2 * Copyright (c) 2010 The WebM project authors. All Rights Reserved.
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.
12 /*!\defgroup encoder Encoder Algorithm Interface
14 * This abstraction allows applications using this encoder to easily support
15 * multiple video formats with minimal code duplication. This section describes
16 * the interface common to all encoders.
21 * \brief Describes the encoder algorithm interface to applications.
23 * This file describes the interface between an application and a
24 * video encoder algorithm.
33 #include "vpx_codec.h"
35 /*! Temporal Scalability: Maximum length of the sequence defining frame
38 #define VPX_TS_MAX_PERIODICITY 16
40 /*! Temporal Scalability: Maximum number of coding layers */
41 #define VPX_TS_MAX_LAYERS 5
43 /*!\deprecated Use #VPX_TS_MAX_PERIODICITY instead. */
44 #define MAX_PERIODICITY VPX_TS_MAX_PERIODICITY
46 /*!\deprecated Use #VPX_TS_MAX_LAYERS instead. */
47 #define MAX_LAYERS VPX_TS_MAX_LAYERS
49 /*!\brief Current ABI version number
52 * If this file is altered in any way that changes the ABI, this value
53 * must be bumped. Examples include, but are not limited to, changing
54 * types, removing or reassigning enums, adding/removing/rearranging
55 * fields to structures
57 #define VPX_ENCODER_ABI_VERSION (3 + VPX_CODEC_ABI_VERSION) /**<\hideinitializer*/
60 /*! \brief Encoder capabilities bitfield
62 * Each encoder advertises the capabilities it supports as part of its
63 * ::vpx_codec_iface_t interface structure. Capabilities are extra
64 * interfaces or functionality, and are not required to be supported
67 * The available flags are specified by VPX_CODEC_CAP_* defines.
69 #define VPX_CODEC_CAP_PSNR 0x10000 /**< Can issue PSNR packets */
71 /*! Can output one partition at a time. Each partition is returned in its
72 * own VPX_CODEC_CX_FRAME_PKT, with the FRAME_IS_FRAGMENT flag set for
73 * every partition but the last. In this mode all frames are always
74 * returned partition by partition.
76 #define VPX_CODEC_CAP_OUTPUT_PARTITION 0x20000
79 /*! \brief Initialization-time Feature Enabling
81 * Certain codec features must be known at initialization time, to allow
82 * for proper memory allocation.
84 * The available flags are specified by VPX_CODEC_USE_* defines.
86 #define VPX_CODEC_USE_PSNR 0x10000 /**< Calculate PSNR on each frame */
87 #define VPX_CODEC_USE_OUTPUT_PARTITION 0x20000 /**< Make the encoder output one
88 partition at a time. */
91 /*!\brief Generic fixed size buffer structure
93 * This structure is able to hold a reference to any fixed size buffer.
95 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 */
102 /*!\brief Time Stamp Type
104 * An integer, which when multiplied by the stream's time base, provides
105 * the absolute time of a sample.
107 typedef int64_t vpx_codec_pts_t;
110 /*!\brief Compressed Frame Flags
112 * This type represents a bitfield containing information about a compressed
113 * frame that may be useful to an application. The most significant 16 bits
114 * can be used by an algorithm to provide additional detail, for example to
115 * support frame types that are codec specific (MPEG-1 D-frames for example)
117 typedef uint32_t vpx_codec_frame_flags_t;
118 #define VPX_FRAME_IS_KEY 0x1 /**< frame is the start of a GOP */
119 #define VPX_FRAME_IS_DROPPABLE 0x2 /**< frame can be dropped without affecting
120 the stream (no future frame depends on
122 #define VPX_FRAME_IS_INVISIBLE 0x4 /**< frame should be decoded but will not
124 #define VPX_FRAME_IS_FRAGMENT 0x8 /**< this is a fragment of the encoded
127 /*!\brief Error Resilient flags
129 * These flags define which error resilient features to enable in the
130 * encoder. The flags are specified through the
131 * vpx_codec_enc_cfg::g_error_resilient variable.
133 typedef uint32_t vpx_codec_er_flags_t;
134 #define VPX_ERROR_RESILIENT_DEFAULT 0x1 /**< Improve resiliency against
135 losses of whole frames */
136 #define VPX_ERROR_RESILIENT_PARTITIONS 0x2 /**< The frame partitions are
137 independently decodable by the
138 bool decoder, meaning that
139 partitions can be decoded even
140 though earlier partitions have
141 been lost. Note that intra
142 predicition is still done over
143 the partition boundary. */
145 /*!\brief Encoder output packet variants
147 * This enumeration lists the different kinds of data packets that can be
148 * returned by calls to vpx_codec_get_cx_data(). Algorithms \ref MAY
149 * extend this list to provide additional functionality.
151 enum vpx_codec_cx_pkt_kind
153 VPX_CODEC_CX_FRAME_PKT, /**< Compressed video frame */
154 VPX_CODEC_STATS_PKT, /**< Two-pass statistics for this frame */
155 VPX_CODEC_PSNR_PKT, /**< PSNR statistics for this frame */
156 VPX_CODEC_CUSTOM_PKT = 256 /**< Algorithm extensions */
160 /*!\brief Encoder output packet
162 * This structure contains the different kinds of output data the encoder
163 * may produce while compressing a frame.
165 typedef struct vpx_codec_cx_pkt
167 enum vpx_codec_cx_pkt_kind kind; /**< packet variant */
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
186 } frame; /**< data for compressed frame packet */
187 struct vpx_fixed_buf twopass_stats; /**< data for two-pass packet */
190 unsigned int samples[4]; /**< Number of samples, total/y/u/v */
191 uint64_t sse[4]; /**< sum squared error, total/y/u/v */
192 double psnr[4]; /**< PSNR, total/y/u/v */
193 } psnr; /**< data for PSNR packet */
194 struct vpx_fixed_buf raw; /**< data for arbitrary packets */
196 /* This packet size is fixed to allow codecs to extend this
197 * interface without having to manage storage for raw packets,
198 * i.e., if it's smaller than 128 bytes, you can store in the
199 * packet list directly.
201 char pad[128 - sizeof(enum vpx_codec_cx_pkt_kind)]; /**< fixed sz */
202 } data; /**< packet data */
203 } vpx_codec_cx_pkt_t; /**< alias for struct vpx_codec_cx_pkt */
206 /*!\brief Rational Number
208 * This structure holds a fractional value.
210 typedef struct vpx_rational
212 int num; /**< fraction numerator */
213 int den; /**< fraction denominator */
214 } vpx_rational_t; /**< alias for struct vpx_rational */
217 /*!\brief Multi-pass Encoding Pass */
220 VPX_RC_ONE_PASS, /**< Single pass mode */
221 VPX_RC_FIRST_PASS, /**< First pass of multi-pass mode */
222 VPX_RC_LAST_PASS /**< Final pass of multi-pass mode */
226 /*!\brief Rate control mode */
229 VPX_VBR, /**< Variable Bit Rate (VBR) mode */
230 VPX_CBR, /**< Constant Bit Rate (CBR) mode */
231 VPX_CQ /**< Constant Quality (CQ) mode */
235 /*!\brief Keyframe placement mode.
237 * This enumeration determines whether keyframes are placed automatically by
238 * the encoder or whether this behavior is disabled. Older releases of this
239 * SDK were implemented such that VPX_KF_FIXED meant keyframes were disabled.
240 * This name is confusing for this behavior, so the new symbols to be used
241 * are VPX_KF_AUTO and VPX_KF_DISABLED.
245 VPX_KF_FIXED, /**< deprecated, implies VPX_KF_DISABLED */
246 VPX_KF_AUTO, /**< Encoder determines optimal placement automatically */
247 VPX_KF_DISABLED = 0 /**< Encoder does not place keyframes. */
251 /*!\brief Encoded Frame Flags
253 * This type indicates a bitfield to be passed to vpx_codec_encode(), defining
254 * per-frame boolean values. By convention, bits common to all codecs will be
255 * named VPX_EFLAG_*, and bits specific to an algorithm will be named
256 * /algo/_eflag_*. The lower order 16 bits are reserved for common use.
258 typedef long vpx_enc_frame_flags_t;
259 #define VPX_EFLAG_FORCE_KF (1<<0) /**< Force this frame to be a keyframe */
262 /*!\brief Encoder configuration structure
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,
268 typedef struct vpx_codec_enc_cfg
271 * generic settings (g)
274 /*!\brief Algorithm specific "usage" value
276 * Algorithms may define multiple values for usage, which may convey the
277 * intent of how the application intends to use the stream. If this value
278 * is non-zero, consult the documentation for the codec to determine its
281 unsigned int g_usage;
284 /*!\brief Maximum number of threads to use
286 * For multi-threaded implementations, use no more than this number of
287 * threads. The codec may use fewer threads than allowed. The value
288 * 0 is equivalent to the value 1.
290 unsigned int g_threads;
293 /*!\brief Bitstream profile to use
295 * Some codecs support a notion of multiple bitstream profiles. Typically
296 * this maps to a set of features that are turned on or off. Often the
297 * profile to use is determined by the features of the intended decoder.
298 * Consult the documentation for the codec to determine the valid values
299 * for this parameter, or set to zero for a sane default.
301 unsigned int g_profile; /**< profile of bitstream to use */
305 /*!\brief Width of the frame
307 * This value identifies the presentation resolution of the frame,
308 * in pixels. Note that the frames passed as input to the encoder must
309 * have this resolution. Frames will be presented by the decoder in this
310 * resolution, independent of any spatial resampling the encoder may do.
315 /*!\brief Height of the frame
317 * This value identifies the presentation resolution of the frame,
318 * in pixels. Note that the frames passed as input to the encoder must
319 * have this resolution. Frames will be presented by the decoder in this
320 * resolution, independent of any spatial resampling the encoder may do.
325 /*!\brief Stream timebase units
327 * Indicates the smallest interval of time, in seconds, used by the stream.
328 * For fixed frame rate material, or variable frame rate material where
329 * frames are timed at a multiple of a given clock (ex: video capture),
330 * the \ref RECOMMENDED method is to set the timebase to the reciprocal
331 * of the frame rate (ex: 1001/30000 for 29.970 Hz NTSC). This allows the
332 * pts to correspond to the frame number, which can be handy. For
333 * re-encoding video from containers with absolute time timestamps, the
334 * \ref RECOMMENDED method is to set the timebase to that of the parent
335 * container or multimedia framework (ex: 1/1000 for ms, as in FLV).
337 struct vpx_rational g_timebase;
340 /*!\brief Enable error resilient modes.
342 * The error resilient bitfield indicates to the encoder which features
343 * it should enable to take measures for streaming over lossy or noisy
346 vpx_codec_er_flags_t g_error_resilient;
349 /*!\brief Multi-pass Encoding Mode
351 * This value should be set to the current phase for multi-pass encoding.
352 * For single pass, set to #VPX_RC_ONE_PASS.
354 enum vpx_enc_pass g_pass;
357 /*!\brief Allow lagged encoding
359 * If set, this value allows the encoder to consume a number of input
360 * frames before producing output frames. This allows the encoder to
361 * base decisions for the current frame on future frames. This does
362 * increase the latency of the encoding pipeline, so it is not appropriate
363 * in all situations (ex: realtime encoding).
365 * Note that this is a maximum value -- the encoder may produce frames
366 * sooner than the given limit. Set this value to 0 to disable this
369 unsigned int g_lag_in_frames;
373 * rate control settings (rc)
376 /*!\brief Temporal resampling configuration, if supported by the codec.
378 * Temporal resampling allows the codec to "drop" frames as a strategy to
379 * meet its target data rate. This can cause temporal discontinuities in
380 * the encoded video, which may appear as stuttering during playback. This
381 * trade-off is often acceptable, but for many applications is not. It can
382 * be disabled in these cases.
384 * Note that not all codecs support this feature. All vpx VPx codecs do.
385 * For other codecs, consult the documentation for that algorithm.
387 * This threshold is described as a percentage of the target data buffer.
388 * When the data buffer falls below this percentage of fullness, a
389 * dropped frame is indicated. Set the threshold to zero (0) to disable
392 unsigned int rc_dropframe_thresh;
395 /*!\brief Enable/disable spatial resampling, if supported by the codec.
397 * Spatial resampling allows the codec to compress a lower resolution
398 * version of the frame, which is then upscaled by the encoder to the
399 * correct presentation resolution. This increases visual quality at
400 * low data rates, at the expense of CPU time on the encoder/decoder.
402 unsigned int rc_resize_allowed;
405 /*!\brief Spatial resampling up watermark.
407 * This threshold is described as a percentage of the target data buffer.
408 * When the data buffer rises above this percentage of fullness, the
409 * encoder will step up to a higher resolution version of the frame.
411 unsigned int rc_resize_up_thresh;
414 /*!\brief Spatial resampling down watermark.
416 * This threshold is described as a percentage of the target data buffer.
417 * When the data buffer falls below this percentage of fullness, the
418 * encoder will step down to a lower resolution version of the frame.
420 unsigned int rc_resize_down_thresh;
423 /*!\brief Rate control algorithm to use.
425 * Indicates whether the end usage of this stream is to be streamed over
426 * a bandwidth constrained link, indicating that Constant Bit Rate (CBR)
427 * mode should be used, or whether it will be played back on a high
428 * bandwidth link, as from a local disk, where higher variations in
429 * bitrate are acceptable.
431 enum vpx_rc_mode rc_end_usage;
434 /*!\brief Two-pass stats buffer.
436 * A buffer containing all of the stats packets produced in the first
437 * pass, concatenated.
439 struct vpx_fixed_buf rc_twopass_stats_in;
442 /*!\brief Target data rate
444 * Target bandwidth to use for this stream, in kilobits per second.
446 unsigned int rc_target_bitrate;
454 /*!\brief Minimum (Best Quality) Quantizer
456 * The quantizer is the most direct control over the quality of the
457 * encoded image. The range of valid values for the quantizer is codec
458 * specific. Consult the documentation for the codec to determine the
459 * values to use. To determine the range programmatically, call
460 * vpx_codec_enc_config_default() with a usage value of 0.
462 unsigned int rc_min_quantizer;
465 /*!\brief Maximum (Worst Quality) Quantizer
467 * The quantizer is the most direct control over the quality of the
468 * encoded image. The range of valid values for the quantizer is codec
469 * specific. Consult the documentation for the codec to determine the
470 * values to use. To determine the range programmatically, call
471 * vpx_codec_enc_config_default() with a usage value of 0.
473 unsigned int rc_max_quantizer;
481 /*!\brief Rate control adaptation undershoot control
483 * This value, expressed as a percentage of the target bitrate,
484 * controls the maximum allowed adaptation speed of the codec.
485 * This factor controls the maximum amount of bits that can
486 * be subtracted from the target bitrate in order to compensate
487 * for prior overshoot.
489 * Valid values in the range 0-1000.
491 unsigned int rc_undershoot_pct;
494 /*!\brief Rate control adaptation overshoot control
496 * This value, expressed as a percentage of the target bitrate,
497 * controls the maximum allowed adaptation speed of the codec.
498 * This factor controls the maximum amount of bits that can
499 * be added to the target bitrate in order to compensate for
502 * Valid values in the range 0-1000.
504 unsigned int rc_overshoot_pct;
508 * decoder buffer model parameters
512 /*!\brief Decoder Buffer Size
514 * This value indicates the amount of data that may be buffered by the
515 * decoding application. Note that this value is expressed in units of
516 * time (milliseconds). For example, a value of 5000 indicates that the
517 * client will buffer (at least) 5000ms worth of encoded data. Use the
518 * target bitrate (#rc_target_bitrate) to convert to bits/bytes, if
521 unsigned int rc_buf_sz;
524 /*!\brief Decoder Buffer Initial Size
526 * This value indicates the amount of data that will be buffered by the
527 * decoding application prior to beginning playback. This value is
528 * expressed in units of time (milliseconds). Use the target bitrate
529 * (#rc_target_bitrate) to convert to bits/bytes, if necessary.
531 unsigned int rc_buf_initial_sz;
534 /*!\brief Decoder Buffer Optimal Size
536 * This value indicates the amount of data that the encoder should try
537 * to maintain in the decoder's buffer. This value is expressed in units
538 * of time (milliseconds). Use the target bitrate (#rc_target_bitrate)
539 * to convert to bits/bytes, if necessary.
541 unsigned int rc_buf_optimal_sz;
545 * 2 pass rate control parameters
549 /*!\brief Two-pass mode CBR/VBR bias
551 * Bias, expressed on a scale of 0 to 100, for determining target size
552 * for the current frame. The value 0 indicates the optimal CBR mode
553 * value should be used. The value 100 indicates the optimal VBR mode
554 * value should be used. Values in between indicate which way the
555 * encoder should "lean."
557 unsigned int rc_2pass_vbr_bias_pct; /**< RC mode bias between CBR and VBR(0-100: 0->CBR, 100->VBR) */
560 /*!\brief Two-pass mode per-GOP minimum bitrate
562 * This value, expressed as a percentage of the target bitrate, indicates
563 * the minimum bitrate to be used for a single GOP (aka "section")
565 unsigned int rc_2pass_vbr_minsection_pct;
568 /*!\brief Two-pass mode per-GOP maximum bitrate
570 * This value, expressed as a percentage of the target bitrate, indicates
571 * the maximum bitrate to be used for a single GOP (aka "section")
573 unsigned int rc_2pass_vbr_maxsection_pct;
577 * keyframing settings (kf)
580 /*!\brief Keyframe placement mode
582 * This value indicates whether the encoder should place keyframes at a
583 * fixed interval, or determine the optimal placement automatically
584 * (as governed by the #kf_min_dist and #kf_max_dist parameters)
586 enum vpx_kf_mode kf_mode;
589 /*!\brief Keyframe minimum interval
591 * This value, expressed as a number of frames, prevents the encoder from
592 * placing a keyframe nearer than kf_min_dist to the previous keyframe. At
593 * least kf_min_dist frames non-keyframes will be coded before the next
594 * keyframe. Set kf_min_dist equal to kf_max_dist for a fixed interval.
596 unsigned int kf_min_dist;
599 /*!\brief Keyframe maximum interval
601 * This value, expressed as a number of frames, forces the encoder to code
602 * a keyframe if one has not been coded in the last kf_max_dist frames.
603 * A value of 0 implies all frames will be keyframes. Set kf_min_dist
604 * equal to kf_max_dist for a fixed interval.
606 unsigned int kf_max_dist;
609 * Temporal scalability settings (ts)
612 /*!\brief Number of coding layers
614 * This value specifies the number of coding layers to be used.
616 unsigned int ts_number_layers;
618 /*!\brief Target bitrate for each layer
620 * These values specify the target coding bitrate for each coding layer.
622 unsigned int ts_target_bitrate[VPX_TS_MAX_LAYERS];
624 /*!\brief Frame rate decimation factor for each layer
626 * These values specify the frame rate decimation factors to apply
629 unsigned int ts_rate_decimator[VPX_TS_MAX_LAYERS];
631 /*!\brief Length of the sequence defining frame layer membership
633 * This value specifies the length of the sequence that defines the
634 * membership of frames to layers. For example, if ts_periodicity=8 then
635 * frames are assigned to coding layers with a repeated sequence of
638 unsigned int ts_periodicity;
640 /*!\brief Template defining the membership of frames to coding layers
642 * This array defines the membership of frames to coding layers. For a
643 * 2-layer encoding that assigns even numbered frames to one layer (0)
644 * and odd numbered frames to a second layer (1) with ts_periodicity=8,
645 * then ts_layer_id = (0,1,0,1,0,1,0,1).
647 unsigned int ts_layer_id[VPX_TS_MAX_PERIODICITY];
648 } vpx_codec_enc_cfg_t; /**< alias for struct vpx_codec_enc_cfg */
651 /*!\brief Initialize an encoder instance
653 * Initializes a encoder context using the given interface. Applications
654 * should call the vpx_codec_enc_init convenience macro instead of this
655 * function directly, to ensure that the ABI version number parameter
656 * is properly initialized.
658 * In XMA mode (activated by setting VPX_CODEC_USE_XMA in the flags
659 * parameter), the storage pointed to by the cfg parameter must be
660 * kept readable and stable until all memory maps have been set.
662 * \param[in] ctx Pointer to this instance's context.
663 * \param[in] iface Pointer to the algorithm interface to use.
664 * \param[in] cfg Configuration to use, if known. May be NULL.
665 * \param[in] flags Bitfield of VPX_CODEC_USE_* flags
666 * \param[in] ver ABI version number. Must be set to
667 * VPX_ENCODER_ABI_VERSION
668 * \retval #VPX_CODEC_OK
669 * The decoder algorithm initialized.
670 * \retval #VPX_CODEC_MEM_ERROR
671 * Memory allocation failed.
673 vpx_codec_err_t vpx_codec_enc_init_ver(vpx_codec_ctx_t *ctx,
674 vpx_codec_iface_t *iface,
675 vpx_codec_enc_cfg_t *cfg,
676 vpx_codec_flags_t flags,
680 /*!\brief Convenience macro for vpx_codec_enc_init_ver()
682 * Ensures the ABI version parameter is properly set.
684 #define vpx_codec_enc_init(ctx, iface, cfg, flags) \
685 vpx_codec_enc_init_ver(ctx, iface, cfg, flags, VPX_ENCODER_ABI_VERSION)
688 /*!\brief Initialize multi-encoder instance
690 * Initializes multi-encoder context using the given interface.
691 * Applications should call the vpx_codec_enc_init_multi convenience macro
692 * instead of this function directly, to ensure that the ABI version number
693 * parameter is properly initialized.
695 * In XMA mode (activated by setting VPX_CODEC_USE_XMA in the flags
696 * parameter), the storage pointed to by the cfg parameter must be
697 * kept readable and stable until all memory maps have been set.
699 * \param[in] ctx Pointer to this instance's context.
700 * \param[in] iface Pointer to the algorithm interface to use.
701 * \param[in] cfg Configuration to use, if known. May be NULL.
702 * \param[in] num_enc Total number of encoders.
703 * \param[in] flags Bitfield of VPX_CODEC_USE_* flags
704 * \param[in] dsf Pointer to down-sampling factors.
705 * \param[in] ver ABI version number. Must be set to
706 * VPX_ENCODER_ABI_VERSION
707 * \retval #VPX_CODEC_OK
708 * The decoder algorithm initialized.
709 * \retval #VPX_CODEC_MEM_ERROR
710 * Memory allocation failed.
712 vpx_codec_err_t vpx_codec_enc_init_multi_ver(vpx_codec_ctx_t *ctx,
713 vpx_codec_iface_t *iface,
714 vpx_codec_enc_cfg_t *cfg,
716 vpx_codec_flags_t flags,
721 /*!\brief Convenience macro for vpx_codec_enc_init_multi_ver()
723 * Ensures the ABI version parameter is properly set.
725 #define vpx_codec_enc_init_multi(ctx, iface, cfg, num_enc, flags, dsf) \
726 vpx_codec_enc_init_multi_ver(ctx, iface, cfg, num_enc, flags, dsf, \
727 VPX_ENCODER_ABI_VERSION)
730 /*!\brief Get a default configuration
732 * Initializes a encoder configuration structure with default values. Supports
733 * the notion of "usages" so that an algorithm may offer different default
734 * settings depending on the user's intended goal. This function \ref SHOULD
735 * be called by all applications to initialize the configuration structure
736 * before specializing the configuration with application specific values.
738 * \param[in] iface Pointer to the algorithm interface to use.
739 * \param[out] cfg Configuration buffer to populate
740 * \param[in] usage End usage. Set to 0 or use codec specific values.
742 * \retval #VPX_CODEC_OK
743 * The configuration was populated.
744 * \retval #VPX_CODEC_INCAPABLE
745 * Interface is not an encoder interface.
746 * \retval #VPX_CODEC_INVALID_PARAM
747 * A parameter was NULL, or the usage value was not recognized.
749 vpx_codec_err_t vpx_codec_enc_config_default(vpx_codec_iface_t *iface,
750 vpx_codec_enc_cfg_t *cfg,
754 /*!\brief Set or change configuration
756 * Reconfigures an encoder instance according to the given configuration.
758 * \param[in] ctx Pointer to this instance's context
759 * \param[in] cfg Configuration buffer to use
761 * \retval #VPX_CODEC_OK
762 * The configuration was populated.
763 * \retval #VPX_CODEC_INCAPABLE
764 * Interface is not an encoder interface.
765 * \retval #VPX_CODEC_INVALID_PARAM
766 * A parameter was NULL, or the usage value was not recognized.
768 vpx_codec_err_t vpx_codec_enc_config_set(vpx_codec_ctx_t *ctx,
769 const vpx_codec_enc_cfg_t *cfg);
772 /*!\brief Get global stream headers
774 * Retrieves a stream level global header packet, if supported by the codec.
776 * \param[in] ctx Pointer to this instance's context
779 * Encoder does not support global header
781 * Pointer to buffer containing global header packet
783 vpx_fixed_buf_t *vpx_codec_get_global_headers(vpx_codec_ctx_t *ctx);
786 #define VPX_DL_REALTIME (1) /**< deadline parameter analogous to
787 * VPx REALTIME mode. */
788 #define VPX_DL_GOOD_QUALITY (1000000) /**< deadline parameter analogous to
789 * VPx GOOD QUALITY mode. */
790 #define VPX_DL_BEST_QUALITY (0) /**< deadline parameter analogous to
791 * VPx BEST QUALITY mode. */
792 /*!\brief Encode a frame
794 * Encodes a video frame at the given "presentation time." The presentation
795 * time stamp (PTS) \ref MUST be strictly increasing.
797 * The encoder supports the notion of a soft real-time deadline. Given a
798 * non-zero value to the deadline parameter, the encoder will make a "best
799 * effort" guarantee to return before the given time slice expires. It is
800 * implicit that limiting the available time to encode will degrade the
801 * output quality. The encoder can be given an unlimited time to produce the
802 * best possible frame by specifying a deadline of '0'. This deadline
803 * supercedes the VPx notion of "best quality, good quality, realtime".
804 * Applications that wish to map these former settings to the new deadline
805 * based system can use the symbols #VPX_DL_REALTIME, #VPX_DL_GOOD_QUALITY,
806 * and #VPX_DL_BEST_QUALITY.
808 * When the last frame has been passed to the encoder, this function should
809 * continue to be called, with the img parameter set to NULL. This will
810 * signal the end-of-stream condition to the encoder and allow it to encode
811 * any held buffers. Encoding is complete when vpx_codec_encode() is called
812 * and vpx_codec_get_cx_data() returns no data.
814 * \param[in] ctx Pointer to this instance's context
815 * \param[in] img Image data to encode, NULL to flush.
816 * \param[in] pts Presentation time stamp, in timebase units.
817 * \param[in] duration Duration to show frame, in timebase units.
818 * \param[in] flags Flags to use for encoding this frame.
819 * \param[in] deadline Time to spend encoding, in microseconds. (0=infinite)
821 * \retval #VPX_CODEC_OK
822 * The configuration was populated.
823 * \retval #VPX_CODEC_INCAPABLE
824 * Interface is not an encoder interface.
825 * \retval #VPX_CODEC_INVALID_PARAM
826 * A parameter was NULL, the image format is unsupported, etc.
828 vpx_codec_err_t vpx_codec_encode(vpx_codec_ctx_t *ctx,
829 const vpx_image_t *img,
831 unsigned long duration,
832 vpx_enc_frame_flags_t flags,
833 unsigned long deadline);
835 /*!\brief Set compressed data output buffer
837 * Sets the buffer that the codec should output the compressed data
838 * into. This call effectively sets the buffer pointer returned in the
839 * next VPX_CODEC_CX_FRAME_PKT packet. Subsequent packets will be
840 * appended into this buffer. The buffer is preserved across frames,
841 * so applications must periodically call this function after flushing
842 * the accumulated compressed data to disk or to the network to reset
843 * the pointer to the buffer's head.
845 * `pad_before` bytes will be skipped before writing the compressed
846 * data, and `pad_after` bytes will be appended to the packet. The size
847 * of the packet will be the sum of the size of the actual compressed
848 * data, pad_before, and pad_after. The padding bytes will be preserved
851 * Note that calling this function does not guarantee that the returned
852 * compressed data will be placed into the specified buffer. In the
853 * event that the encoded data will not fit into the buffer provided,
854 * the returned packet \ref MAY point to an internal buffer, as it would
855 * if this call were never used. In this event, the output packet will
856 * NOT have any padding, and the application must free space and copy it
857 * to the proper place. This is of particular note in configurations
858 * that may output multiple packets for a single encoded frame (e.g., lagged
859 * encoding) or if the application does not reset the buffer periodically.
861 * Applications may restore the default behavior of the codec providing
862 * the compressed data buffer by calling this function with a NULL
865 * Applications \ref MUSTNOT call this function during iteration of
866 * vpx_codec_get_cx_data().
868 * \param[in] ctx Pointer to this instance's context
869 * \param[in] buf Buffer to store compressed data into
870 * \param[in] pad_before Bytes to skip before writing compressed data
871 * \param[in] pad_after Bytes to skip after writing compressed data
873 * \retval #VPX_CODEC_OK
874 * The buffer was set successfully.
875 * \retval #VPX_CODEC_INVALID_PARAM
876 * A parameter was NULL, the image format is unsupported, etc.
878 vpx_codec_err_t vpx_codec_set_cx_data_buf(vpx_codec_ctx_t *ctx,
879 const vpx_fixed_buf_t *buf,
880 unsigned int pad_before,
881 unsigned int pad_after);
884 /*!\brief Encoded data iterator
886 * Iterates over a list of data packets to be passed from the encoder to the
887 * application. The different kinds of packets available are enumerated in
888 * #vpx_codec_cx_pkt_kind.
890 * #VPX_CODEC_CX_FRAME_PKT packets should be passed to the application's
891 * muxer. Multiple compressed frames may be in the list.
892 * #VPX_CODEC_STATS_PKT packets should be appended to a global buffer.
894 * The application \ref MUST silently ignore any packet kinds that it does
895 * not recognize or support.
897 * The data buffers returned from this function are only guaranteed to be
898 * valid until the application makes another call to any vpx_codec_* function.
900 * \param[in] ctx Pointer to this instance's context
901 * \param[in,out] iter Iterator storage, initialized to NULL
903 * \return Returns a pointer to an output data packet (compressed frame data,
904 * two-pass statistics, etc.) or NULL to signal end-of-list.
907 const vpx_codec_cx_pkt_t *vpx_codec_get_cx_data(vpx_codec_ctx_t *ctx,
908 vpx_codec_iter_t *iter);
911 /*!\brief Get Preview Frame
913 * Returns an image that can be used as a preview. Shows the image as it would
914 * exist at the decompressor. The application \ref MUST NOT write into this
917 * \param[in] ctx Pointer to this instance's context
919 * \return Returns a pointer to a preview image, or NULL if no image is
923 const vpx_image_t *vpx_codec_get_preview_frame(vpx_codec_ctx_t *ctx);
926 /*!@} - end defgroup encoder*/