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      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 decoder Decoder Algorithm Interface
     13  * \ingroup codec
     14  * This abstraction allows applications using this decoder to easily support
     15  * multiple video formats with minimal code duplication. This section describes
     16  * the interface common to all decoders.
     17  * @{
     18  */
     19 
     20 /*!\file
     21  * \brief Describes the decoder algorithm interface to applications.
     22  *
     23  * This file describes the interface between an application and a
     24  * video decoder algorithm.
     25  *
     26  */
     27 #ifdef __cplusplus
     28 extern "C" {
     29 #endif
     30 
     31 #ifndef VPX_DECODER_H
     32 #define VPX_DECODER_H
     33 #include "vpx_codec.h"
     34 
     35     /*!\brief Current ABI version number
     36      *
     37      * \internal
     38      * If this file is altered in any way that changes the ABI, this value
     39      * must be bumped.  Examples include, but are not limited to, changing
     40      * types, removing or reassigning enums, adding/removing/rearranging
     41      * fields to structures
     42      */
     43 #define VPX_DECODER_ABI_VERSION (2 + VPX_CODEC_ABI_VERSION) /**<\hideinitializer*/
     44 
     45     /*! \brief Decoder capabilities bitfield
     46      *
     47      *  Each decoder advertises the capabilities it supports as part of its
     48      *  ::vpx_codec_iface_t interface structure. Capabilities are extra interfaces
     49      *  or functionality, and are not required to be supported by a decoder.
     50      *
     51      *  The available flags are specified by VPX_CODEC_CAP_* defines.
     52      */
     53 #define VPX_CODEC_CAP_PUT_SLICE  0x10000 /**< Will issue put_slice callbacks */
     54 #define VPX_CODEC_CAP_PUT_FRAME  0x20000 /**< Will issue put_frame callbacks */
     55 #define VPX_CODEC_CAP_POSTPROC   0x40000 /**< Can postprocess decoded frame */
     56 
     57     /*! \brief Initialization-time Feature Enabling
     58      *
     59      *  Certain codec features must be known at initialization time, to allow for
     60      *  proper memory allocation.
     61      *
     62      *  The available flags are specified by VPX_CODEC_USE_* defines.
     63      */
     64 #define VPX_CODEC_USE_POSTPROC   0x10000 /**< Postprocess decoded frame */
     65 
     66     /*!\brief Stream properties
     67      *
     68      * This structure is used to query or set properties of the decoded
     69      * stream. Algorithms may extend this structure with data specific
     70      * to their bitstream by setting the sz member appropriately.
     71      */
     72     typedef struct vpx_codec_stream_info
     73     {
     74         unsigned int sz;     /**< Size of this structure */
     75         unsigned int w;      /**< Width (or 0 for unknown/default) */
     76         unsigned int h;      /**< Height (or 0 for unknown/default) */
     77         unsigned int is_kf;  /**< Current frame is a keyframe */
     78     } vpx_codec_stream_info_t;
     79 
     80     /* REQUIRED FUNCTIONS
     81      *
     82      * The following functions are required to be implemented for all decoders.
     83      * They represent the base case functionality expected of all decoders.
     84      */
     85 
     86 
     87     /*!\brief Initialization Configurations
     88      *
     89      * This structure is used to pass init time configuration options to the
     90      * decoder.
     91      */
     92     typedef struct vpx_codec_dec_cfg
     93     {
     94         unsigned int threads; /**< Maximum number of threads to use, default 1 */
     95         unsigned int w;      /**< Width */
     96         unsigned int h;      /**< Height */
     97     } vpx_codec_dec_cfg_t; /**< alias for struct vpx_codec_dec_cfg */
     98 
     99 
    100     /*!\brief Initialize a decoder instance
    101      *
    102      * Initializes a decoder context using the given interface. Applications
    103      * should call the vpx_codec_dec_init convenience macro instead of this
    104      * function directly, to ensure that the ABI version number parameter
    105      * is properly initialized.
    106      *
    107      * In XMA mode (activated by setting VPX_CODEC_USE_XMA in the flags
    108      * parameter), the storage pointed to by the cfg parameter must be
    109      * kept readable and stable until all memory maps have been set.
    110      *
    111      * \param[in]    ctx     Pointer to this instance's context.
    112      * \param[in]    iface   Pointer to the algorithm interface to use.
    113      * \param[in]    cfg     Configuration to use, if known. May be NULL.
    114      * \param[in]    flags   Bitfield of VPX_CODEC_USE_* flags
    115      * \param[in]    ver     ABI version number. Must be set to
    116      *                       VPX_DECODER_ABI_VERSION
    117      * \retval #VPX_CODEC_OK
    118      *     The decoder algorithm initialized.
    119      * \retval #VPX_CODEC_MEM_ERROR
    120      *     Memory allocation failed.
    121      */
    122     vpx_codec_err_t vpx_codec_dec_init_ver(vpx_codec_ctx_t      *ctx,
    123                                            vpx_codec_iface_t    *iface,
    124                                            vpx_codec_dec_cfg_t  *cfg,
    125                                            vpx_codec_flags_t     flags,
    126                                            int                   ver);
    127 
    128     /*!\brief Convenience macro for vpx_codec_dec_init_ver()
    129      *
    130      * Ensures the ABI version parameter is properly set.
    131      */
    132 #define vpx_codec_dec_init(ctx, iface, cfg, flags) \
    133     vpx_codec_dec_init_ver(ctx, iface, cfg, flags, VPX_DECODER_ABI_VERSION)
    134 
    135 
    136     /*!\brief Parse stream info from a buffer
    137      *
    138      * Performs high level parsing of the bitstream. Construction of a decoder
    139      * context is not necessary. Can be used to determine if the bitstream is
    140      * of the proper format, and to extract information from the stream.
    141      *
    142      * \param[in]      iface   Pointer to the algorithm interface
    143      * \param[in]      data    Pointer to a block of data to parse
    144      * \param[in]      data_sz Size of the data buffer
    145      * \param[in,out]  si      Pointer to stream info to update. The size member
    146      *                         \ref MUST be properly initialized, but \ref MAY be
    147      *                         clobbered by the algorithm. This parameter \ref MAY
    148      *                         be NULL.
    149      *
    150      * \retval #VPX_CODEC_OK
    151      *     Bitstream is parsable and stream information updated
    152      */
    153     vpx_codec_err_t vpx_codec_peek_stream_info(vpx_codec_iface_t       *iface,
    154             const uint8_t           *data,
    155             unsigned int             data_sz,
    156             vpx_codec_stream_info_t *si);
    157 
    158 
    159     /*!\brief Return information about the current stream.
    160      *
    161      * Returns information about the stream that has been parsed during decoding.
    162      *
    163      * \param[in]      ctx     Pointer to this instance's context
    164      * \param[in,out]  si      Pointer to stream info to update. The size member
    165      *                         \ref MUST be properly initialized, but \ref MAY be
    166      *                         clobbered by the algorithm. This parameter \ref MAY
    167      *                         be NULL.
    168      *
    169      * \retval #VPX_CODEC_OK
    170      *     Bitstream is parsable and stream information updated
    171      */
    172     vpx_codec_err_t vpx_codec_get_stream_info(vpx_codec_ctx_t         *ctx,
    173             vpx_codec_stream_info_t *si);
    174 
    175 
    176     /*!\brief Decode data
    177      *
    178      * Processes a buffer of coded data. If the processing results in a new
    179      * decoded frame becoming available, PUT_SLICE and PUT_FRAME events may be
    180      * generated, as appropriate. Encoded data \ref MUST be passed in DTS (decode
    181      * time stamp) order. Frames produced will always be in PTS (presentation
    182      * time stamp) order.
    183      *
    184      * \param[in] ctx          Pointer to this instance's context
    185      * \param[in] data         Pointer to this block of new coded data. If
    186      *                         NULL, a VPX_CODEC_CB_PUT_FRAME event is posted
    187      *                         for the previously decoded frame.
    188      * \param[in] data_sz      Size of the coded data, in bytes.
    189      * \param[in] user_priv    Application specific data to associate with
    190      *                         this frame.
    191      * \param[in] deadline     Soft deadline the decoder should attempt to meet,
    192      *                         in us. Set to zero for unlimited.
    193      *
    194      * \return Returns #VPX_CODEC_OK if the coded data was processed completely
    195      *         and future pictures can be decoded without error. Otherwise,
    196      *         see the descriptions of the other error codes in ::vpx_codec_err_t
    197      *         for recoverability capabilities.
    198      */
    199     vpx_codec_err_t vpx_codec_decode(vpx_codec_ctx_t    *ctx,
    200                                      const uint8_t        *data,
    201                                      unsigned int            data_sz,
    202                                      void               *user_priv,
    203                                      long                deadline);
    204 
    205 
    206     /*!\brief Decoded frames iterator
    207      *
    208      * Iterates over a list of the frames available for display. The iterator
    209      * storage should be initialized to NULL to start the iteration. Iteration is
    210      * complete when this function returns NULL.
    211      *
    212      * The list of available frames becomes valid upon completion of the
    213      * vpx_codec_decode call, and remains valid until the next call to vpx_codec_decode.
    214      *
    215      * \param[in]     ctx      Pointer to this instance's context
    216      * \param[in,out] iter     Iterator storage, initialized to NULL
    217      *
    218      * \return Returns a pointer to an image, if one is ready for display. Frames
    219      *         produced will always be in PTS (presentation time stamp) order.
    220      */
    221     vpx_image_t *vpx_codec_get_frame(vpx_codec_ctx_t  *ctx,
    222                                      vpx_codec_iter_t *iter);
    223 
    224 
    225     /*!\defgroup cap_put_frame Frame-Based Decoding Functions
    226      *
    227      * The following functions are required to be implemented for all decoders
    228      * that advertise the VPX_CODEC_CAP_PUT_FRAME capability. Calling these functions
    229      * for codecs that don't advertise this capability will result in an error
    230      * code being returned, usually VPX_CODEC_ERROR
    231      * @{
    232      */
    233 
    234     /*!\brief put frame callback prototype
    235      *
    236      * This callback is invoked by the decoder to notify the application of
    237      * the availability of decoded image data.
    238      */
    239     typedef void (*vpx_codec_put_frame_cb_fn_t)(void        *user_priv,
    240             const vpx_image_t *img);
    241 
    242 
    243     /*!\brief Register for notification of frame completion.
    244      *
    245      * Registers a given function to be called when a decoded frame is
    246      * available.
    247      *
    248      * \param[in] ctx          Pointer to this instance's context
    249      * \param[in] cb           Pointer to the callback function
    250      * \param[in] user_priv    User's private data
    251      *
    252      * \retval #VPX_CODEC_OK
    253      *     Callback successfully registered.
    254      * \retval #VPX_CODEC_ERROR
    255      *     Decoder context not initialized, or algorithm not capable of
    256      *     posting slice completion.
    257      */
    258     vpx_codec_err_t vpx_codec_register_put_frame_cb(vpx_codec_ctx_t             *ctx,
    259             vpx_codec_put_frame_cb_fn_t  cb,
    260             void                        *user_priv);
    261 
    262 
    263     /*!@} - end defgroup cap_put_frame */
    264 
    265     /*!\defgroup cap_put_slice Slice-Based Decoding Functions
    266      *
    267      * The following functions are required to be implemented for all decoders
    268      * that advertise the VPX_CODEC_CAP_PUT_SLICE capability. Calling these functions
    269      * for codecs that don't advertise this capability will result in an error
    270      * code being returned, usually VPX_CODEC_ERROR
    271      * @{
    272      */
    273 
    274     /*!\brief put slice callback prototype
    275      *
    276      * This callback is invoked by the decoder to notify the application of
    277      * the availability of partially decoded image data. The
    278      */
    279     typedef void (*vpx_codec_put_slice_cb_fn_t)(void         *user_priv,
    280             const vpx_image_t      *img,
    281             const vpx_image_rect_t *valid,
    282             const vpx_image_rect_t *update);
    283 
    284 
    285     /*!\brief Register for notification of slice completion.
    286      *
    287      * Registers a given function to be called when a decoded slice is
    288      * available.
    289      *
    290      * \param[in] ctx          Pointer to this instance's context
    291      * \param[in] cb           Pointer to the callback function
    292      * \param[in] user_priv    User's private data
    293      *
    294      * \retval #VPX_CODEC_OK
    295      *     Callback successfully registered.
    296      * \retval #VPX_CODEC_ERROR
    297      *     Decoder context not initialized, or algorithm not capable of
    298      *     posting slice completion.
    299      */
    300     vpx_codec_err_t vpx_codec_register_put_slice_cb(vpx_codec_ctx_t             *ctx,
    301             vpx_codec_put_slice_cb_fn_t  cb,
    302             void                        *user_priv);
    303 
    304 
    305     /*!@} - end defgroup cap_put_slice*/
    306 
    307     /*!@} - end defgroup decoder*/
    308 
    309 #endif
    310 
    311 #ifdef __cplusplus
    312 }
    313 #endif
    314 
    315 #if !defined(VPX_CODEC_DISABLE_COMPAT) || !VPX_CODEC_DISABLE_COMPAT
    316 #include "vpx_decoder_compat.h"
    317 #endif
    318