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