/*
* Copyright (c) 2010 The WebM project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
/*!\defgroup encoder Encoder Algorithm Interface
* \ingroup codec
* This abstraction allows applications using this encoder to easily support
* multiple video formats with minimal code duplication. This section describes
* the interface common to all encoders.
* @{
*/
/*!\file vpx_encoder.h
* \brief Describes the encoder algorithm interface to applications.
*
* This file describes the interface between an application and a
* video encoder algorithm.
*
*/
#ifdef __cplusplus
extern "C" {
#endif
#ifndef VPX_ENCODER_H
#define VPX_ENCODER_H
#include "vpx_codec.h"
/*!\brief Current ABI version number
*
* \internal
* If this file is altered in any way that changes the ABI, this value
* must be bumped. Examples include, but are not limited to, changing
* types, removing or reassigning enums, adding/removing/rearranging
* fields to structures
*/
#define VPX_ENCODER_ABI_VERSION (2 + VPX_CODEC_ABI_VERSION) /**<\hideinitializer*/
/*! \brief Encoder capabilities bitfield
*
* Each encoder advertises the capabilities it supports as part of its
* ::vpx_codec_iface_t interface structure. Capabilities are extra
* interfaces or functionality, and are not required to be supported
* by an encoder.
*
* The available flags are specifiedby VPX_CODEC_CAP_* defines.
*/
#define VPX_CODEC_CAP_PSNR 0x10000 /**< Can issue PSNR packets */
/*! \brief Initialization-time Feature Enabling
*
* Certain codec features must be known at initialization time, to allow
* for proper memory allocation.
*
* The available flags are specified by VPX_CODEC_USE_* defines.
*/
#define VPX_CODEC_USE_PSNR 0x10000 /**< Calculate PSNR on each frame */
/*!\brief Generic fixed size buffer structure
*
* This structure is able to hold a reference to any fixed size buffer.
*/
typedef struct vpx_fixed_buf
{
void *buf; /**< Pointer to the data */
size_t sz; /**< Length of the buffer, in chars */
} vpx_fixed_buf_t; /**< alias for struct vpx_fixed_buf */
/*!\brief Time Stamp Type
*
* An integer, which when multiplied by the stream's time base, provides
* the absolute time of a sample.
*/
typedef int64_t vpx_codec_pts_t;
/*!\brief Compressed Frame Flags
*
* This type represents a bitfield containing information about a compressed
* frame that may be useful to an application. The most significant 16 bits
* can be used by an algorithm to provide additional detail, for example to
* support frame types that are codec specific (MPEG-1 D-frames for example)
*/
typedef uint32_t vpx_codec_frame_flags_t;
#define VPX_FRAME_IS_KEY 0x1 /**< frame is the start of a GOP */
#define VPX_FRAME_IS_DROPPABLE 0x2 /**< frame can be dropped without affecting
the stream (no future frame depends on
this one) */
#define VPX_FRAME_IS_INVISIBLE 0x4 /**< frame should be decoded but will not
be shown */
/*!\brief Encoder output packet variants
*
* This enumeration lists the different kinds of data packets that can be
* returned by calls to vpx_codec_get_cx_data(). Algorithms \ref MAY
* extend this list to provide additional functionality.
*/
enum vpx_codec_cx_pkt_kind
{
VPX_CODEC_CX_FRAME_PKT, /**< Compressed video frame */
VPX_CODEC_STATS_PKT, /**< Two-pass statistics for this frame */
VPX_CODEC_PSNR_PKT, /**< PSNR statistics for this frame */
VPX_CODEC_CUSTOM_PKT = 256 /**< Algorithm extensions */
};
/*!\brief Encoder output packet
*
* This structure contains the different kinds of output data the encoder
* may produce while compressing a frame.
*/
typedef struct vpx_codec_cx_pkt
{
enum vpx_codec_cx_pkt_kind kind; /**< packet variant */
union
{
struct
{
void *buf; /**< compressed data buffer */
size_t sz; /**< length of compressed data */
vpx_codec_pts_t pts; /**< time stamp to show frame
(in timebase units) */
unsigned long duration; /**< duration to show frame
(in timebase units) */
vpx_codec_frame_flags_t flags; /**< flags for this frame */
} frame; /**< data for compressed frame packet */
struct vpx_fixed_buf twopass_stats; /**< data for two-pass packet */
struct vpx_psnr_pkt
{
unsigned int samples[4]; /**< Number of samples, total/y/u/v */
uint64_t sse[4]; /**< sum squared error, total/y/u/v */
double psnr[4]; /**< PSNR, total/y/u/v */
} psnr; /**< data for PSNR packet */
struct vpx_fixed_buf raw; /**< data for arbitrary packets */
/* This packet size is fixed to allow codecs to extend this
* interface without having to manage storage for raw packets,
* ie if it's smaller than 128 bytes, you can store in the
* packet list directly.
*/
char pad[128 - sizeof(enum vpx_codec_cx_pkt_kind)]; /**< fixed sz */
} data; /**< packet data */
} vpx_codec_cx_pkt_t; /**< alias for struct vpx_codec_cx_pkt */
/*!\brief Rational Number
*
* This structure holds a fractional value.
*/
typedef struct vpx_rational
{
int num; /**< fraction numerator */
int den; /**< fraction denominator */
} vpx_rational_t; /**< alias for struct vpx_rational */
/*!\brief Multi-pass Encoding Pass */
enum vpx_enc_pass
{
VPX_RC_ONE_PASS, /**< Single pass mode */
VPX_RC_FIRST_PASS, /**< First pass of multi-pass mode */
VPX_RC_LAST_PASS /**< Final pass of multi-pass mode */
};
/*!\brief Rate control mode */
enum vpx_rc_mode
{
VPX_VBR, /**< Variable Bit Rate (VBR) mode */
VPX_CBR /**< Constant Bit Rate (CBR) mode */
};
/*!\brief Keyframe placement mode.
*
* This enumeration determines whether keyframes are placed automatically by
* the encoder or whether this behavior is disabled. Older releases of this
* SDK were implemented such that VPX_KF_FIXED meant keyframes were disabled.
* This name is confusing for this behavior, so the new symbols to be used
* are VPX_KF_AUTO and VPX_KF_DISABLED.
*/
enum vpx_kf_mode
{
VPX_KF_FIXED, /**< deprecated, implies VPX_KF_DISABLED */
VPX_KF_AUTO, /**< Encoder determines optimal placement automatically */
VPX_KF_DISABLED = 0 /**< Encoder does not place keyframes. */
};
/*!\brief Encoded Frame Flags
*
* This type indicates a bitfield to be passed to vpx_codec_encode(), defining
* per-frame boolean values. By convention, bits common to all codecs will be
* named VPX_EFLAG_*, and bits specific to an algorithm will be named
* /algo/_eflag_*. The lower order 16 bits are reserved for common use.
*/
typedef long vpx_enc_frame_flags_t;
#define VPX_EFLAG_FORCE_KF (1<<0) /**< Force this frame to be a keyframe */
/*!\brief Encoder configuration structure
*
* This structure contains the encoder settings that have common representations
* across all codecs. This doesn't imply that all codecs support all features,
* however.
*/
typedef struct vpx_codec_enc_cfg
{
/*
* generic settings (g)
*/
/*!\brief Algorithm specific "usage" value
*
* Algorithms may define multiple values for usage, which may convey the
* intent of how the application intends to use the stream. If this value
* is non-zero, consult the documentation for the codec to determine its
* meaning.
*/
unsigned int g_usage;
/*!\brief Maximum number of threads to use
*
* For multi-threaded implementations, use no more than this number of
* threads. The codec may use fewer threads than allowed. The value
* 0 is equivalent to the value 1.
*/
unsigned int g_threads;
/*!\brief Bitstream profile to use
*
* Some codecs support a notion of multiple bitstream profiles. Typically
* this maps to a set of features that are turned on or off. Often the
* profile to use is determined by the features of the intended decoder.
* Consult the documentation for the codec to determine the valid values
* for this parameter, or set to zero for a sane default.
*/
unsigned int g_profile; /**< profile of bitstream to use */
/*!\brief Width of the frame
*
* This value identifies the presentation resolution of the frame,
* in pixels. Note that the frames passed as input to the encoder must
* have this resolution. Frames will be presented by the decoder in this
* resolution, independent of any spatial resampling the encoder may do.
*/
unsigned int g_w;
/*!\brief Height of the frame
*
* This value identifies the presentation resolution of the frame,
* in pixels. Note that the frames passed as input to the encoder must
* have this resolution. Frames will be presented by the decoder in this
* resolution, independent of any spatial resampling the encoder may do.
*/
unsigned int g_h;
/*!\brief Stream timebase units
*
* Indicates the smallest interval of time, in seconds, used by the stream.
* For fixed frame rate material, or variable frame rate material where
* frames are timed at a multiple of a given clock (ex: video capture),
* the \ref RECOMMENDED method is to set the timebase to the reciprocal
* of the frame rate (ex: 1001/30000 for 29.970 Hz NTSC). This allows the
* pts to correspond to the frame number, which can be handy. For
* re-encoding video from containers with absolute time timestamps, the
* \ref RECOMMENDED method is to set the timebase to that of the parent
* container or multimedia framework (ex: 1/1000 for ms, as in FLV).
*/
struct vpx_rational g_timebase;
/*!\brief Enable error resilient mode.
*
* Error resilient mode indicates to the encoder that it should take
* measures appropriate for streaming over lossy or noisy links, if
* possible. Set to 1 to enable this feature, 0 to disable it.
*/
unsigned int g_error_resilient;
/*!\brief Multi-pass Encoding Mode
*
* This value should be set to the current phase for multi-pass encoding.
* For single pass, set to #VPX_RC_ONE_PASS.
*/
enum vpx_enc_pass g_pass;
/*!\brief Allow lagged encoding
*
* If set, this value allows the encoder to consume a number of input
* frames before producing output frames. This allows the encoder to
* base decisions for the current frame on future frames. This does
* increase the latency of the encoding pipeline, so it is not appropriate
* in all situations (ex: realtime encoding).
*
* Note that this is a maximum value -- the encoder may produce frames
* sooner than the given limit. Set this value to 0 to disable this
* feature.
*/
unsigned int g_lag_in_frames;
/*
* rate control settings (rc)
*/
/*!\brief Temporal resampling configuration, if supported by the codec.
*
* Temporal resampling allows the codec to "drop" frames as a strategy to
* meet its target data rate. This can cause temporal discontinuities in
* the encoded video, which may appear as stuttering during playback. This
* trade-off is often acceptable, but for many applications is not. It can
* be disabled in these cases.
*
* Note that not all codecs support this feature. All vpx VPx codecs do.
* For other codecs, consult the documentation for that algorithm.
*
* This threshold is described as a percentage of the target data buffer.
* When the data buffer falls below this percentage of fullness, a
* dropped frame is indicated. Set the threshold to zero (0) to disable
* this feature.
*/
unsigned int rc_dropframe_thresh;
/*!\brief Enable/disable spatial resampling, if supported by the codec.
*
* Spatial resampling allows the codec to compress a lower resolution
* version of the frame, which is then upscaled by the encoder to the
* correct presentation resolution. This increases visual quality at
* low data rates, at the expense of CPU time on the encoder/decoder.
*/
unsigned int rc_resize_allowed;
/*!\brief Spatial resampling up watermark.
*
* This threshold is described as a percentage of the target data buffer.
* When the data buffer rises above this percentage of fullness, the
* encoder will step up to a higher resolution version of the frame.
*/
unsigned int rc_resize_up_thresh;
/*!\brief Spatial resampling down watermark.
*
* This threshold is described as a percentage of the target data buffer.
* When the data buffer falls below this percentage of fullness, the
* encoder will step down to a lower resolution version of the frame.
*/
unsigned int rc_resize_down_thresh;
/*!\brief Rate control algorithm to use.
*
* Indicates whether the end usage of this stream is to be streamed over
* a bandwidth constrained link, indicating that Constant Bit Rate (CBR)
* mode should be used, or whether it will be played back on a high
* bandwidth link, as from a local disk, where higher variations in
* bitrate are acceptable.
*/
enum vpx_rc_mode rc_end_usage;
/*!\brief Two-pass stats buffer.
*
* A buffer containing all of the stats packets produced in the first
* pass, concatenated.
*/
struct vpx_fixed_buf rc_twopass_stats_in;
/*!\brief Target data rate
*
* Target bandwidth to use for this stream, in kilobits per second.
*/
unsigned int rc_target_bitrate;
/*
* quantizer settings
*/
/*!\brief Minimum (Best Quality) Quantizer
*
* The quantizer is the most direct control over the quality of the
* encoded image. The range of valid values for the quantizer is codec
* specific. Consult the documentation for the codec to determine the
* values to use. To determine the range programmatically, call
* vpx_codec_enc_config_default() with a usage value of 0.
*/
unsigned int rc_min_quantizer;
/*!\brief Maximum (Worst Quality) Quantizer
*
* The quantizer is the most direct control over the quality of the
* encoded image. The range of valid values for the quantizer is codec
* specific. Consult the documentation for the codec to determine the
* values to use. To determine the range programmatically, call
* vpx_codec_enc_config_default() with a usage value of 0.
*/
unsigned int rc_max_quantizer;
/*
* bitrate tolerance
*/
/*!\brief Rate control undershoot tolerance
*
* This value, expressed as a percentage of the target bitrate, describes
* the target bitrate for easier frames, allowing bits to be saved for
* harder frames. Set to zero to use the codec default.
*/
unsigned int rc_undershoot_pct;
/*!\brief Rate control overshoot tolerance
*
* This value, expressed as a percentage of the target bitrate, describes
* the maximum allowed bitrate for a given frame. Set to zero to use the
* codec default.
*/
unsigned int rc_overshoot_pct;
/*
* decoder buffer model parameters
*/
/*!\brief Decoder Buffer Size
*
* This value indicates the amount of data that may be buffered by the
* decoding application. Note that this value is expressed in units of
* time (milliseconds). For example, a value of 5000 indicates that the
* client will buffer (at least) 5000ms worth of encoded data. Use the
* target bitrate (#rc_target_bitrate) to convert to bits/bytes, if
* necessary.
*/
unsigned int rc_buf_sz;
/*!\brief Decoder Buffer Initial Size
*
* This value indicates the amount of data that will be buffered by the
* decoding application prior to beginning playback. This value is
* expressed in units of time (milliseconds). Use the target bitrate
* (#rc_target_bitrate) to convert to bits/bytes, if necessary.
*/
unsigned int rc_buf_initial_sz;
/*!\brief Decoder Buffer Optimal Size
*
* This value indicates the amount of data that the encoder should try
* to maintain in the decoder's buffer. This value is expressed in units
* of time (milliseconds). Use the target bitrate (#rc_target_bitrate)
* to convert to bits/bytes, if necessary.
*/
unsigned int rc_buf_optimal_sz;
/*
* 2 pass rate control parameters
*/
/*!\brief Two-pass mode CBR/VBR bias
*
* Bias, expressed on a scale of 0 to 100, for determining target size
* for the current frame. The value 0 indicates the optimal CBR mode
* value should be used. The value 100 indicates the optimal VBR mode
* value should be used. Values in between indicate which way the
* encoder should "lean."
*/
unsigned int rc_2pass_vbr_bias_pct; /**< RC mode bias between CBR and VBR(0-100: 0->CBR, 100->VBR) */
/*!\brief Two-pass mode per-GOP minimum bitrate
*
* This value, expressed as a percentage of the target bitrate, indicates
* the minimum bitrate to be used for a single GOP (aka "section")
*/
unsigned int rc_2pass_vbr_minsection_pct;
/*!\brief Two-pass mode per-GOP maximum bitrate
*
* This value, expressed as a percentage of the target bitrate, indicates
* the maximum bitrate to be used for a single GOP (aka "section")
*/
unsigned int rc_2pass_vbr_maxsection_pct;
/*
* keyframing settings (kf)
*/
/*!\brief Keyframe placement mode
*
* This value indicates whether the encoder should place keyframes at a
* fixed interval, or determine the optimal placement automatically
* (as governed by the #kf_min_dist and #kf_max_dist parameters)
*/
enum vpx_kf_mode kf_mode;
/*!\brief Keyframe minimum interval
*
* This value, expressed as a number of frames, prevents the encoder from
* placing a keyframe nearer than kf_min_dist to the previous keyframe. At
* least kf_min_dist frames non-keyframes will be coded before the next
* keyframe. Set kf_min_dist equal to kf_max_dist for a fixed interval.
*/
unsigned int kf_min_dist;
/*!\brief Keyframe maximum interval
*
* This value, expressed as a number of frames, forces the encoder to code
* a keyframe if one has not been coded in the last kf_max_dist frames.
* A value of 0 implies all frames will be keyframes. Set kf_min_dist
* equal to kf_max_dist for a fixed interval.
*/
unsigned int kf_max_dist;
} vpx_codec_enc_cfg_t; /**< alias for struct vpx_codec_enc_cfg */
/*!\brief Initialize an encoder instance
*
* Initializes a encoder context using the given interface. Applications
* should call the vpx_codec_enc_init convenience macro instead of this
* function directly, to ensure that the ABI version number parameter
* is properly initialized.
*
* In XMA mode (activated by setting VPX_CODEC_USE_XMA in the flags
* parameter), the storage pointed to by the cfg parameter must be
* kept readable and stable until all memory maps have been set.
*
* \param[in] ctx Pointer to this instance's context.
* \param[in] iface Pointer to the algorithm interface to use.
* \param[in] cfg Configuration to use, if known. May be NULL.
* \param[in] flags Bitfield of VPX_CODEC_USE_* flags
* \param[in] ver ABI version number. Must be set to
* VPX_ENCODER_ABI_VERSION
* \retval #VPX_CODEC_OK
* The decoder algorithm initialized.
* \retval #VPX_CODEC_MEM_ERROR
* Memory allocation failed.
*/
vpx_codec_err_t vpx_codec_enc_init_ver(vpx_codec_ctx_t *ctx,
vpx_codec_iface_t *iface,
vpx_codec_enc_cfg_t *cfg,
vpx_codec_flags_t flags,
int ver);
/*!\brief Convenience macro for vpx_codec_enc_init_ver()
*
* Ensures the ABI version parameter is properly set.
*/
#define vpx_codec_enc_init(ctx, iface, cfg, flags) \
vpx_codec_enc_init_ver(ctx, iface, cfg, flags, VPX_ENCODER_ABI_VERSION)
/*!\brief Get a default configuration
*
* Initializes a encoder configuration structure with default values. Supports
* the notion of "usages" so that an algorithm may offer different default
* settings depending on the user's intended goal. This function \ref SHOULD
* be called by all applications to initialize the configuration structure
* before specializing the configuration with application specific values.
*
* \param[in] iface Pointer to the algorithm interface to use.
* \param[out] cfg Configuration buffer to populate
* \param[in] usage End usage. Set to 0 or use codec specific values.
*
* \retval #VPX_CODEC_OK
* The configuration was populated.
* \retval #VPX_CODEC_INCAPABLE
* Interface is not an encoder interface.
* \retval #VPX_CODEC_INVALID_PARAM
* A parameter was NULL, or the usage value was not recognized.
*/
vpx_codec_err_t vpx_codec_enc_config_default(vpx_codec_iface_t *iface,
vpx_codec_enc_cfg_t *cfg,
unsigned int usage);
/*!\brief Set or change configuration
*
* Reconfigures an encoder instance according to the given configuration.
*
* \param[in] ctx Pointer to this instance's context
* \param[in] cfg Configuration buffer to use
*
* \retval #VPX_CODEC_OK
* The configuration was populated.
* \retval #VPX_CODEC_INCAPABLE
* Interface is not an encoder interface.
* \retval #VPX_CODEC_INVALID_PARAM
* A parameter was NULL, or the usage value was not recognized.
*/
vpx_codec_err_t vpx_codec_enc_config_set(vpx_codec_ctx_t *ctx,
const vpx_codec_enc_cfg_t *cfg);
/*!\brief Get global stream headers
*
* Retrieves a stream level global header packet, if supported by the codec.
*
* \param[in] ctx Pointer to this instance's context
*
* \retval NULL
* Encoder does not support global header
* \retval Non-NULL
* Pointer to buffer containing global header packet
*/
vpx_fixed_buf_t *vpx_codec_get_global_headers(vpx_codec_ctx_t *ctx);
#define VPX_DL_REALTIME (1) /**< deadline parameter analogous to
* VPx REALTIME mode. */
#define VPX_DL_GOOD_QUALITY (1000000) /**< deadline parameter analogous to
* VPx GOOD QUALITY mode. */
#define VPX_DL_BEST_QUALITY (0) /**< deadline parameter analogous to
* VPx BEST QUALITY mode. */
/*!\brief Encode a frame
*
* Encodes a video frame at the given "presentation time." The presentation
* time stamp (PTS) \ref MUST be strictly increasing.
*
* The encoder supports the notion of a soft real-time deadline. Given a
* non-zero value to the deadline parameter, the encoder will make a "best
* effort" guarantee to return before the given time slice expires. It is
* implicit that limiting the available time to encode will degrade the
* output quality. The encoder can be given an unlimited time to produce the
* best possible frame by specifying a deadline of '0'. This deadline
* supercedes the VPx notion of "best quality, good quality, realtime".
* Applications that wish to map these former settings to the new deadline
* based system can use the symbols #VPX_DL_REALTIME, #VPX_DL_GOOD_QUALITY,
* and #VPX_DL_BEST_QUALITY.
*
* When the last frame has been passed to the encoder, this function should
* continue to be called, with the img parameter set to NULL. This will
* signal the end-of-stream condition to the encoder and allow it to encode
* any held buffers. Encoding is complete when vpx_codec_encode() is called
* and vpx_codec_get_cx_data() returns no data.
*
* \param[in] ctx Pointer to this instance's context
* \param[in] img Image data to encode, NULL to flush.
* \param[in] pts Presentation time stamp, in timebase units.
* \param[in] duration Duration to show frame, in timebase units.
* \param[in] flags Flags to use for encoding this frame.
* \param[in] deadline Time to spend encoding, in microseconds. (0=infinite)
*
* \retval #VPX_CODEC_OK
* The configuration was populated.
* \retval #VPX_CODEC_INCAPABLE
* Interface is not an encoder interface.
* \retval #VPX_CODEC_INVALID_PARAM
* A parameter was NULL, the image format is unsupported, etc.
*/
vpx_codec_err_t vpx_codec_encode(vpx_codec_ctx_t *ctx,
const vpx_image_t *img,
vpx_codec_pts_t pts,
unsigned long duration,
vpx_enc_frame_flags_t flags,
unsigned long deadline);
/*!\brief Set compressed data output buffer
*
* Sets the buffer that the codec should output the compressed data
* into. This call effectively sets the buffer pointer returned in the
* next VPX_CODEC_CX_FRAME_PKT packet. Subsequent packets will be
* appended into this buffer. The buffer is preserved across frames,
* so applications must periodically call this function after flushing
* the accumulated compressed data to disk or to the network to reset
* the pointer to the buffer's head.
*
* `pad_before` bytes will be skipped before writing the compressed
* data, and `pad_after` bytes will be appended to the packet. The size
* of the packet will be the sum of the size of the actual compressed
* data, pad_before, and pad_after. The padding bytes will be preserved
* (not overwritten).
*
* Note that calling this function does not guarantee that the returned
* compressed data will be placed into the specified buffer. In the
* event that the encoded data will not fit into the buffer provided,
* the returned packet \ref MAY point to an internal buffer, as it would
* if this call were never used. In this event, the output packet will
* NOT have any padding, and the application must free space and copy it
* to the proper place. This is of particular note in configurations
* that may output multiple packets for a single encoded frame (e.g., lagged
* encoding) or if the application does not reset the buffer periodically.
*
* Applications may restore the default behavior of the codec providing
* the compressed data buffer by calling this function with a NULL
* buffer.
*
* Applications \ref MUSTNOT call this function during iteration of
* vpx_codec_get_cx_data().
*
* \param[in] ctx Pointer to this instance's context
* \param[in] buf Buffer to store compressed data into
* \param[in] pad_before Bytes to skip before writing compressed data
* \param[in] pad_after Bytes to skip after writing compressed data
*
* \retval #VPX_CODEC_OK
* The buffer was set successfully.
* \retval #VPX_CODEC_INVALID_PARAM
* A parameter was NULL, the image format is unsupported, etc.
*/
vpx_codec_err_t vpx_codec_set_cx_data_buf(vpx_codec_ctx_t *ctx,
const vpx_fixed_buf_t *buf,
unsigned int pad_before,
unsigned int pad_after);
/*!\brief Encoded data iterator
*
* Iterates over a list of data packets to be passed from the encoder to the
* application. The different kinds of packets available are enumerated in
* #vpx_codec_cx_pkt_kind.
*
* #VPX_CODEC_CX_FRAME_PKT packets should be passed to the application's
* muxer. Multiple compressed frames may be in the list.
* #VPX_CODEC_STATS_PKT packets should be appended to a global buffer.
*
* The application \ref MUST silently ignore any packet kinds that it does
* not recognize or support.
*
* The data buffers returned from this function are only guaranteed to be
* valid until the application makes another call to any vpx_codec_* function.
*
* \param[in] ctx Pointer to this instance's context
* \param[in,out] iter Iterator storage, initialized to NULL
*
* \return Returns a pointer to an output data packet (compressed frame data,
* two-pass statistics, etc.) or NULL to signal end-of-list.
*
*/
const vpx_codec_cx_pkt_t *vpx_codec_get_cx_data(vpx_codec_ctx_t *ctx,
vpx_codec_iter_t *iter);
/*!\brief Get Preview Frame
*
* Returns an image that can be used as a preview. Shows the image as it would
* exist at the decompressor. The application \ref MUST NOT write into this
* image buffer.
*
* \param[in] ctx Pointer to this instance's context
*
* \return Returns a pointer to a preview image, or NULL if no image is
* available.
*
*/
const vpx_image_t *vpx_codec_get_preview_frame(vpx_codec_ctx_t *ctx);
/*!@} - end defgroup encoder*/
#endif
#ifdef __cplusplus
}
#endif