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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_VPX_DECODER_H_
     11 #define VPX_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 #include "./vpx_frame_buffer.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 \
     44   (3 + VPX_CODEC_ABI_VERSION) /**<\hideinitializer*/
     45 
     46 /*! \brief Decoder capabilities bitfield
     47  *
     48  *  Each decoder advertises the capabilities it supports as part of its
     49  *  ::vpx_codec_iface_t interface structure. Capabilities are extra interfaces
     50  *  or functionality, and are not required to be supported by a decoder.
     51  *
     52  *  The available flags are specified by VPX_CODEC_CAP_* defines.
     53  */
     54 #define VPX_CODEC_CAP_PUT_SLICE 0x10000 /**< Will issue put_slice callbacks */
     55 #define VPX_CODEC_CAP_PUT_FRAME 0x20000 /**< Will issue put_frame callbacks */
     56 #define VPX_CODEC_CAP_POSTPROC 0x40000  /**< Can postprocess decoded frame */
     57 /*!\brief Can conceal errors due to packet loss */
     58 #define VPX_CODEC_CAP_ERROR_CONCEALMENT 0x80000
     59 /*!\brief Can receive encoded frames one fragment at a time */
     60 #define VPX_CODEC_CAP_INPUT_FRAGMENTS 0x100000
     61 
     62 /*! \brief Initialization-time Feature Enabling
     63  *
     64  *  Certain codec features must be known at initialization time, to allow for
     65  *  proper memory allocation.
     66  *
     67  *  The available flags are specified by VPX_CODEC_USE_* defines.
     68  */
     69 /*!\brief Can support frame-based multi-threading */
     70 #define VPX_CODEC_CAP_FRAME_THREADING 0x200000
     71 /*!brief Can support external frame buffers */
     72 #define VPX_CODEC_CAP_EXTERNAL_FRAME_BUFFER 0x400000
     73 
     74 #define VPX_CODEC_USE_POSTPROC 0x10000 /**< Postprocess decoded frame */
     75 /*!\brief Conceal errors in decoded frames */
     76 #define VPX_CODEC_USE_ERROR_CONCEALMENT 0x20000
     77 /*!\brief The input frame should be passed to the decoder one fragment at a
     78  * time */
     79 #define VPX_CODEC_USE_INPUT_FRAGMENTS 0x40000
     80 /*!\brief Enable frame-based multi-threading */
     81 #define VPX_CODEC_USE_FRAME_THREADING 0x80000
     82 
     83 /*!\brief Stream properties
     84  *
     85  * This structure is used to query or set properties of the decoded
     86  * stream. Algorithms may extend this structure with data specific
     87  * to their bitstream by setting the sz member appropriately.
     88  */
     89 typedef struct vpx_codec_stream_info {
     90   unsigned int sz;    /**< Size of this structure */
     91   unsigned int w;     /**< Width (or 0 for unknown/default) */
     92   unsigned int h;     /**< Height (or 0 for unknown/default) */
     93   unsigned int is_kf; /**< Current frame is a keyframe */
     94 } vpx_codec_stream_info_t;
     95 
     96 /* REQUIRED FUNCTIONS
     97  *
     98  * The following functions are required to be implemented for all decoders.
     99  * They represent the base case functionality expected of all decoders.
    100  */
    101 
    102 /*!\brief Initialization Configurations
    103  *
    104  * This structure is used to pass init time configuration options to the
    105  * decoder.
    106  */
    107 typedef struct vpx_codec_dec_cfg {
    108   unsigned int threads; /**< Maximum number of threads to use, default 1 */
    109   unsigned int w;       /**< Width */
    110   unsigned int h;       /**< Height */
    111 } vpx_codec_dec_cfg_t;  /**< alias for struct vpx_codec_dec_cfg */
    112 
    113 /*!\brief Initialize a decoder instance
    114  *
    115  * Initializes a decoder context using the given interface. Applications
    116  * should call the vpx_codec_dec_init convenience macro instead of this
    117  * function directly, to ensure that the ABI version number parameter
    118  * is properly initialized.
    119  *
    120  * If the library was configured with --disable-multithread, this call
    121  * is not thread safe and should be guarded with a lock if being used
    122  * in a multithreaded context.
    123  *
    124  * \param[in]    ctx     Pointer to this instance's context.
    125  * \param[in]    iface   Pointer to the algorithm interface to use.
    126  * \param[in]    cfg     Configuration to use, if known. May be NULL.
    127  * \param[in]    flags   Bitfield of VPX_CODEC_USE_* flags
    128  * \param[in]    ver     ABI version number. Must be set to
    129  *                       VPX_DECODER_ABI_VERSION
    130  * \retval #VPX_CODEC_OK
    131  *     The decoder algorithm initialized.
    132  * \retval #VPX_CODEC_MEM_ERROR
    133  *     Memory allocation failed.
    134  */
    135 vpx_codec_err_t vpx_codec_dec_init_ver(vpx_codec_ctx_t *ctx,
    136                                        vpx_codec_iface_t *iface,
    137                                        const vpx_codec_dec_cfg_t *cfg,
    138                                        vpx_codec_flags_t flags, int ver);
    139 
    140 /*!\brief Convenience macro for vpx_codec_dec_init_ver()
    141  *
    142  * Ensures the ABI version parameter is properly set.
    143  */
    144 #define vpx_codec_dec_init(ctx, iface, cfg, flags) \
    145   vpx_codec_dec_init_ver(ctx, iface, cfg, flags, VPX_DECODER_ABI_VERSION)
    146 
    147 /*!\brief Parse stream info from a buffer
    148  *
    149  * Performs high level parsing of the bitstream. Construction of a decoder
    150  * context is not necessary. Can be used to determine if the bitstream is
    151  * of the proper format, and to extract information from the stream.
    152  *
    153  * \param[in]      iface   Pointer to the algorithm interface
    154  * \param[in]      data    Pointer to a block of data to parse
    155  * \param[in]      data_sz Size of the data buffer
    156  * \param[in,out]  si      Pointer to stream info to update. The size member
    157  *                         \ref MUST be properly initialized, but \ref MAY be
    158  *                         clobbered by the algorithm. This parameter \ref MAY
    159  *                         be NULL.
    160  *
    161  * \retval #VPX_CODEC_OK
    162  *     Bitstream is parsable and stream information updated
    163  */
    164 vpx_codec_err_t vpx_codec_peek_stream_info(vpx_codec_iface_t *iface,
    165                                            const uint8_t *data,
    166                                            unsigned int data_sz,
    167                                            vpx_codec_stream_info_t *si);
    168 
    169 /*!\brief Return information about the current stream.
    170  *
    171  * Returns information about the stream that has been parsed during decoding.
    172  *
    173  * \param[in]      ctx     Pointer to this instance's context
    174  * \param[in,out]  si      Pointer to stream info to update. The size member
    175  *                         \ref MUST be properly initialized, but \ref MAY be
    176  *                         clobbered by the algorithm. This parameter \ref MAY
    177  *                         be NULL.
    178  *
    179  * \retval #VPX_CODEC_OK
    180  *     Bitstream is parsable and stream information updated
    181  */
    182 vpx_codec_err_t vpx_codec_get_stream_info(vpx_codec_ctx_t *ctx,
    183                                           vpx_codec_stream_info_t *si);
    184 
    185 /*!\brief Decode data
    186  *
    187  * Processes a buffer of coded data. If the processing results in a new
    188  * decoded frame becoming available, PUT_SLICE and PUT_FRAME events may be
    189  * generated, as appropriate. Encoded data \ref MUST be passed in DTS (decode
    190  * time stamp) order. Frames produced will always be in PTS (presentation
    191  * time stamp) order.
    192  * If the decoder is configured with VPX_CODEC_USE_INPUT_FRAGMENTS enabled,
    193  * data and data_sz can contain a fragment of the encoded frame. Fragment
    194  * \#n must contain at least partition \#n, but can also contain subsequent
    195  * partitions (\#n+1 - \#n+i), and if so, fragments \#n+1, .., \#n+i must
    196  * be empty. When no more data is available, this function should be called
    197  * with NULL as data and 0 as data_sz. The memory passed to this function
    198  * must be available until the frame has been decoded.
    199  *
    200  * \param[in] ctx          Pointer to this instance's context
    201  * \param[in] data         Pointer to this block of new coded data. If
    202  *                         NULL, a VPX_CODEC_CB_PUT_FRAME event is posted
    203  *                         for the previously decoded frame.
    204  * \param[in] data_sz      Size of the coded data, in bytes.
    205  * \param[in] user_priv    Application specific data to associate with
    206  *                         this frame.
    207  * \param[in] deadline     Soft deadline the decoder should attempt to meet,
    208  *                         in us. Set to zero for unlimited.
    209  *
    210  * \return Returns #VPX_CODEC_OK if the coded data was processed completely
    211  *         and future pictures can be decoded without error. Otherwise,
    212  *         see the descriptions of the other error codes in ::vpx_codec_err_t
    213  *         for recoverability capabilities.
    214  */
    215 vpx_codec_err_t vpx_codec_decode(vpx_codec_ctx_t *ctx, const uint8_t *data,
    216                                  unsigned int data_sz, void *user_priv,
    217                                  long deadline);
    218 
    219 /*!\brief Decoded frames iterator
    220  *
    221  * Iterates over a list of the frames available for display. The iterator
    222  * storage should be initialized to NULL to start the iteration. Iteration is
    223  * complete when this function returns NULL.
    224  *
    225  * The list of available frames becomes valid upon completion of the
    226  * vpx_codec_decode call, and remains valid until the next call to
    227  * vpx_codec_decode.
    228  *
    229  * \param[in]     ctx      Pointer to this instance's context
    230  * \param[in,out] iter     Iterator storage, initialized to NULL
    231  *
    232  * \return Returns a pointer to an image, if one is ready for display. Frames
    233  *         produced will always be in PTS (presentation time stamp) order.
    234  */
    235 vpx_image_t *vpx_codec_get_frame(vpx_codec_ctx_t *ctx, vpx_codec_iter_t *iter);
    236 
    237 /*!\defgroup cap_put_frame Frame-Based Decoding Functions
    238  *
    239  * The following functions are required to be implemented for all decoders
    240  * that advertise the VPX_CODEC_CAP_PUT_FRAME capability. Calling these
    241  * functions
    242  * for codecs that don't advertise this capability will result in an error
    243  * code being returned, usually VPX_CODEC_ERROR
    244  * @{
    245  */
    246 
    247 /*!\brief put frame callback prototype
    248  *
    249  * This callback is invoked by the decoder to notify the application of
    250  * the availability of decoded image data.
    251  */
    252 typedef void (*vpx_codec_put_frame_cb_fn_t)(void *user_priv,
    253                                             const vpx_image_t *img);
    254 
    255 /*!\brief Register for notification of frame completion.
    256  *
    257  * Registers a given function to be called when a decoded frame is
    258  * available.
    259  *
    260  * \param[in] ctx          Pointer to this instance's context
    261  * \param[in] cb           Pointer to the callback function
    262  * \param[in] user_priv    User's private data
    263  *
    264  * \retval #VPX_CODEC_OK
    265  *     Callback successfully registered.
    266  * \retval #VPX_CODEC_ERROR
    267  *     Decoder context not initialized, or algorithm not capable of
    268  *     posting slice completion.
    269  */
    270 vpx_codec_err_t vpx_codec_register_put_frame_cb(vpx_codec_ctx_t *ctx,
    271                                                 vpx_codec_put_frame_cb_fn_t cb,
    272                                                 void *user_priv);
    273 
    274 /*!@} - end defgroup cap_put_frame */
    275 
    276 /*!\defgroup cap_put_slice Slice-Based Decoding Functions
    277  *
    278  * The following functions are required to be implemented for all decoders
    279  * that advertise the VPX_CODEC_CAP_PUT_SLICE capability. Calling these
    280  * functions
    281  * for codecs that don't advertise this capability will result in an error
    282  * code being returned, usually VPX_CODEC_ERROR
    283  * @{
    284  */
    285 
    286 /*!\brief put slice callback prototype
    287  *
    288  * This callback is invoked by the decoder to notify the application of
    289  * the availability of partially decoded image data. The
    290  */
    291 typedef void (*vpx_codec_put_slice_cb_fn_t)(void *user_priv,
    292                                             const vpx_image_t *img,
    293                                             const vpx_image_rect_t *valid,
    294                                             const vpx_image_rect_t *update);
    295 
    296 /*!\brief Register for notification of slice completion.
    297  *
    298  * Registers a given function to be called when a decoded slice is
    299  * available.
    300  *
    301  * \param[in] ctx          Pointer to this instance's context
    302  * \param[in] cb           Pointer to the callback function
    303  * \param[in] user_priv    User's private data
    304  *
    305  * \retval #VPX_CODEC_OK
    306  *     Callback successfully registered.
    307  * \retval #VPX_CODEC_ERROR
    308  *     Decoder context not initialized, or algorithm not capable of
    309  *     posting slice completion.
    310  */
    311 vpx_codec_err_t vpx_codec_register_put_slice_cb(vpx_codec_ctx_t *ctx,
    312                                                 vpx_codec_put_slice_cb_fn_t cb,
    313                                                 void *user_priv);
    314 
    315 /*!@} - end defgroup cap_put_slice*/
    316 
    317 /*!\defgroup cap_external_frame_buffer External Frame Buffer Functions
    318  *
    319  * The following section is required to be implemented for all decoders
    320  * that advertise the VPX_CODEC_CAP_EXTERNAL_FRAME_BUFFER capability.
    321  * Calling this function for codecs that don't advertise this capability
    322  * will result in an error code being returned, usually VPX_CODEC_ERROR.
    323  *
    324  * \note
    325  * Currently this only works with VP9.
    326  * @{
    327  */
    328 
    329 /*!\brief Pass in external frame buffers for the decoder to use.
    330  *
    331  * Registers functions to be called when libvpx needs a frame buffer
    332  * to decode the current frame and a function to be called when libvpx does
    333  * not internally reference the frame buffer. This set function must
    334  * be called before the first call to decode or libvpx will assume the
    335  * default behavior of allocating frame buffers internally.
    336  *
    337  * \param[in] ctx          Pointer to this instance's context
    338  * \param[in] cb_get       Pointer to the get callback function
    339  * \param[in] cb_release   Pointer to the release callback function
    340  * \param[in] cb_priv      Callback's private data
    341  *
    342  * \retval #VPX_CODEC_OK
    343  *     External frame buffers will be used by libvpx.
    344  * \retval #VPX_CODEC_INVALID_PARAM
    345  *     One or more of the callbacks were NULL.
    346  * \retval #VPX_CODEC_ERROR
    347  *     Decoder context not initialized, or algorithm not capable of
    348  *     using external frame buffers.
    349  *
    350  * \note
    351  * When decoding VP9, the application may be required to pass in at least
    352  * #VP9_MAXIMUM_REF_BUFFERS + #VPX_MAXIMUM_WORK_BUFFERS external frame
    353  * buffers.
    354  */
    355 vpx_codec_err_t vpx_codec_set_frame_buffer_functions(
    356     vpx_codec_ctx_t *ctx, vpx_get_frame_buffer_cb_fn_t cb_get,
    357     vpx_release_frame_buffer_cb_fn_t cb_release, void *cb_priv);
    358 
    359 /*!@} - end defgroup cap_external_frame_buffer */
    360 
    361 /*!@} - end defgroup decoder*/
    362 #ifdef __cplusplus
    363 }
    364 #endif
    365 #endif  // VPX_VPX_DECODER_H_
    366