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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 #ifndef VPX_DECODER_H
     11 #define VPX_DECODER_H
     12 
     13 /*!\defgroup decoder Decoder Algorithm Interface
     14  * \ingroup codec
     15  * This abstraction allows applications using this decoder to easily support
     16  * multiple video formats with minimal code duplication. This section describes
     17  * the interface common to all decoders.
     18  * @{
     19  */
     20 
     21 /*!\file
     22  * \brief Describes the decoder algorithm interface to applications.
     23  *
     24  * This file describes the interface between an application and a
     25  * video decoder algorithm.
     26  *
     27  */
     28 #ifdef __cplusplus
     29 extern "C" {
     30 #endif
     31 
     32 #include "vpx_codec.h"
     33 
     34   /*!\brief Current ABI version number
     35    *
     36    * \internal
     37    * If this file is altered in any way that changes the ABI, this value
     38    * must be bumped.  Examples include, but are not limited to, changing
     39    * types, removing or reassigning enums, adding/removing/rearranging
     40    * fields to structures
     41    */
     42 #define VPX_DECODER_ABI_VERSION (2 + VPX_CODEC_ABI_VERSION) /**<\hideinitializer*/
     43 
     44   /*! \brief Decoder capabilities bitfield
     45    *
     46    *  Each decoder advertises the capabilities it supports as part of its
     47    *  ::vpx_codec_iface_t interface structure. Capabilities are extra interfaces
     48    *  or functionality, and are not required to be supported by a decoder.
     49    *
     50    *  The available flags are specified by VPX_CODEC_CAP_* defines.
     51    */
     52 #define VPX_CODEC_CAP_PUT_SLICE  0x10000 /**< Will issue put_slice callbacks */
     53 #define VPX_CODEC_CAP_PUT_FRAME  0x20000 /**< Will issue put_frame callbacks */
     54 #define VPX_CODEC_CAP_POSTPROC   0x40000 /**< Can postprocess decoded frame */
     55 #define VPX_CODEC_CAP_ERROR_CONCEALMENT   0x80000 /**< Can conceal errors due to
     56   packet loss */
     57 #define VPX_CODEC_CAP_INPUT_FRAGMENTS   0x100000 /**< Can receive encoded frames
     58   one fragment at a time */
     59 
     60   /*! \brief Initialization-time Feature Enabling
     61    *
     62    *  Certain codec features must be known at initialization time, to allow for
     63    *  proper memory allocation.
     64    *
     65    *  The available flags are specified by VPX_CODEC_USE_* defines.
     66    */
     67 #define VPX_CODEC_CAP_FRAME_THREADING   0x200000 /**< Can support frame-based
     68                                                       multi-threading */
     69 
     70 #define VPX_CODEC_USE_POSTPROC   0x10000 /**< Postprocess decoded frame */
     71 #define VPX_CODEC_USE_ERROR_CONCEALMENT 0x20000 /**< Conceal errors in decoded
     72   frames */
     73 #define VPX_CODEC_USE_INPUT_FRAGMENTS   0x40000 /**< The input frame should be
     74   passed to the decoder one
     75   fragment at a time */
     76 #define VPX_CODEC_USE_FRAME_THREADING   0x80000 /**< Enable frame-based
     77                                                      multi-threading */
     78 
     79   /*!\brief Stream properties
     80    *
     81    * This structure is used to query or set properties of the decoded
     82    * stream. Algorithms may extend this structure with data specific
     83    * to their bitstream by setting the sz member appropriately.
     84    */
     85   typedef struct vpx_codec_stream_info {
     86     unsigned int sz;     /**< Size of this structure */
     87     unsigned int w;      /**< Width (or 0 for unknown/default) */
     88     unsigned int h;      /**< Height (or 0 for unknown/default) */
     89     unsigned int is_kf;  /**< Current frame is a keyframe */
     90   } vpx_codec_stream_info_t;
     91 
     92   /* REQUIRED FUNCTIONS
     93    *
     94    * The following functions are required to be implemented for all decoders.
     95    * They represent the base case functionality expected of all decoders.
     96    */
     97 
     98 
     99   /*!\brief Initialization Configurations
    100    *
    101    * This structure is used to pass init time configuration options to the
    102    * decoder.
    103    */
    104   typedef struct vpx_codec_dec_cfg {
    105     unsigned int threads; /**< Maximum number of threads to use, default 1 */
    106     unsigned int w;      /**< Width */
    107     unsigned int h;      /**< Height */
    108   } vpx_codec_dec_cfg_t; /**< alias for struct vpx_codec_dec_cfg */
    109 
    110 
    111   /*!\brief Initialize a decoder instance
    112    *
    113    * Initializes a decoder context using the given interface. Applications
    114    * should call the vpx_codec_dec_init convenience macro instead of this
    115    * function directly, to ensure that the ABI version number parameter
    116    * is properly initialized.
    117    *
    118    * If the library was configured with --disable-multithread, this call
    119    * is not thread safe and should be guarded with a lock if being used
    120    * in a multithreaded context.
    121    *
    122    * In XMA mode (activated by setting VPX_CODEC_USE_XMA in the flags
    123    * parameter), the storage pointed to by the cfg parameter must be
    124    * kept readable and stable until all memory maps have been set.
    125    *
    126    * \param[in]    ctx     Pointer to this instance's context.
    127    * \param[in]    iface   Pointer to the algorithm interface to use.
    128    * \param[in]    cfg     Configuration to use, if known. May be NULL.
    129    * \param[in]    flags   Bitfield of VPX_CODEC_USE_* flags
    130    * \param[in]    ver     ABI version number. Must be set to
    131    *                       VPX_DECODER_ABI_VERSION
    132    * \retval #VPX_CODEC_OK
    133    *     The decoder algorithm initialized.
    134    * \retval #VPX_CODEC_MEM_ERROR
    135    *     Memory allocation failed.
    136    */
    137   vpx_codec_err_t vpx_codec_dec_init_ver(vpx_codec_ctx_t      *ctx,
    138                                          vpx_codec_iface_t    *iface,
    139                                          vpx_codec_dec_cfg_t  *cfg,
    140                                          vpx_codec_flags_t     flags,
    141                                          int                   ver);
    142 
    143   /*!\brief Convenience macro for vpx_codec_dec_init_ver()
    144    *
    145    * Ensures the ABI version parameter is properly set.
    146    */
    147 #define vpx_codec_dec_init(ctx, iface, cfg, flags) \
    148   vpx_codec_dec_init_ver(ctx, iface, cfg, flags, VPX_DECODER_ABI_VERSION)
    149 
    150 
    151   /*!\brief Parse stream info from a buffer
    152    *
    153    * Performs high level parsing of the bitstream. Construction of a decoder
    154    * context is not necessary. Can be used to determine if the bitstream is
    155    * of the proper format, and to extract information from the stream.
    156    *
    157    * \param[in]      iface   Pointer to the algorithm interface
    158    * \param[in]      data    Pointer to a block of data to parse
    159    * \param[in]      data_sz Size of the data buffer
    160    * \param[in,out]  si      Pointer to stream info to update. The size member
    161    *                         \ref MUST be properly initialized, but \ref MAY be
    162    *                         clobbered by the algorithm. This parameter \ref MAY
    163    *                         be NULL.
    164    *
    165    * \retval #VPX_CODEC_OK
    166    *     Bitstream is parsable and stream information updated
    167    */
    168   vpx_codec_err_t vpx_codec_peek_stream_info(vpx_codec_iface_t       *iface,
    169                                              const uint8_t           *data,
    170                                              unsigned int             data_sz,
    171                                              vpx_codec_stream_info_t *si);
    172 
    173 
    174   /*!\brief Return information about the current stream.
    175    *
    176    * Returns information about the stream that has been parsed during decoding.
    177    *
    178    * \param[in]      ctx     Pointer to this instance's context
    179    * \param[in,out]  si      Pointer to stream info to update. The size member
    180    *                         \ref MUST be properly initialized, but \ref MAY be
    181    *                         clobbered by the algorithm. This parameter \ref MAY
    182    *                         be NULL.
    183    *
    184    * \retval #VPX_CODEC_OK
    185    *     Bitstream is parsable and stream information updated
    186    */
    187   vpx_codec_err_t vpx_codec_get_stream_info(vpx_codec_ctx_t         *ctx,
    188                                             vpx_codec_stream_info_t *si);
    189 
    190 
    191   /*!\brief Decode data
    192    *
    193    * Processes a buffer of coded data. If the processing results in a new
    194    * decoded frame becoming available, PUT_SLICE and PUT_FRAME events may be
    195    * generated, as appropriate. Encoded data \ref MUST be passed in DTS (decode
    196    * time stamp) order. Frames produced will always be in PTS (presentation
    197    * time stamp) order.
    198    * If the decoder is configured with VPX_CODEC_USE_INPUT_FRAGMENTS enabled,
    199    * data and data_sz can contain a fragment of the encoded frame. Fragment
    200    * \#n must contain at least partition \#n, but can also contain subsequent
    201    * partitions (\#n+1 - \#n+i), and if so, fragments \#n+1, .., \#n+i must
    202    * be empty. When no more data is available, this function should be called
    203    * with NULL as data and 0 as data_sz. The memory passed to this function
    204    * must be available until the frame has been decoded.
    205    *
    206    * \param[in] ctx          Pointer to this instance's context
    207    * \param[in] data         Pointer to this block of new coded data. If
    208    *                         NULL, a VPX_CODEC_CB_PUT_FRAME event is posted
    209    *                         for the previously decoded frame.
    210    * \param[in] data_sz      Size of the coded data, in bytes.
    211    * \param[in] user_priv    Application specific data to associate with
    212    *                         this frame.
    213    * \param[in] deadline     Soft deadline the decoder should attempt to meet,
    214    *                         in us. Set to zero for unlimited.
    215    *
    216    * \return Returns #VPX_CODEC_OK if the coded data was processed completely
    217    *         and future pictures can be decoded without error. Otherwise,
    218    *         see the descriptions of the other error codes in ::vpx_codec_err_t
    219    *         for recoverability capabilities.
    220    */
    221   vpx_codec_err_t vpx_codec_decode(vpx_codec_ctx_t    *ctx,
    222                                    const uint8_t        *data,
    223                                    unsigned int            data_sz,
    224                                    void               *user_priv,
    225                                    long                deadline);
    226 
    227 
    228   /*!\brief Decoded frames iterator
    229    *
    230    * Iterates over a list of the frames available for display. The iterator
    231    * storage should be initialized to NULL to start the iteration. Iteration is
    232    * complete when this function returns NULL.
    233    *
    234    * The list of available frames becomes valid upon completion of the
    235    * vpx_codec_decode call, and remains valid until the next call to vpx_codec_decode.
    236    *
    237    * \param[in]     ctx      Pointer to this instance's context
    238    * \param[in,out] iter     Iterator storage, initialized to NULL
    239    *
    240    * \return Returns a pointer to an image, if one is ready for display. Frames
    241    *         produced will always be in PTS (presentation time stamp) order.
    242    */
    243   vpx_image_t *vpx_codec_get_frame(vpx_codec_ctx_t  *ctx,
    244                                    vpx_codec_iter_t *iter);
    245 
    246 
    247   /*!\defgroup cap_put_frame Frame-Based Decoding Functions
    248    *
    249    * The following functions are required to be implemented for all decoders
    250    * that advertise the VPX_CODEC_CAP_PUT_FRAME capability. Calling these functions
    251    * for codecs that don't advertise this capability will result in an error
    252    * code being returned, usually VPX_CODEC_ERROR
    253    * @{
    254    */
    255 
    256   /*!\brief put frame callback prototype
    257    *
    258    * This callback is invoked by the decoder to notify the application of
    259    * the availability of decoded image data.
    260    */
    261   typedef void (*vpx_codec_put_frame_cb_fn_t)(void        *user_priv,
    262                                               const vpx_image_t *img);
    263 
    264 
    265   /*!\brief Register for notification of frame completion.
    266    *
    267    * Registers a given function to be called when a decoded frame is
    268    * available.
    269    *
    270    * \param[in] ctx          Pointer to this instance's context
    271    * \param[in] cb           Pointer to the callback function
    272    * \param[in] user_priv    User's private data
    273    *
    274    * \retval #VPX_CODEC_OK
    275    *     Callback successfully registered.
    276    * \retval #VPX_CODEC_ERROR
    277    *     Decoder context not initialized, or algorithm not capable of
    278    *     posting slice completion.
    279    */
    280   vpx_codec_err_t vpx_codec_register_put_frame_cb(vpx_codec_ctx_t             *ctx,
    281                                                   vpx_codec_put_frame_cb_fn_t  cb,
    282                                                   void                        *user_priv);
    283 
    284 
    285   /*!@} - end defgroup cap_put_frame */
    286 
    287   /*!\defgroup cap_put_slice Slice-Based Decoding Functions
    288    *
    289    * The following functions are required to be implemented for all decoders
    290    * that advertise the VPX_CODEC_CAP_PUT_SLICE capability. Calling these functions
    291    * for codecs that don't advertise this capability will result in an error
    292    * code being returned, usually VPX_CODEC_ERROR
    293    * @{
    294    */
    295 
    296   /*!\brief put slice callback prototype
    297    *
    298    * This callback is invoked by the decoder to notify the application of
    299    * the availability of partially decoded image data. The
    300    */
    301   typedef void (*vpx_codec_put_slice_cb_fn_t)(void         *user_priv,
    302                                               const vpx_image_t      *img,
    303                                               const vpx_image_rect_t *valid,
    304                                               const vpx_image_rect_t *update);
    305 
    306 
    307   /*!\brief Register for notification of slice completion.
    308    *
    309    * Registers a given function to be called when a decoded slice is
    310    * available.
    311    *
    312    * \param[in] ctx          Pointer to this instance's context
    313    * \param[in] cb           Pointer to the callback function
    314    * \param[in] user_priv    User's private data
    315    *
    316    * \retval #VPX_CODEC_OK
    317    *     Callback successfully registered.
    318    * \retval #VPX_CODEC_ERROR
    319    *     Decoder context not initialized, or algorithm not capable of
    320    *     posting slice completion.
    321    */
    322   vpx_codec_err_t vpx_codec_register_put_slice_cb(vpx_codec_ctx_t             *ctx,
    323                                                   vpx_codec_put_slice_cb_fn_t  cb,
    324                                                   void                        *user_priv);
    325 
    326 
    327   /*!@} - end defgroup cap_put_slice*/
    328 
    329   /*!@} - end defgroup decoder*/
    330 #ifdef __cplusplus
    331 }
    332 #endif
    333 #endif
    334 
    335