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 11 12 /*!\defgroup encoder Encoder Algorithm Interface 13 * \ingroup codec 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. 17 * @{ 18 */ 19 20 /*!\file vpx_encoder.h 21 * \brief Describes the encoder algorithm interface to applications. 22 * 23 * This file describes the interface between an application and a 24 * video encoder algorithm. 25 * 26 */ 27 #ifdef __cplusplus 28 extern "C" { 29 #endif 30 31 #ifndef VPX_ENCODER_H 32 #define VPX_ENCODER_H 33 #include "vpx_codec.h" 34 35 36 /*!\brief Current ABI version number 37 * 38 * \internal 39 * If this file is altered in any way that changes the ABI, this value 40 * must be bumped. Examples include, but are not limited to, changing 41 * types, removing or reassigning enums, adding/removing/rearranging 42 * fields to structures 43 */ 44 #define VPX_ENCODER_ABI_VERSION (2 + VPX_CODEC_ABI_VERSION) /**<\hideinitializer*/ 45 46 47 /*! \brief Encoder capabilities bitfield 48 * 49 * Each encoder advertises the capabilities it supports as part of its 50 * ::vpx_codec_iface_t interface structure. Capabilities are extra 51 * interfaces or functionality, and are not required to be supported 52 * by an encoder. 53 * 54 * The available flags are specifiedby VPX_CODEC_CAP_* defines. 55 */ 56 #define VPX_CODEC_CAP_PSNR 0x10000 /**< Can issue PSNR packets */ 57 58 59 /*! \brief Initialization-time Feature Enabling 60 * 61 * Certain codec features must be known at initialization time, to allow 62 * for proper memory allocation. 63 * 64 * The available flags are specified by VPX_CODEC_USE_* defines. 65 */ 66 #define VPX_CODEC_USE_PSNR 0x10000 /**< Calculate PSNR on each frame */ 67 68 69 /*!\brief Generic fixed size buffer structure 70 * 71 * This structure is able to hold a reference to any fixed size buffer. 72 */ 73 typedef struct vpx_fixed_buf 74 { 75 void *buf; /**< Pointer to the data */ 76 size_t sz; /**< Length of the buffer, in chars */ 77 } vpx_fixed_buf_t; /**< alias for struct vpx_fixed_buf */ 78 79 80 /*!\brief Time Stamp Type 81 * 82 * An integer, which when multiplied by the stream's time base, provides 83 * the absolute time of a sample. 84 */ 85 typedef int64_t vpx_codec_pts_t; 86 87 88 /*!\brief Compressed Frame Flags 89 * 90 * This type represents a bitfield containing information about a compressed 91 * frame that may be useful to an application. The most significant 16 bits 92 * can be used by an algorithm to provide additional detail, for example to 93 * support frame types that are codec specific (MPEG-1 D-frames for example) 94 */ 95 typedef uint32_t vpx_codec_frame_flags_t; 96 #define VPX_FRAME_IS_KEY 0x1 /**< frame is the start of a GOP */ 97 #define VPX_FRAME_IS_DROPPABLE 0x2 /**< frame can be dropped without affecting 98 the stream (no future frame depends on 99 this one) */ 100 #define VPX_FRAME_IS_INVISIBLE 0x4 /**< frame should be decoded but will not 101 be shown */ 102 103 104 /*!\brief Encoder output packet variants 105 * 106 * This enumeration lists the different kinds of data packets that can be 107 * returned by calls to vpx_codec_get_cx_data(). Algorithms \ref MAY 108 * extend this list to provide additional functionality. 109 */ 110 enum vpx_codec_cx_pkt_kind 111 { 112 VPX_CODEC_CX_FRAME_PKT, /**< Compressed video frame */ 113 VPX_CODEC_STATS_PKT, /**< Two-pass statistics for this frame */ 114 VPX_CODEC_PSNR_PKT, /**< PSNR statistics for this frame */ 115 VPX_CODEC_CUSTOM_PKT = 256 /**< Algorithm extensions */ 116 }; 117 118 119 /*!\brief Encoder output packet 120 * 121 * This structure contains the different kinds of output data the encoder 122 * may produce while compressing a frame. 123 */ 124 typedef struct vpx_codec_cx_pkt 125 { 126 enum vpx_codec_cx_pkt_kind kind; /**< packet variant */ 127 union 128 { 129 struct 130 { 131 void *buf; /**< compressed data buffer */ 132 size_t sz; /**< length of compressed data */ 133 vpx_codec_pts_t pts; /**< time stamp to show frame 134 (in timebase units) */ 135 unsigned long duration; /**< duration to show frame 136 (in timebase units) */ 137 vpx_codec_frame_flags_t flags; /**< flags for this frame */ 138 } frame; /**< data for compressed frame packet */ 139 struct vpx_fixed_buf twopass_stats; /**< data for two-pass packet */ 140 struct vpx_psnr_pkt 141 { 142 unsigned int samples[4]; /**< Number of samples, total/y/u/v */ 143 uint64_t sse[4]; /**< sum squared error, total/y/u/v */ 144 double psnr[4]; /**< PSNR, total/y/u/v */ 145 } psnr; /**< data for PSNR packet */ 146 struct vpx_fixed_buf raw; /**< data for arbitrary packets */ 147 148 /* This packet size is fixed to allow codecs to extend this 149 * interface without having to manage storage for raw packets, 150 * ie if it's smaller than 128 bytes, you can store in the 151 * packet list directly. 152 */ 153 char pad[128 - sizeof(enum vpx_codec_cx_pkt_kind)]; /**< fixed sz */ 154 } data; /**< packet data */ 155 } vpx_codec_cx_pkt_t; /**< alias for struct vpx_codec_cx_pkt */ 156 157 158 /*!\brief Rational Number 159 * 160 * This structure holds a fractional value. 161 */ 162 typedef struct vpx_rational 163 { 164 int num; /**< fraction numerator */ 165 int den; /**< fraction denominator */ 166 } vpx_rational_t; /**< alias for struct vpx_rational */ 167 168 169 /*!\brief Multi-pass Encoding Pass */ 170 enum vpx_enc_pass 171 { 172 VPX_RC_ONE_PASS, /**< Single pass mode */ 173 VPX_RC_FIRST_PASS, /**< First pass of multi-pass mode */ 174 VPX_RC_LAST_PASS /**< Final pass of multi-pass mode */ 175 }; 176 177 178 /*!\brief Rate control mode */ 179 enum vpx_rc_mode 180 { 181 VPX_VBR, /**< Variable Bit Rate (VBR) mode */ 182 VPX_CBR /**< Constant Bit Rate (CBR) mode */ 183 }; 184 185 186 /*!\brief Keyframe placement mode. 187 * 188 * This enumeration determines whether keyframes are placed automatically by 189 * the encoder or whether this behavior is disabled. Older releases of this 190 * SDK were implemented such that VPX_KF_FIXED meant keyframes were disabled. 191 * This name is confusing for this behavior, so the new symbols to be used 192 * are VPX_KF_AUTO and VPX_KF_DISABLED. 193 */ 194 enum vpx_kf_mode 195 { 196 VPX_KF_FIXED, /**< deprecated, implies VPX_KF_DISABLED */ 197 VPX_KF_AUTO, /**< Encoder determines optimal placement automatically */ 198 VPX_KF_DISABLED = 0 /**< Encoder does not place keyframes. */ 199 }; 200 201 202 /*!\brief Encoded Frame Flags 203 * 204 * This type indicates a bitfield to be passed to vpx_codec_encode(), defining 205 * per-frame boolean values. By convention, bits common to all codecs will be 206 * named VPX_EFLAG_*, and bits specific to an algorithm will be named 207 * /algo/_eflag_*. The lower order 16 bits are reserved for common use. 208 */ 209 typedef long vpx_enc_frame_flags_t; 210 #define VPX_EFLAG_FORCE_KF (1<<0) /**< Force this frame to be a keyframe */ 211 212 213 /*!\brief Encoder configuration structure 214 * 215 * This structure contains the encoder settings that have common representations 216 * across all codecs. This doesn't imply that all codecs support all features, 217 * however. 218 */ 219 typedef struct vpx_codec_enc_cfg 220 { 221 /* 222 * generic settings (g) 223 */ 224 225 /*!\brief Algorithm specific "usage" value 226 * 227 * Algorithms may define multiple values for usage, which may convey the 228 * intent of how the application intends to use the stream. If this value 229 * is non-zero, consult the documentation for the codec to determine its 230 * meaning. 231 */ 232 unsigned int g_usage; 233 234 235 /*!\brief Maximum number of threads to use 236 * 237 * For multi-threaded implementations, use no more than this number of 238 * threads. The codec may use fewer threads than allowed. The value 239 * 0 is equivalent to the value 1. 240 */ 241 unsigned int g_threads; 242 243 244 /*!\brief Bitstream profile to use 245 * 246 * Some codecs support a notion of multiple bitstream profiles. Typically 247 * this maps to a set of features that are turned on or off. Often the 248 * profile to use is determined by the features of the intended decoder. 249 * Consult the documentation for the codec to determine the valid values 250 * for this parameter, or set to zero for a sane default. 251 */ 252 unsigned int g_profile; /**< profile of bitstream to use */ 253 254 255 256 /*!\brief Width of the frame 257 * 258 * This value identifies the presentation resolution of the frame, 259 * in pixels. Note that the frames passed as input to the encoder must 260 * have this resolution. Frames will be presented by the decoder in this 261 * resolution, independent of any spatial resampling the encoder may do. 262 */ 263 unsigned int g_w; 264 265 266 /*!\brief Height of the frame 267 * 268 * This value identifies the presentation resolution of the frame, 269 * in pixels. Note that the frames passed as input to the encoder must 270 * have this resolution. Frames will be presented by the decoder in this 271 * resolution, independent of any spatial resampling the encoder may do. 272 */ 273 unsigned int g_h; 274 275 276 /*!\brief Stream timebase units 277 * 278 * Indicates the smallest interval of time, in seconds, used by the stream. 279 * For fixed frame rate material, or variable frame rate material where 280 * frames are timed at a multiple of a given clock (ex: video capture), 281 * the \ref RECOMMENDED method is to set the timebase to the reciprocal 282 * of the frame rate (ex: 1001/30000 for 29.970 Hz NTSC). This allows the 283 * pts to correspond to the frame number, which can be handy. For 284 * re-encoding video from containers with absolute time timestamps, the 285 * \ref RECOMMENDED method is to set the timebase to that of the parent 286 * container or multimedia framework (ex: 1/1000 for ms, as in FLV). 287 */ 288 struct vpx_rational g_timebase; 289 290 291 /*!\brief Enable error resilient mode. 292 * 293 * Error resilient mode indicates to the encoder that it should take 294 * measures appropriate for streaming over lossy or noisy links, if 295 * possible. Set to 1 to enable this feature, 0 to disable it. 296 */ 297 unsigned int g_error_resilient; 298 299 300 /*!\brief Multi-pass Encoding Mode 301 * 302 * This value should be set to the current phase for multi-pass encoding. 303 * For single pass, set to #VPX_RC_ONE_PASS. 304 */ 305 enum vpx_enc_pass g_pass; 306 307 308 /*!\brief Allow lagged encoding 309 * 310 * If set, this value allows the encoder to consume a number of input 311 * frames before producing output frames. This allows the encoder to 312 * base decisions for the current frame on future frames. This does 313 * increase the latency of the encoding pipeline, so it is not appropriate 314 * in all situations (ex: realtime encoding). 315 * 316 * Note that this is a maximum value -- the encoder may produce frames 317 * sooner than the given limit. Set this value to 0 to disable this 318 * feature. 319 */ 320 unsigned int g_lag_in_frames; 321 322 323 /* 324 * rate control settings (rc) 325 */ 326 327 /*!\brief Temporal resampling configuration, if supported by the codec. 328 * 329 * Temporal resampling allows the codec to "drop" frames as a strategy to 330 * meet its target data rate. This can cause temporal discontinuities in 331 * the encoded video, which may appear as stuttering during playback. This 332 * trade-off is often acceptable, but for many applications is not. It can 333 * be disabled in these cases. 334 * 335 * Note that not all codecs support this feature. All vpx VPx codecs do. 336 * For other codecs, consult the documentation for that algorithm. 337 * 338 * This threshold is described as a percentage of the target data buffer. 339 * When the data buffer falls below this percentage of fullness, a 340 * dropped frame is indicated. Set the threshold to zero (0) to disable 341 * this feature. 342 */ 343 unsigned int rc_dropframe_thresh; 344 345 346 /*!\brief Enable/disable spatial resampling, if supported by the codec. 347 * 348 * Spatial resampling allows the codec to compress a lower resolution 349 * version of the frame, which is then upscaled by the encoder to the 350 * correct presentation resolution. This increases visual quality at 351 * low data rates, at the expense of CPU time on the encoder/decoder. 352 */ 353 unsigned int rc_resize_allowed; 354 355 356 /*!\brief Spatial resampling up watermark. 357 * 358 * This threshold is described as a percentage of the target data buffer. 359 * When the data buffer rises above this percentage of fullness, the 360 * encoder will step up to a higher resolution version of the frame. 361 */ 362 unsigned int rc_resize_up_thresh; 363 364 365 /*!\brief Spatial resampling down watermark. 366 * 367 * This threshold is described as a percentage of the target data buffer. 368 * When the data buffer falls below this percentage of fullness, the 369 * encoder will step down to a lower resolution version of the frame. 370 */ 371 unsigned int rc_resize_down_thresh; 372 373 374 /*!\brief Rate control algorithm to use. 375 * 376 * Indicates whether the end usage of this stream is to be streamed over 377 * a bandwidth constrained link, indicating that Constant Bit Rate (CBR) 378 * mode should be used, or whether it will be played back on a high 379 * bandwidth link, as from a local disk, where higher variations in 380 * bitrate are acceptable. 381 */ 382 enum vpx_rc_mode rc_end_usage; 383 384 385 /*!\brief Two-pass stats buffer. 386 * 387 * A buffer containing all of the stats packets produced in the first 388 * pass, concatenated. 389 */ 390 struct vpx_fixed_buf rc_twopass_stats_in; 391 392 393 /*!\brief Target data rate 394 * 395 * Target bandwidth to use for this stream, in kilobits per second. 396 */ 397 unsigned int rc_target_bitrate; 398 399 400 /* 401 * quantizer settings 402 */ 403 404 405 /*!\brief Minimum (Best Quality) Quantizer 406 * 407 * The quantizer is the most direct control over the quality of the 408 * encoded image. The range of valid values for the quantizer is codec 409 * specific. Consult the documentation for the codec to determine the 410 * values to use. To determine the range programmatically, call 411 * vpx_codec_enc_config_default() with a usage value of 0. 412 */ 413 unsigned int rc_min_quantizer; 414 415 416 /*!\brief Maximum (Worst Quality) Quantizer 417 * 418 * The quantizer is the most direct control over the quality of the 419 * encoded image. The range of valid values for the quantizer is codec 420 * specific. Consult the documentation for the codec to determine the 421 * values to use. To determine the range programmatically, call 422 * vpx_codec_enc_config_default() with a usage value of 0. 423 */ 424 unsigned int rc_max_quantizer; 425 426 427 /* 428 * bitrate tolerance 429 */ 430 431 432 /*!\brief Rate control undershoot tolerance 433 * 434 * This value, expressed as a percentage of the target bitrate, describes 435 * the target bitrate for easier frames, allowing bits to be saved for 436 * harder frames. Set to zero to use the codec default. 437 */ 438 unsigned int rc_undershoot_pct; 439 440 441 /*!\brief Rate control overshoot tolerance 442 * 443 * This value, expressed as a percentage of the target bitrate, describes 444 * the maximum allowed bitrate for a given frame. Set to zero to use the 445 * codec default. 446 */ 447 unsigned int rc_overshoot_pct; 448 449 450 /* 451 * decoder buffer model parameters 452 */ 453 454 455 /*!\brief Decoder Buffer Size 456 * 457 * This value indicates the amount of data that may be buffered by the 458 * decoding application. Note that this value is expressed in units of 459 * time (milliseconds). For example, a value of 5000 indicates that the 460 * client will buffer (at least) 5000ms worth of encoded data. Use the 461 * target bitrate (#rc_target_bitrate) to convert to bits/bytes, if 462 * necessary. 463 */ 464 unsigned int rc_buf_sz; 465 466 467 /*!\brief Decoder Buffer Initial Size 468 * 469 * This value indicates the amount of data that will be buffered by the 470 * decoding application prior to beginning playback. This value is 471 * expressed in units of time (milliseconds). Use the target bitrate 472 * (#rc_target_bitrate) to convert to bits/bytes, if necessary. 473 */ 474 unsigned int rc_buf_initial_sz; 475 476 477 /*!\brief Decoder Buffer Optimal Size 478 * 479 * This value indicates the amount of data that the encoder should try 480 * to maintain in the decoder's buffer. This value is expressed in units 481 * of time (milliseconds). Use the target bitrate (#rc_target_bitrate) 482 * to convert to bits/bytes, if necessary. 483 */ 484 unsigned int rc_buf_optimal_sz; 485 486 487 /* 488 * 2 pass rate control parameters 489 */ 490 491 492 /*!\brief Two-pass mode CBR/VBR bias 493 * 494 * Bias, expressed on a scale of 0 to 100, for determining target size 495 * for the current frame. The value 0 indicates the optimal CBR mode 496 * value should be used. The value 100 indicates the optimal VBR mode 497 * value should be used. Values in between indicate which way the 498 * encoder should "lean." 499 */ 500 unsigned int rc_2pass_vbr_bias_pct; /**< RC mode bias between CBR and VBR(0-100: 0->CBR, 100->VBR) */ 501 502 503 /*!\brief Two-pass mode per-GOP minimum bitrate 504 * 505 * This value, expressed as a percentage of the target bitrate, indicates 506 * the minimum bitrate to be used for a single GOP (aka "section") 507 */ 508 unsigned int rc_2pass_vbr_minsection_pct; 509 510 511 /*!\brief Two-pass mode per-GOP maximum bitrate 512 * 513 * This value, expressed as a percentage of the target bitrate, indicates 514 * the maximum bitrate to be used for a single GOP (aka "section") 515 */ 516 unsigned int rc_2pass_vbr_maxsection_pct; 517 518 519 /* 520 * keyframing settings (kf) 521 */ 522 523 /*!\brief Keyframe placement mode 524 * 525 * This value indicates whether the encoder should place keyframes at a 526 * fixed interval, or determine the optimal placement automatically 527 * (as governed by the #kf_min_dist and #kf_max_dist parameters) 528 */ 529 enum vpx_kf_mode kf_mode; 530 531 532 /*!\brief Keyframe minimum interval 533 * 534 * This value, expressed as a number of frames, prevents the encoder from 535 * placing a keyframe nearer than kf_min_dist to the previous keyframe. At 536 * least kf_min_dist frames non-keyframes will be coded before the next 537 * keyframe. Set kf_min_dist equal to kf_max_dist for a fixed interval. 538 */ 539 unsigned int kf_min_dist; 540 541 542 /*!\brief Keyframe maximum interval 543 * 544 * This value, expressed as a number of frames, forces the encoder to code 545 * a keyframe if one has not been coded in the last kf_max_dist frames. 546 * A value of 0 implies all frames will be keyframes. Set kf_min_dist 547 * equal to kf_max_dist for a fixed interval. 548 */ 549 unsigned int kf_max_dist; 550 551 } vpx_codec_enc_cfg_t; /**< alias for struct vpx_codec_enc_cfg */ 552 553 554 /*!\brief Initialize an encoder instance 555 * 556 * Initializes a encoder context using the given interface. Applications 557 * should call the vpx_codec_enc_init convenience macro instead of this 558 * function directly, to ensure that the ABI version number parameter 559 * is properly initialized. 560 * 561 * In XMA mode (activated by setting VPX_CODEC_USE_XMA in the flags 562 * parameter), the storage pointed to by the cfg parameter must be 563 * kept readable and stable until all memory maps have been set. 564 * 565 * \param[in] ctx Pointer to this instance's context. 566 * \param[in] iface Pointer to the algorithm interface to use. 567 * \param[in] cfg Configuration to use, if known. May be NULL. 568 * \param[in] flags Bitfield of VPX_CODEC_USE_* flags 569 * \param[in] ver ABI version number. Must be set to 570 * VPX_ENCODER_ABI_VERSION 571 * \retval #VPX_CODEC_OK 572 * The decoder algorithm initialized. 573 * \retval #VPX_CODEC_MEM_ERROR 574 * Memory allocation failed. 575 */ 576 vpx_codec_err_t vpx_codec_enc_init_ver(vpx_codec_ctx_t *ctx, 577 vpx_codec_iface_t *iface, 578 vpx_codec_enc_cfg_t *cfg, 579 vpx_codec_flags_t flags, 580 int ver); 581 582 583 /*!\brief Convenience macro for vpx_codec_enc_init_ver() 584 * 585 * Ensures the ABI version parameter is properly set. 586 */ 587 #define vpx_codec_enc_init(ctx, iface, cfg, flags) \ 588 vpx_codec_enc_init_ver(ctx, iface, cfg, flags, VPX_ENCODER_ABI_VERSION) 589 590 591 /*!\brief Get a default configuration 592 * 593 * Initializes a encoder configuration structure with default values. Supports 594 * the notion of "usages" so that an algorithm may offer different default 595 * settings depending on the user's intended goal. This function \ref SHOULD 596 * be called by all applications to initialize the configuration structure 597 * before specializing the configuration with application specific values. 598 * 599 * \param[in] iface Pointer to the algorithm interface to use. 600 * \param[out] cfg Configuration buffer to populate 601 * \param[in] usage End usage. Set to 0 or use codec specific values. 602 * 603 * \retval #VPX_CODEC_OK 604 * The configuration was populated. 605 * \retval #VPX_CODEC_INCAPABLE 606 * Interface is not an encoder interface. 607 * \retval #VPX_CODEC_INVALID_PARAM 608 * A parameter was NULL, or the usage value was not recognized. 609 */ 610 vpx_codec_err_t vpx_codec_enc_config_default(vpx_codec_iface_t *iface, 611 vpx_codec_enc_cfg_t *cfg, 612 unsigned int usage); 613 614 615 /*!\brief Set or change configuration 616 * 617 * Reconfigures an encoder instance according to the given configuration. 618 * 619 * \param[in] ctx Pointer to this instance's context 620 * \param[in] cfg Configuration buffer to use 621 * 622 * \retval #VPX_CODEC_OK 623 * The configuration was populated. 624 * \retval #VPX_CODEC_INCAPABLE 625 * Interface is not an encoder interface. 626 * \retval #VPX_CODEC_INVALID_PARAM 627 * A parameter was NULL, or the usage value was not recognized. 628 */ 629 vpx_codec_err_t vpx_codec_enc_config_set(vpx_codec_ctx_t *ctx, 630 const vpx_codec_enc_cfg_t *cfg); 631 632 633 /*!\brief Get global stream headers 634 * 635 * Retrieves a stream level global header packet, if supported by the codec. 636 * 637 * \param[in] ctx Pointer to this instance's context 638 * 639 * \retval NULL 640 * Encoder does not support global header 641 * \retval Non-NULL 642 * Pointer to buffer containing global header packet 643 */ 644 vpx_fixed_buf_t *vpx_codec_get_global_headers(vpx_codec_ctx_t *ctx); 645 646 647 #define VPX_DL_REALTIME (1) /**< deadline parameter analogous to 648 * VPx REALTIME mode. */ 649 #define VPX_DL_GOOD_QUALITY (1000000) /**< deadline parameter analogous to 650 * VPx GOOD QUALITY mode. */ 651 #define VPX_DL_BEST_QUALITY (0) /**< deadline parameter analogous to 652 * VPx BEST QUALITY mode. */ 653 /*!\brief Encode a frame 654 * 655 * Encodes a video frame at the given "presentation time." The presentation 656 * time stamp (PTS) \ref MUST be strictly increasing. 657 * 658 * The encoder supports the notion of a soft real-time deadline. Given a 659 * non-zero value to the deadline parameter, the encoder will make a "best 660 * effort" guarantee to return before the given time slice expires. It is 661 * implicit that limiting the available time to encode will degrade the 662 * output quality. The encoder can be given an unlimited time to produce the 663 * best possible frame by specifying a deadline of '0'. This deadline 664 * supercedes the VPx notion of "best quality, good quality, realtime". 665 * Applications that wish to map these former settings to the new deadline 666 * based system can use the symbols #VPX_DL_REALTIME, #VPX_DL_GOOD_QUALITY, 667 * and #VPX_DL_BEST_QUALITY. 668 * 669 * When the last frame has been passed to the encoder, this function should 670 * continue to be called, with the img parameter set to NULL. This will 671 * signal the end-of-stream condition to the encoder and allow it to encode 672 * any held buffers. Encoding is complete when vpx_codec_encode() is called 673 * and vpx_codec_get_cx_data() returns no data. 674 * 675 * \param[in] ctx Pointer to this instance's context 676 * \param[in] img Image data to encode, NULL to flush. 677 * \param[in] pts Presentation time stamp, in timebase units. 678 * \param[in] duration Duration to show frame, in timebase units. 679 * \param[in] flags Flags to use for encoding this frame. 680 * \param[in] deadline Time to spend encoding, in microseconds. (0=infinite) 681 * 682 * \retval #VPX_CODEC_OK 683 * The configuration was populated. 684 * \retval #VPX_CODEC_INCAPABLE 685 * Interface is not an encoder interface. 686 * \retval #VPX_CODEC_INVALID_PARAM 687 * A parameter was NULL, the image format is unsupported, etc. 688 */ 689 vpx_codec_err_t vpx_codec_encode(vpx_codec_ctx_t *ctx, 690 const vpx_image_t *img, 691 vpx_codec_pts_t pts, 692 unsigned long duration, 693 vpx_enc_frame_flags_t flags, 694 unsigned long deadline); 695 696 697 /*!\brief Set compressed data output buffer 698 * 699 * Sets the buffer that the codec should output the compressed data 700 * into. This call effectively sets the buffer pointer returned in the 701 * next VPX_CODEC_CX_FRAME_PKT packet. Subsequent packets will be 702 * appended into this buffer. The buffer is preserved across frames, 703 * so applications must periodically call this function after flushing 704 * the accumulated compressed data to disk or to the network to reset 705 * the pointer to the buffer's head. 706 * 707 * `pad_before` bytes will be skipped before writing the compressed 708 * data, and `pad_after` bytes will be appended to the packet. The size 709 * of the packet will be the sum of the size of the actual compressed 710 * data, pad_before, and pad_after. The padding bytes will be preserved 711 * (not overwritten). 712 * 713 * Note that calling this function does not guarantee that the returned 714 * compressed data will be placed into the specified buffer. In the 715 * event that the encoded data will not fit into the buffer provided, 716 * the returned packet \ref MAY point to an internal buffer, as it would 717 * if this call were never used. In this event, the output packet will 718 * NOT have any padding, and the application must free space and copy it 719 * to the proper place. This is of particular note in configurations 720 * that may output multiple packets for a single encoded frame (e.g., lagged 721 * encoding) or if the application does not reset the buffer periodically. 722 * 723 * Applications may restore the default behavior of the codec providing 724 * the compressed data buffer by calling this function with a NULL 725 * buffer. 726 * 727 * Applications \ref MUSTNOT call this function during iteration of 728 * vpx_codec_get_cx_data(). 729 * 730 * \param[in] ctx Pointer to this instance's context 731 * \param[in] buf Buffer to store compressed data into 732 * \param[in] pad_before Bytes to skip before writing compressed data 733 * \param[in] pad_after Bytes to skip after writing compressed data 734 * 735 * \retval #VPX_CODEC_OK 736 * The buffer was set successfully. 737 * \retval #VPX_CODEC_INVALID_PARAM 738 * A parameter was NULL, the image format is unsupported, etc. 739 */ 740 vpx_codec_err_t vpx_codec_set_cx_data_buf(vpx_codec_ctx_t *ctx, 741 const vpx_fixed_buf_t *buf, 742 unsigned int pad_before, 743 unsigned int pad_after); 744 745 746 /*!\brief Encoded data iterator 747 * 748 * Iterates over a list of data packets to be passed from the encoder to the 749 * application. The different kinds of packets available are enumerated in 750 * #vpx_codec_cx_pkt_kind. 751 * 752 * #VPX_CODEC_CX_FRAME_PKT packets should be passed to the application's 753 * muxer. Multiple compressed frames may be in the list. 754 * #VPX_CODEC_STATS_PKT packets should be appended to a global buffer. 755 * 756 * The application \ref MUST silently ignore any packet kinds that it does 757 * not recognize or support. 758 * 759 * The data buffers returned from this function are only guaranteed to be 760 * valid until the application makes another call to any vpx_codec_* function. 761 * 762 * \param[in] ctx Pointer to this instance's context 763 * \param[in,out] iter Iterator storage, initialized to NULL 764 * 765 * \return Returns a pointer to an output data packet (compressed frame data, 766 * two-pass statistics, etc.) or NULL to signal end-of-list. 767 * 768 */ 769 const vpx_codec_cx_pkt_t *vpx_codec_get_cx_data(vpx_codec_ctx_t *ctx, 770 vpx_codec_iter_t *iter); 771 772 773 /*!\brief Get Preview Frame 774 * 775 * Returns an image that can be used as a preview. Shows the image as it would 776 * exist at the decompressor. The application \ref MUST NOT write into this 777 * image buffer. 778 * 779 * \param[in] ctx Pointer to this instance's context 780 * 781 * \return Returns a pointer to a preview image, or NULL if no image is 782 * available. 783 * 784 */ 785 const vpx_image_t *vpx_codec_get_preview_frame(vpx_codec_ctx_t *ctx); 786 787 788 /*!@} - end defgroup encoder*/ 789 790 #endif 791 #ifdef __cplusplus 792 } 793 #endif 794
