622    * This value specifies the number of spatial coding layers to be used.
    623    */
    624   unsigned int ss_number_layers;
    625 
    626   /*!\brief Enable auto alt reference flags for each spatial layer.
    627    *
    628    * These values specify if auto alt reference frame is enabled for each
    629    * spatial layer.
    630    */
    631   int ss_enable_auto_alt_ref[VPX_SS_MAX_LAYERS];
    632 
    633   /*!\brief Target bitrate for each spatial layer.
    634    *
    635    * These values specify the target coding bitrate to be used for each
    636    * spatial layer.
    637    */
    638   unsigned int ss_target_bitrate[VPX_SS_MAX_LAYERS];
    639 
    640   /*!\brief Number of temporal coding layers.
    641    *
    642    * This value specifies the number of temporal layers to be used.
    643    */
    644   unsigned int ts_number_layers;
    645 
    646   /*!\brief Target bitrate for each temporal layer.
    647    *
    648    * These values specify the target coding bitrate to be used for each
    649    * temporal layer.
    650    */
    651   unsigned int ts_target_bitrate[VPX_TS_MAX_LAYERS];
    652 
    653   /*!\brief Frame rate decimation factor for each temporal layer.
    654    *
    655    * These values specify the frame rate decimation factors to apply
    656    * to each temporal layer.
    657    */
    658   unsigned int ts_rate_decimator[VPX_TS_MAX_LAYERS];
    659 
    660   /*!\brief Length of the sequence defining frame temporal layer membership.
    661    *
    662    * This value specifies the length of the sequence that defines the
    663    * membership of frames to temporal layers. For example, if the
    664    * ts_periodicity = 8, then the frames are assigned to coding layers with a
    665    * repeated sequence of length 8.
    666    */
    667   unsigned int ts_periodicity;
    668 
    669   /*!\brief Template defining the membership of frames to temporal layers.
    670    *
    671    * This array defines the membership of frames to temporal coding layers.
    672    * For a 2-layer encoding that assigns even numbered frames to one temporal
    673    * layer (0) and odd numbered frames to a second temporal layer (1) with
    674    * ts_periodicity=8, then ts_layer_id = (0,1,0,1,0,1,0,1).
    675    */
    676   unsigned int ts_layer_id[VPX_TS_MAX_PERIODICITY];
    677 
    678   /*!\brief Target bitrate for each spatial/temporal layer.
    679    *
    680    * These values specify the target coding bitrate to be used for each
    681    * spatial/temporal layer.
    682    *
    683    */
    684   unsigned int layer_target_bitrate[VPX_MAX_LAYERS];
    685 
    686   /*!\brief Temporal layering mode indicating which temporal layering scheme to
    687    * use.
    688    *
    689    * The value (refer to VP9E_TEMPORAL_LAYERING_MODE) specifies the
    690    * temporal layering mode to use.
    691    *
    692    */
    693   int temporal_layering_mode;
    694 } vpx_codec_enc_cfg_t; /**< alias for struct vpx_codec_enc_cfg */
    695 
    696 /*!\brief  vp9 svc extra configure parameters
    697  *
    698  * This defines max/min quantizers and scale factors for each layer
    699  *
    700  */
    701 typedef struct vpx_svc_parameters {
    702   int max_quantizers[VPX_MAX_LAYERS];     /**< Max Q for each layer */
    703   int min_quantizers[VPX_MAX_LAYERS];     /**< Min Q for each layer */
    704   int scaling_factor_num[VPX_MAX_LAYERS]; /**< Scaling factor-numerator */
    705   int scaling_factor_den[VPX_MAX_LAYERS]; /**< Scaling factor-denominator */
    706   int speed_per_layer[VPX_MAX_LAYERS];    /**< Speed setting for each sl */
    707   int temporal_layering_mode;             /**< Temporal layering mode */
    708 } vpx_svc_extra_cfg_t;
    709 
    710 /*!\brief Initialize an encoder instance
    711  *
    712  * Initializes a encoder context using the given interface. Applications
    713  * should call the vpx_codec_enc_init convenience macro instead of this
    714  * function directly, to ensure that the ABI version number parameter
    715  * is properly initialized.
    716  *
    717  * If the library was configured with --disable-multithread, this call
    718  * is not thread safe and should be guarded with a lock if being used
    719  * in a multithreaded context.
    720  *
    721  * \param[in]    ctx     Pointer to this instance's context.
    722  * \param[in]    iface   Pointer to the algorithm interface to use.
    723  * \param[in]    cfg     Configuration to use, if known. May be NULL.
    724  * \param[in]    flags   Bitfield of VPX_CODEC_USE_* flags
    725  * \param[in]    ver     ABI version number. Must be set to
    726  *                       VPX_ENCODER_ABI_VERSION
    727  * \retval #VPX_CODEC_OK
    728  *     The decoder algorithm initialized.
    729  * \retval #VPX_CODEC_MEM_ERROR
    730  *     Memory allocation failed.
    731  */
    732 vpx_codec_err_t vpx_codec_enc_init_ver(vpx_codec_ctx_t *ctx,
    733                                        vpx_codec_iface_t *iface,
    734                                        const vpx_codec_enc_cfg_t *cfg,
    735                                        vpx_codec_flags_t flags, int ver);
    736 
    737 /*!\brief Convenience macro for vpx_codec_enc_init_ver()
    738  *
    739  * Ensures the ABI version parameter is properly set.
    740  */
    741 #define vpx_codec_enc_init(ctx, iface, cfg, flags) \
    742   vpx_codec_enc_init_ver(ctx, iface, cfg, flags, VPX_ENCODER_ABI_VERSION)
    743 
    744 /*!\brief Initialize multi-encoder instance
    745  *
    746  * Initializes multi-encoder context using the given interface.
    747  * Applications should call the vpx_codec_enc_init_multi convenience macro
    748  * instead of this function directly, to ensure that the ABI version number
    749  * parameter is properly initialized.
    750  *
    751  * \param[in]    ctx     Pointer to this instance's context.
    752  * \param[in]    iface   Pointer to the algorithm interface to use.
    753  * \param[in]    cfg     Configuration to use, if known. May be NULL.
    754  * \param[in]    num_enc Total number of encoders.
    755  * \param[in]    flags   Bitfield of VPX_CODEC_USE_* flags
    756  * \param[in]    dsf     Pointer to down-sampling factors.
    757  * \param[in]    ver     ABI version number. Must be set to
    758  *                       VPX_ENCODER_ABI_VERSION
    759  * \retval #VPX_CODEC_OK
    760  *     The decoder algorithm initialized.
    761  * \retval #VPX_CODEC_MEM_ERROR
    762  *     Memory allocation failed.
    763  */
    764 vpx_codec_err_t vpx_codec_enc_init_multi_ver(
    765     vpx_codec_ctx_t *ctx, vpx_codec_iface_t *iface, vpx_codec_enc_cfg_t *cfg,
    766     int num_enc, vpx_codec_flags_t flags, vpx_rational_t *dsf, int ver);
    767 
    768 /*!\brief Convenience macro for vpx_codec_enc_init_multi_ver()
    769  *
    770  * Ensures the ABI version parameter is properly set.
    771  */
    772 #define vpx_codec_enc_init_multi(ctx, iface, cfg, num_enc, flags, dsf) \
    773   vpx_codec_enc_init_multi_ver(ctx, iface, cfg, num_enc, flags, dsf,   \
    774                                VPX_ENCODER_ABI_VERSION)
    775 
    776 /*!\brief Get a default configuration
    777  *
    778  * Initializes a encoder configuration structure with default values. Supports
    779  * the notion of "usages" so that an algorithm may offer different default
    780  * settings depending on the user's intended goal. This function \ref SHOULD
    781  * be called by all applications to initialize the configuration structure
    782  * before specializing the configuration with application specific values.
    783  *
    784  * \param[in]    iface     Pointer to the algorithm interface to use.
    785  * \param[out]   cfg       Configuration buffer to populate.
    786  * \param[in]    usage     Must be set to 0.
    787  *
    788  * \retval #VPX_CODEC_OK
    789  *     The configuration was populated.
    790  * \retval #VPX_CODEC_INCAPABLE
    791  *     Interface is not an encoder interface.
    792  * \retval #VPX_CODEC_INVALID_PARAM
    793  *     A parameter was NULL, or the usage value was not recognized.
    794  */
    795 vpx_codec_err_t vpx_codec_enc_config_default(vpx_codec_iface_t *iface,
    796                                              vpx_codec_enc_cfg_t *cfg,
    797                                              unsigned int usage);
    798 
    799 /*!\brief Set or change configuration
    800  *
    801  * Reconfigures an encoder instance according to the given configuration.
    802  *
    803  * \param[in]    ctx     Pointer to this instance's context
    804  * \param[in]    cfg     Configuration buffer to use
    805  *
    806  * \retval #VPX_CODEC_OK
    807  *     The configuration was populated.
    808  * \retval #VPX_CODEC_INCAPABLE
    809  *     Interface is not an encoder interface.
    810  * \retval #VPX_CODEC_INVALID_PARAM
    811  *     A parameter was NULL, or the usage value was not recognized.
    812  */
    813 vpx_codec_err_t vpx_codec_enc_config_set(vpx_codec_ctx_t *ctx,
    814                                          const vpx_codec_enc_cfg_t *cfg);
    815 
    816 /*!\brief Get global stream headers
    817  *
    818  * Retrieves a stream level global header packet, if supported by the codec.
    819  *
    820  * \param[in]    ctx     Pointer to this instance's context
    821  *
    822  * \retval NULL
    823  *     Encoder does not support global header
    824  * \retval Non-NULL
    825  *     Pointer to buffer containing global header packet
    826  */
    827 vpx_fixed_buf_t *vpx_codec_get_global_headers(vpx_codec_ctx_t *ctx);
    828 
    829 /*!\brief deadline parameter analogous to VPx REALTIME mode. */
    830 #define VPX_DL_REALTIME (1)
    831 /*!\brief deadline parameter analogous to  VPx GOOD QUALITY mode. */
    832 #define VPX_DL_GOOD_QUALITY (1000000)
    833 /*!\brief deadline parameter analogous to VPx BEST QUALITY mode. */
    834 #define VPX_DL_BEST_QUALITY (0)
    835 /*!\brief Encode a frame
    836  *
    837  * Encodes a video frame at the given "presentation time." The presentation
    838  * time stamp (PTS) \ref MUST be strictly increasing.
    839  *
    840  * The encoder supports the notion of a soft real-time deadline. Given a
    841  * non-zero value to the deadline parameter, the encoder will make a "best
    842  * effort" guarantee to  return before the given time slice expires. It is
    843  * implicit that limiting the available time to encode will degrade the
    844  * output quality. The encoder can be given an unlimited time to produce the
    845  * best possible frame by specifying a deadline of '0'. This deadline
    846  * supersedes the VPx notion of "best quality, good quality, realtime".
    847  * Applications that wish to map these former settings to the new deadline
    848  * based system can use the symbols #VPX_DL_REALTIME, #VPX_DL_GOOD_QUALITY,
    849  * and #VPX_DL_BEST_QUALITY.
    850  *
    851  * When the last frame has been passed to the encoder, this function should
    852  * continue to be called, with the img parameter set to NULL. This will
    853  * signal the end-of-stream condition to the encoder and allow it to encode
    854  * any held buffers. Encoding is complete when vpx_codec_encode() is called
    855  * and vpx_codec_get_cx_data() returns no data.
    856  *
    857  * \param[in]    ctx       Pointer to this instance's context
    858  * \param[in]    img       Image data to encode, NULL to flush.
    859  * \param[in]    pts       Presentation time stamp, in timebase units.
    860  * \param[in]    duration  Duration to show frame, in timebase units.
    861  * \param[in]    flags     Flags to use for encoding this frame.
    862  * \param[in]    deadline  Time to spend encoding, in microseconds. (0=infinite)
    863  *
    864  * \retval #VPX_CODEC_OK
    865  *     The configuration was populated.
    866  * \retval #VPX_CODEC_INCAPABLE
    867  *     Interface is not an encoder interface.
    868  * \retval #VPX_CODEC_INVALID_PARAM
    869  *     A parameter was NULL, the image format is unsupported, etc.
    870  */
    871 vpx_codec_err_t vpx_codec_encode(vpx_codec_ctx_t *ctx, const vpx_image_t *img,
    872                                  vpx_codec_pts_t pts, unsigned long duration,
    873                                  vpx_enc_frame_flags_t flags,
    874                                  unsigned long deadline);
    875 
    876 /*!\brief Set compressed data output buffer
    877  *
    878  * Sets the buffer that the codec should output the compressed data
    879  * into. This call effectively sets the buffer pointer returned in the
    880  * next VPX_CODEC_CX_FRAME_PKT packet. Subsequent packets will be
    881  * appended into this buffer. The buffer is preserved across frames,
    882  * so applications must periodically call this function after flushing
    883  * the accumulated compressed data to disk or to the network to reset
    884  * the pointer to the buffer's head.
    885  *
    886  * `pad_before` bytes will be skipped before writing the compressed
    887  * data, and `pad_after` bytes will be appended to the packet. The size
    888  * of the packet will be the sum of the size of the actual compressed
    889  * data, pad_before, and pad_after. The padding bytes will be preserved
    890  * (not overwritten).
    891  *
    892  * Note that calling this function does not guarantee that the returned
    893  * compressed data will be placed into the specified buffer. In the
    894  * event that the encoded data will not fit into the buffer provided,
    895  * the returned packet \ref MAY point to an internal buffer, as it would
    896  * if this call were never used. In this event, the output packet will
    897  * NOT have any padding, and the application must free space and copy it
    898  * to the proper place. This is of particular note in configurations
    899  * that may output multiple packets for a single encoded frame (e.g., lagged
    900  * encoding) or if the application does not reset the buffer periodically.
    901  *
    902  * Applications may restore the default behavior of the codec providing
    903  * the compressed data buffer by calling this function with a NULL
    904  * buffer.
    905  *
    906  * Applications \ref MUSTNOT call this function during iteration of
    907  * vpx_codec_get_cx_data().
    908  *
    909  * \param[in]    ctx         Pointer to this instance's context
    910  * \param[in]    buf         Buffer to store compressed data into
    911  * \param[in]    pad_before  Bytes to skip before writing compressed data
    912  * \param[in]    pad_after   Bytes to skip after writing compressed data
    913  *
    914  * \retval #VPX_CODEC_OK
    915  *     The buffer was set successfully.
    916  * \retval #VPX_CODEC_INVALID_PARAM
    917  *     A parameter was NULL, the image format is unsupported, etc.
    918  */
    919 vpx_codec_err_t vpx_codec_set_cx_data_buf(vpx_codec_ctx_t *ctx,
    920                                           const vpx_fixed_buf_t *buf,
    921                                           unsigned int pad_before,
    922                                           unsigned int pad_after);
    923 
    924 /*!\brief Encoded data iterator
    925  *
    926  * Iterates over a list of data packets to be passed from the encoder to the
    927  * application. The different kinds of packets available are enumerated in
    928  * #vpx_codec_cx_pkt_kind.
    929  *
    930  * #VPX_CODEC_CX_FRAME_PKT packets should be passed to the application's
    931  * muxer. Multiple compressed frames may be in the list.
    932  * #VPX_CODEC_STATS_PKT packets should be appended to a global buffer.
    933  *
    934  * The application \ref MUST silently ignore any packet kinds that it does
    935  * not recognize or support.
    936  *
    937  * The data buffers returned from this function are only guaranteed to be
    938  * valid until the application makes another call to any vpx_codec_* function.
    939  *
    940  * \param[in]     ctx      Pointer to this instance's context
    941  * \param[in,out] iter     Iterator storage, initialized to NULL
    942  *
    943  * \return Returns a pointer to an output data packet (compressed frame data,
    944  *         two-pass statistics, etc.) or NULL to signal end-of-list.
    945  *
    946  */
    947 const vpx_codec_cx_pkt_t *vpx_codec_get_cx_data(vpx_codec_ctx_t *ctx,
    948                                                 vpx_codec_iter_t *iter);
    949 
    950 /*!\brief Get Preview Frame
    951  *
    952  * Returns an image that can be used as a preview. Shows the image as it would
    953  * exist at the decompressor. The application \ref MUST NOT write into this
    954  * image buffer.
    955  *
    956  * \param[in]     ctx      Pointer to this instance's context
    957  *
    958  * \return Returns a pointer to a preview image, or NULL if no image is
    959  *         available.
    960  *
    961  */
    962 const vpx_image_t *vpx_codec_get_preview_frame(vpx_codec_ctx_t *ctx);
    963 
    964 /*!@} - end defgroup encoder*/
    965 #ifdef __cplusplus
    966 }
    967 #endif
    968 #endif  // VPX_VPX_VPX_ENCODER_H_
    969