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 #define MAX_PERIODICITY 16
38 /*!\brief Current ABI version number
41 * If this file is altered in any way that changes the ABI, this value
42 * must be bumped. Examples include, but are not limited to, changing
43 * types, removing or reassigning enums, adding/removing/rearranging
44 * fields to structures
46 #define VPX_ENCODER_ABI_VERSION (3 + VPX_CODEC_ABI_VERSION) /**<\hideinitializer*/
49 /*! \brief Encoder capabilities bitfield
51 * Each encoder advertises the capabilities it supports as part of its
52 * ::vpx_codec_iface_t interface structure. Capabilities are extra
53 * interfaces or functionality, and are not required to be supported
56 * The available flags are specified by VPX_CODEC_CAP_* defines.
58 #define VPX_CODEC_CAP_PSNR 0x10000 /**< Can issue PSNR packets */
60 /*! Can output one partition at a time. Each partition is returned in its
61 * own VPX_CODEC_CX_FRAME_PKT, with the FRAME_IS_FRAGMENT flag set for
62 * every partition but the last. In this mode all frames are always
63 * returned partition by partition.
65 #define VPX_CODEC_CAP_OUTPUT_PARTITION 0x20000
68 /*! \brief Initialization-time Feature Enabling
70 * Certain codec features must be known at initialization time, to allow
71 * for proper memory allocation.
73 * The available flags are specified by VPX_CODEC_USE_* defines.
75 #define VPX_CODEC_USE_PSNR 0x10000 /**< Calculate PSNR on each frame */
76 #define VPX_CODEC_USE_OUTPUT_PARTITION 0x20000 /**< Make the encoder output one
77 partition at a time. */
80 /*!\brief Generic fixed size buffer structure
82 * This structure is able to hold a reference to any fixed size buffer.
84 typedef struct vpx_fixed_buf
86 void *buf; /**< Pointer to the data */
87 size_t sz; /**< Length of the buffer, in chars */
88 } vpx_fixed_buf_t; /**< alias for struct vpx_fixed_buf */
91 /*!\brief Time Stamp Type
93 * An integer, which when multiplied by the stream's time base, provides
94 * the absolute time of a sample.
96 typedef int64_t vpx_codec_pts_t;
99 /*!\brief Compressed Frame Flags
101 * This type represents a bitfield containing information about a compressed
102 * frame that may be useful to an application. The most significant 16 bits
103 * can be used by an algorithm to provide additional detail, for example to
104 * support frame types that are codec specific (MPEG-1 D-frames for example)
106 typedef uint32_t vpx_codec_frame_flags_t;
107 #define VPX_FRAME_IS_KEY 0x1 /**< frame is the start of a GOP */
108 #define VPX_FRAME_IS_DROPPABLE 0x2 /**< frame can be dropped without affecting
109 the stream (no future frame depends on
111 #define VPX_FRAME_IS_INVISIBLE 0x4 /**< frame should be decoded but will not
113 #define VPX_FRAME_IS_FRAGMENT 0x8 /**< this is a fragment of the encoded
116 /*!\brief Error Resilient flags
118 * These flags define which error resilient features to enable in the
119 * encoder. The flags are specified through the
120 * vpx_codec_enc_cfg::g_error_resilient variable.
122 typedef uint32_t vpx_codec_er_flags_t;
123 #define VPX_ERROR_RESILIENT_DEFAULT 0x1 /**< Improve resiliency against
124 losses of whole frames */
125 #define VPX_ERROR_RESILIENT_PARTITIONS 0x2 /**< The frame partitions are
126 independently decodable by the
127 bool decoder, meaning that
128 partitions can be decoded even
129 though earlier partitions have
130 been lost. Note that intra
131 predicition is still done over
132 the partition boundary. */
134 /*!\brief Encoder output packet variants
136 * This enumeration lists the different kinds of data packets that can be
137 * returned by calls to vpx_codec_get_cx_data(). Algorithms \ref MAY
138 * extend this list to provide additional functionality.
140 enum vpx_codec_cx_pkt_kind
142 VPX_CODEC_CX_FRAME_PKT, /**< Compressed video frame */
143 VPX_CODEC_STATS_PKT, /**< Two-pass statistics for this frame */
144 VPX_CODEC_PSNR_PKT, /**< PSNR statistics for this frame */
145 VPX_CODEC_CUSTOM_PKT = 256 /**< Algorithm extensions */
149 /*!\brief Encoder output packet
151 * This structure contains the different kinds of output data the encoder
152 * may produce while compressing a frame.
154 typedef struct vpx_codec_cx_pkt
156 enum vpx_codec_cx_pkt_kind kind; /**< packet variant */
161 void *buf; /**< compressed data buffer */
162 size_t sz; /**< length of compressed data */
163 vpx_codec_pts_t pts; /**< time stamp to show frame
164 (in timebase units) */
165 unsigned long duration; /**< duration to show frame
166 (in timebase units) */
167 vpx_codec_frame_flags_t flags; /**< flags for this frame */
168 int partition_id; /**< the partition id
169 defines the decoding order
170 of the partitions. Only
171 applicable when "output partition"
172 mode is enabled. First partition
175 } frame; /**< data for compressed frame packet */
176 struct vpx_fixed_buf twopass_stats; /**< data for two-pass packet */
179 unsigned int samples[4]; /**< Number of samples, total/y/u/v */
180 uint64_t sse[4]; /**< sum squared error, total/y/u/v */
181 double psnr[4]; /**< PSNR, total/y/u/v */
182 } psnr; /**< data for PSNR packet */
183 struct vpx_fixed_buf raw; /**< data for arbitrary packets */
185 /* This packet size is fixed to allow codecs to extend this
186 * interface without having to manage storage for raw packets,
187 * i.e., if it's smaller than 128 bytes, you can store in the
188 * packet list directly.
190 char pad[128 - sizeof(enum vpx_codec_cx_pkt_kind)]; /**< fixed sz */
191 } data; /**< packet data */
192 } vpx_codec_cx_pkt_t; /**< alias for struct vpx_codec_cx_pkt */
195 /*!\brief Rational Number
197 * This structure holds a fractional value.
199 typedef struct vpx_rational
201 int num; /**< fraction numerator */
202 int den; /**< fraction denominator */
203 } vpx_rational_t; /**< alias for struct vpx_rational */
206 /*!\brief Multi-pass Encoding Pass */
209 VPX_RC_ONE_PASS, /**< Single pass mode */
210 VPX_RC_FIRST_PASS, /**< First pass of multi-pass mode */
211 VPX_RC_LAST_PASS /**< Final pass of multi-pass mode */
215 /*!\brief Rate control mode */
218 VPX_VBR, /**< Variable Bit Rate (VBR) mode */
219 VPX_CBR, /**< Constant Bit Rate (CBR) mode */
220 VPX_CQ /**< Constant Quality (CQ) mode */
224 /*!\brief Keyframe placement mode.
226 * This enumeration determines whether keyframes are placed automatically by
227 * the encoder or whether this behavior is disabled. Older releases of this
228 * SDK were implemented such that VPX_KF_FIXED meant keyframes were disabled.
229 * This name is confusing for this behavior, so the new symbols to be used
230 * are VPX_KF_AUTO and VPX_KF_DISABLED.
234 VPX_KF_FIXED, /**< deprecated, implies VPX_KF_DISABLED */
235 VPX_KF_AUTO, /**< Encoder determines optimal placement automatically */
236 VPX_KF_DISABLED = 0 /**< Encoder does not place keyframes. */
240 /*!\brief Encoded Frame Flags
242 * This type indicates a bitfield to be passed to vpx_codec_encode(), defining
243 * per-frame boolean values. By convention, bits common to all codecs will be
244 * named VPX_EFLAG_*, and bits specific to an algorithm will be named
245 * /algo/_eflag_*. The lower order 16 bits are reserved for common use.
247 typedef long vpx_enc_frame_flags_t;
248 #define VPX_EFLAG_FORCE_KF (1<<0) /**< Force this frame to be a keyframe */
251 /*!\brief Encoder configuration structure
253 * This structure contains the encoder settings that have common representations
254 * across all codecs. This doesn't imply that all codecs support all features,
257 typedef struct vpx_codec_enc_cfg
260 * generic settings (g)
263 /*!\brief Algorithm specific "usage" value
265 * Algorithms may define multiple values for usage, which may convey the
266 * intent of how the application intends to use the stream. If this value
267 * is non-zero, consult the documentation for the codec to determine its
270 unsigned int g_usage;
273 /*!\brief Maximum number of threads to use
275 * For multi-threaded implementations, use no more than this number of
276 * threads. The codec may use fewer threads than allowed. The value
277 * 0 is equivalent to the value 1.
279 unsigned int g_threads;
282 /*!\brief Bitstream profile to use
284 * Some codecs support a notion of multiple bitstream profiles. Typically
285 * this maps to a set of features that are turned on or off. Often the
286 * profile to use is determined by the features of the intended decoder.
287 * Consult the documentation for the codec to determine the valid values
288 * for this parameter, or set to zero for a sane default.
290 unsigned int g_profile; /**< profile of bitstream to use */
294 /*!\brief Width of the frame
296 * This value identifies the presentation resolution of the frame,
297 * in pixels. Note that the frames passed as input to the encoder must
298 * have this resolution. Frames will be presented by the decoder in this
299 * resolution, independent of any spatial resampling the encoder may do.
304 /*!\brief Height of the frame
306 * This value identifies the presentation resolution of the frame,
307 * in pixels. Note that the frames passed as input to the encoder must
308 * have this resolution. Frames will be presented by the decoder in this
309 * resolution, independent of any spatial resampling the encoder may do.
314 /*!\brief Stream timebase units
316 * Indicates the smallest interval of time, in seconds, used by the stream.
317 * For fixed frame rate material, or variable frame rate material where
318 * frames are timed at a multiple of a given clock (ex: video capture),
319 * the \ref RECOMMENDED method is to set the timebase to the reciprocal
320 * of the frame rate (ex: 1001/30000 for 29.970 Hz NTSC). This allows the
321 * pts to correspond to the frame number, which can be handy. For
322 * re-encoding video from containers with absolute time timestamps, the
323 * \ref RECOMMENDED method is to set the timebase to that of the parent
324 * container or multimedia framework (ex: 1/1000 for ms, as in FLV).
326 struct vpx_rational g_timebase;
329 /*!\brief Enable error resilient modes.
331 * The error resilient bitfield indicates to the encoder which features
332 * it should enable to take measures for streaming over lossy or noisy
335 vpx_codec_er_flags_t g_error_resilient;
338 /*!\brief Multi-pass Encoding Mode
340 * This value should be set to the current phase for multi-pass encoding.
341 * For single pass, set to #VPX_RC_ONE_PASS.
343 enum vpx_enc_pass g_pass;
346 /*!\brief Allow lagged encoding
348 * If set, this value allows the encoder to consume a number of input
349 * frames before producing output frames. This allows the encoder to
350 * base decisions for the current frame on future frames. This does
351 * increase the latency of the encoding pipeline, so it is not appropriate
352 * in all situations (ex: realtime encoding).
354 * Note that this is a maximum value -- the encoder may produce frames
355 * sooner than the given limit. Set this value to 0 to disable this
358 unsigned int g_lag_in_frames;
362 * rate control settings (rc)
365 /*!\brief Temporal resampling configuration, if supported by the codec.
367 * Temporal resampling allows the codec to "drop" frames as a strategy to
368 * meet its target data rate. This can cause temporal discontinuities in
369 * the encoded video, which may appear as stuttering during playback. This
370 * trade-off is often acceptable, but for many applications is not. It can
371 * be disabled in these cases.
373 * Note that not all codecs support this feature. All vpx VPx codecs do.
374 * For other codecs, consult the documentation for that algorithm.
376 * This threshold is described as a percentage of the target data buffer.
377 * When the data buffer falls below this percentage of fullness, a
378 * dropped frame is indicated. Set the threshold to zero (0) to disable
381 unsigned int rc_dropframe_thresh;
384 /*!\brief Enable/disable spatial resampling, if supported by the codec.
386 * Spatial resampling allows the codec to compress a lower resolution
387 * version of the frame, which is then upscaled by the encoder to the
388 * correct presentation resolution. This increases visual quality at
389 * low data rates, at the expense of CPU time on the encoder/decoder.
391 unsigned int rc_resize_allowed;
394 /*!\brief Spatial resampling up watermark.
396 * This threshold is described as a percentage of the target data buffer.
397 * When the data buffer rises above this percentage of fullness, the
398 * encoder will step up to a higher resolution version of the frame.
400 unsigned int rc_resize_up_thresh;
403 /*!\brief Spatial resampling down watermark.
405 * This threshold is described as a percentage of the target data buffer.
406 * When the data buffer falls below this percentage of fullness, the
407 * encoder will step down to a lower resolution version of the frame.
409 unsigned int rc_resize_down_thresh;
412 /*!\brief Rate control algorithm to use.
414 * Indicates whether the end usage of this stream is to be streamed over
415 * a bandwidth constrained link, indicating that Constant Bit Rate (CBR)
416 * mode should be used, or whether it will be played back on a high
417 * bandwidth link, as from a local disk, where higher variations in
418 * bitrate are acceptable.
420 enum vpx_rc_mode rc_end_usage;
423 /*!\brief Two-pass stats buffer.
425 * A buffer containing all of the stats packets produced in the first
426 * pass, concatenated.
428 struct vpx_fixed_buf rc_twopass_stats_in;
431 /*!\brief Target data rate
433 * Target bandwidth to use for this stream, in kilobits per second.
435 unsigned int rc_target_bitrate;
443 /*!\brief Minimum (Best Quality) Quantizer
445 * The quantizer is the most direct control over the quality of the
446 * encoded image. The range of valid values for the quantizer is codec
447 * specific. Consult the documentation for the codec to determine the
448 * values to use. To determine the range programmatically, call
449 * vpx_codec_enc_config_default() with a usage value of 0.
451 unsigned int rc_min_quantizer;
454 /*!\brief Maximum (Worst 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_max_quantizer;
470 /*!\brief Rate control adaptation undershoot control
472 * This value, expressed as a percentage of the target bitrate,
473 * controls the maximum allowed adaptation speed of the codec.
474 * This factor controls the maximum amount of bits that can
475 * be subtracted from the target bitrate in order to compensate
476 * for prior overshoot.
478 * Valid values in the range 0-1000.
480 unsigned int rc_undershoot_pct;
483 /*!\brief Rate control adaptation overshoot control
485 * This value, expressed as a percentage of the target bitrate,
486 * controls the maximum allowed adaptation speed of the codec.
487 * This factor controls the maximum amount of bits that can
488 * be added to the target bitrate in order to compensate for
491 * Valid values in the range 0-1000.
493 unsigned int rc_overshoot_pct;
497 * decoder buffer model parameters
501 /*!\brief Decoder Buffer Size
503 * This value indicates the amount of data that may be buffered by the
504 * decoding application. Note that this value is expressed in units of
505 * time (milliseconds). For example, a value of 5000 indicates that the
506 * client will buffer (at least) 5000ms worth of encoded data. Use the
507 * target bitrate (#rc_target_bitrate) to convert to bits/bytes, if
510 unsigned int rc_buf_sz;
513 /*!\brief Decoder Buffer Initial Size
515 * This value indicates the amount of data that will be buffered by the
516 * decoding application prior to beginning playback. This value is
517 * expressed in units of time (milliseconds). Use the target bitrate
518 * (#rc_target_bitrate) to convert to bits/bytes, if necessary.
520 unsigned int rc_buf_initial_sz;
523 /*!\brief Decoder Buffer Optimal Size
525 * This value indicates the amount of data that the encoder should try
526 * to maintain in the decoder's buffer. This value is expressed in units
527 * of time (milliseconds). Use the target bitrate (#rc_target_bitrate)
528 * to convert to bits/bytes, if necessary.
530 unsigned int rc_buf_optimal_sz;
534 * 2 pass rate control parameters
538 /*!\brief Two-pass mode CBR/VBR bias
540 * Bias, expressed on a scale of 0 to 100, for determining target size
541 * for the current frame. The value 0 indicates the optimal CBR mode
542 * value should be used. The value 100 indicates the optimal VBR mode
543 * value should be used. Values in between indicate which way the
544 * encoder should "lean."
546 unsigned int rc_2pass_vbr_bias_pct; /**< RC mode bias between CBR and VBR(0-100: 0->CBR, 100->VBR) */
549 /*!\brief Two-pass mode per-GOP minimum bitrate
551 * This value, expressed as a percentage of the target bitrate, indicates
552 * the minimum bitrate to be used for a single GOP (aka "section")
554 unsigned int rc_2pass_vbr_minsection_pct;
557 /*!\brief Two-pass mode per-GOP maximum bitrate
559 * This value, expressed as a percentage of the target bitrate, indicates
560 * the maximum bitrate to be used for a single GOP (aka "section")
562 unsigned int rc_2pass_vbr_maxsection_pct;
566 * keyframing settings (kf)
569 /*!\brief Keyframe placement mode
571 * This value indicates whether the encoder should place keyframes at a
572 * fixed interval, or determine the optimal placement automatically
573 * (as governed by the #kf_min_dist and #kf_max_dist parameters)
575 enum vpx_kf_mode kf_mode;
578 /*!\brief Keyframe minimum interval
580 * This value, expressed as a number of frames, prevents the encoder from
581 * placing a keyframe nearer than kf_min_dist to the previous keyframe. At
582 * least kf_min_dist frames non-keyframes will be coded before the next
583 * keyframe. Set kf_min_dist equal to kf_max_dist for a fixed interval.
585 unsigned int kf_min_dist;
588 /*!\brief Keyframe maximum interval
590 * This value, expressed as a number of frames, forces the encoder to code
591 * a keyframe if one has not been coded in the last kf_max_dist frames.
592 * A value of 0 implies all frames will be keyframes. Set kf_min_dist
593 * equal to kf_max_dist for a fixed interval.
595 unsigned int kf_max_dist;
598 * Temporal scalability settings (ts)
601 /*!\brief Number of coding layers
603 * This value specifies the number of coding layers to be used.
605 unsigned int ts_number_layers;
607 /*!\brief Target bitrate for each layer
609 * These values specify the target coding bitrate for each coding layer.
611 unsigned int ts_target_bitrate[MAX_LAYERS];
613 /*!\brief Frame rate decimation factor for each layer
615 * These values specify the frame rate decimation factors to apply
618 unsigned int ts_rate_decimator[MAX_LAYERS];
620 /*!\brief Length of the sequence defining frame layer membership
622 * This value specifies the length of the sequence that defines the
623 * membership of frames to layers. For example, if ts_periodicity=8 then
624 * frames are assigned to coding layers with a repeated sequence of
627 unsigned int ts_periodicity;
629 /*!\brief Template defining the membership of frames to coding layers
631 * This array defines the membership of frames to coding layers. For a
632 * 2-layer encoding that assigns even numbered frames to one layer (0)
633 * and odd numbered frames to a second layer (1) with ts_periodicity=8,
634 * then ts_layer_id = (0,1,0,1,0,1,0,1).
636 unsigned int ts_layer_id[MAX_PERIODICITY];
637 } vpx_codec_enc_cfg_t; /**< alias for struct vpx_codec_enc_cfg */
640 /*!\brief Initialize an encoder instance
642 * Initializes a encoder context using the given interface. Applications
643 * should call the vpx_codec_enc_init convenience macro instead of this
644 * function directly, to ensure that the ABI version number parameter
645 * is properly initialized.
647 * In XMA mode (activated by setting VPX_CODEC_USE_XMA in the flags
648 * parameter), the storage pointed to by the cfg parameter must be
649 * kept readable and stable until all memory maps have been set.
651 * \param[in] ctx Pointer to this instance's context.
652 * \param[in] iface Pointer to the algorithm interface to use.
653 * \param[in] cfg Configuration to use, if known. May be NULL.
654 * \param[in] flags Bitfield of VPX_CODEC_USE_* flags
655 * \param[in] ver ABI version number. Must be set to
656 * VPX_ENCODER_ABI_VERSION
657 * \retval #VPX_CODEC_OK
658 * The decoder algorithm initialized.
659 * \retval #VPX_CODEC_MEM_ERROR
660 * Memory allocation failed.
662 vpx_codec_err_t vpx_codec_enc_init_ver(vpx_codec_ctx_t *ctx,
663 vpx_codec_iface_t *iface,
664 vpx_codec_enc_cfg_t *cfg,
665 vpx_codec_flags_t flags,
669 /*!\brief Convenience macro for vpx_codec_enc_init_ver()
671 * Ensures the ABI version parameter is properly set.
673 #define vpx_codec_enc_init(ctx, iface, cfg, flags) \
674 vpx_codec_enc_init_ver(ctx, iface, cfg, flags, VPX_ENCODER_ABI_VERSION)
677 /*!\brief Initialize multi-encoder instance
679 * Initializes multi-encoder context using the given interface.
680 * Applications should call the vpx_codec_enc_init_multi convenience macro
681 * instead of this function directly, to ensure that the ABI version number
682 * parameter is properly initialized.
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.
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] num_enc Total number of encoders.
692 * \param[in] flags Bitfield of VPX_CODEC_USE_* flags
693 * \param[in] dsf Pointer to down-sampling factors.
694 * \param[in] ver ABI version number. Must be set to
695 * VPX_ENCODER_ABI_VERSION
696 * \retval #VPX_CODEC_OK
697 * The decoder algorithm initialized.
698 * \retval #VPX_CODEC_MEM_ERROR
699 * Memory allocation failed.
701 vpx_codec_err_t vpx_codec_enc_init_multi_ver(vpx_codec_ctx_t *ctx,
702 vpx_codec_iface_t *iface,
703 vpx_codec_enc_cfg_t *cfg,
705 vpx_codec_flags_t flags,
710 /*!\brief Convenience macro for vpx_codec_enc_init_multi_ver()
712 * Ensures the ABI version parameter is properly set.
714 #define vpx_codec_enc_init_multi(ctx, iface, cfg, num_enc, flags, dsf) \
715 vpx_codec_enc_init_multi_ver(ctx, iface, cfg, num_enc, flags, dsf, \
716 VPX_ENCODER_ABI_VERSION)
719 /*!\brief Get a default configuration
721 * Initializes a encoder configuration structure with default values. Supports
722 * the notion of "usages" so that an algorithm may offer different default
723 * settings depending on the user's intended goal. This function \ref SHOULD
724 * be called by all applications to initialize the configuration structure
725 * before specializing the configuration with application specific values.
727 * \param[in] iface Pointer to the algorithm interface to use.
728 * \param[out] cfg Configuration buffer to populate
729 * \param[in] usage End usage. Set to 0 or use codec specific values.
731 * \retval #VPX_CODEC_OK
732 * The configuration was populated.
733 * \retval #VPX_CODEC_INCAPABLE
734 * Interface is not an encoder interface.
735 * \retval #VPX_CODEC_INVALID_PARAM
736 * A parameter was NULL, or the usage value was not recognized.
738 vpx_codec_err_t vpx_codec_enc_config_default(vpx_codec_iface_t *iface,
739 vpx_codec_enc_cfg_t *cfg,
743 /*!\brief Set or change configuration
745 * Reconfigures an encoder instance according to the given configuration.
747 * \param[in] ctx Pointer to this instance's context
748 * \param[in] cfg Configuration buffer to use
750 * \retval #VPX_CODEC_OK
751 * The configuration was populated.
752 * \retval #VPX_CODEC_INCAPABLE
753 * Interface is not an encoder interface.
754 * \retval #VPX_CODEC_INVALID_PARAM
755 * A parameter was NULL, or the usage value was not recognized.
757 vpx_codec_err_t vpx_codec_enc_config_set(vpx_codec_ctx_t *ctx,
758 const vpx_codec_enc_cfg_t *cfg);
761 /*!\brief Get global stream headers
763 * Retrieves a stream level global header packet, if supported by the codec.
765 * \param[in] ctx Pointer to this instance's context
768 * Encoder does not support global header
770 * Pointer to buffer containing global header packet
772 vpx_fixed_buf_t *vpx_codec_get_global_headers(vpx_codec_ctx_t *ctx);
775 #define VPX_DL_REALTIME (1) /**< deadline parameter analogous to
776 * VPx REALTIME mode. */
777 #define VPX_DL_GOOD_QUALITY (1000000) /**< deadline parameter analogous to
778 * VPx GOOD QUALITY mode. */
779 #define VPX_DL_BEST_QUALITY (0) /**< deadline parameter analogous to
780 * VPx BEST QUALITY mode. */
781 /*!\brief Encode a frame
783 * Encodes a video frame at the given "presentation time." The presentation
784 * time stamp (PTS) \ref MUST be strictly increasing.
786 * The encoder supports the notion of a soft real-time deadline. Given a
787 * non-zero value to the deadline parameter, the encoder will make a "best
788 * effort" guarantee to return before the given time slice expires. It is
789 * implicit that limiting the available time to encode will degrade the
790 * output quality. The encoder can be given an unlimited time to produce the
791 * best possible frame by specifying a deadline of '0'. This deadline
792 * supercedes the VPx notion of "best quality, good quality, realtime".
793 * Applications that wish to map these former settings to the new deadline
794 * based system can use the symbols #VPX_DL_REALTIME, #VPX_DL_GOOD_QUALITY,
795 * and #VPX_DL_BEST_QUALITY.
797 * When the last frame has been passed to the encoder, this function should
798 * continue to be called, with the img parameter set to NULL. This will
799 * signal the end-of-stream condition to the encoder and allow it to encode
800 * any held buffers. Encoding is complete when vpx_codec_encode() is called
801 * and vpx_codec_get_cx_data() returns no data.
803 * \param[in] ctx Pointer to this instance's context
804 * \param[in] img Image data to encode, NULL to flush.
805 * \param[in] pts Presentation time stamp, in timebase units.
806 * \param[in] duration Duration to show frame, in timebase units.
807 * \param[in] flags Flags to use for encoding this frame.
808 * \param[in] deadline Time to spend encoding, in microseconds. (0=infinite)
810 * \retval #VPX_CODEC_OK
811 * The configuration was populated.
812 * \retval #VPX_CODEC_INCAPABLE
813 * Interface is not an encoder interface.
814 * \retval #VPX_CODEC_INVALID_PARAM
815 * A parameter was NULL, the image format is unsupported, etc.
817 vpx_codec_err_t vpx_codec_encode(vpx_codec_ctx_t *ctx,
818 const vpx_image_t *img,
820 unsigned long duration,
821 vpx_enc_frame_flags_t flags,
822 unsigned long deadline);
824 /*!\brief Set compressed data output buffer
826 * Sets the buffer that the codec should output the compressed data
827 * into. This call effectively sets the buffer pointer returned in the
828 * next VPX_CODEC_CX_FRAME_PKT packet. Subsequent packets will be
829 * appended into this buffer. The buffer is preserved across frames,
830 * so applications must periodically call this function after flushing
831 * the accumulated compressed data to disk or to the network to reset
832 * the pointer to the buffer's head.
834 * `pad_before` bytes will be skipped before writing the compressed
835 * data, and `pad_after` bytes will be appended to the packet. The size
836 * of the packet will be the sum of the size of the actual compressed
837 * data, pad_before, and pad_after. The padding bytes will be preserved
840 * Note that calling this function does not guarantee that the returned
841 * compressed data will be placed into the specified buffer. In the
842 * event that the encoded data will not fit into the buffer provided,
843 * the returned packet \ref MAY point to an internal buffer, as it would
844 * if this call were never used. In this event, the output packet will
845 * NOT have any padding, and the application must free space and copy it
846 * to the proper place. This is of particular note in configurations
847 * that may output multiple packets for a single encoded frame (e.g., lagged
848 * encoding) or if the application does not reset the buffer periodically.
850 * Applications may restore the default behavior of the codec providing
851 * the compressed data buffer by calling this function with a NULL
854 * Applications \ref MUSTNOT call this function during iteration of
855 * vpx_codec_get_cx_data().
857 * \param[in] ctx Pointer to this instance's context
858 * \param[in] buf Buffer to store compressed data into
859 * \param[in] pad_before Bytes to skip before writing compressed data
860 * \param[in] pad_after Bytes to skip after writing compressed data
862 * \retval #VPX_CODEC_OK
863 * The buffer was set successfully.
864 * \retval #VPX_CODEC_INVALID_PARAM
865 * A parameter was NULL, the image format is unsupported, etc.
867 vpx_codec_err_t vpx_codec_set_cx_data_buf(vpx_codec_ctx_t *ctx,
868 const vpx_fixed_buf_t *buf,
869 unsigned int pad_before,
870 unsigned int pad_after);
873 /*!\brief Encoded data iterator
875 * Iterates over a list of data packets to be passed from the encoder to the
876 * application. The different kinds of packets available are enumerated in
877 * #vpx_codec_cx_pkt_kind.
879 * #VPX_CODEC_CX_FRAME_PKT packets should be passed to the application's
880 * muxer. Multiple compressed frames may be in the list.
881 * #VPX_CODEC_STATS_PKT packets should be appended to a global buffer.
883 * The application \ref MUST silently ignore any packet kinds that it does
884 * not recognize or support.
886 * The data buffers returned from this function are only guaranteed to be
887 * valid until the application makes another call to any vpx_codec_* function.
889 * \param[in] ctx Pointer to this instance's context
890 * \param[in,out] iter Iterator storage, initialized to NULL
892 * \return Returns a pointer to an output data packet (compressed frame data,
893 * two-pass statistics, etc.) or NULL to signal end-of-list.
896 const vpx_codec_cx_pkt_t *vpx_codec_get_cx_data(vpx_codec_ctx_t *ctx,
897 vpx_codec_iter_t *iter);
900 /*!\brief Get Preview Frame
902 * Returns an image that can be used as a preview. Shows the image as it would
903 * exist at the decompressor. The application \ref MUST NOT write into this
906 * \param[in] ctx Pointer to this instance's context
908 * \return Returns a pointer to a preview image, or NULL if no image is
912 const vpx_image_t *vpx_codec_get_preview_frame(vpx_codec_ctx_t *ctx);
915 /*!@} - end defgroup encoder*/