Home | History | Annotate | Download | only in vpx
      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 (3 + 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 #define VPX_CODEC_CAP_ERROR_CONCEALMENT   0x80000 /**< Can conceal errors due to
     57   packet loss */
     58 #define VPX_CODEC_CAP_INPUT_FRAGMENTS   0x100000 /**< Can receive encoded frames
     59   one fragment at a time */
     60 
     61   /*! \brief Initialization-time Feature Enabling
     62    *
     63    *  Certain codec features must be known at initialization time, to allow for
     64    *  proper memory allocation.
     65    *
     66    *  The available flags are specified by VPX_CODEC_USE_* defines.
     67    */
     68 #define VPX_CODEC_CAP_FRAME_THREADING   0x200000 /**< Can support frame-based
     69                                                       multi-threading */
     70 #define VPX_CODEC_CAP_EXTERNAL_FRAME_BUFFER 0x400000 /**< Can support external
     71                                                           frame buffers */
     72 
     73 #define VPX_CODEC_USE_POSTPROC   0x10000 /**< Postprocess decoded frame */
     74 #define VPX_CODEC_USE_ERROR_CONCEALMENT 0x20000 /**< Conceal errors in decoded
     75   frames */
     76 #define VPX_CODEC_USE_INPUT_FRAGMENTS   0x40000 /**< The input frame should be
     77   passed to the decoder one
     78   fragment at a time */
     79 #define VPX_CODEC_USE_FRAME_THREADING   0x80000 /**< Enable frame-based
     80                                                      multi-threading */
     81 
     82   /*!\brief Stream properties
     83    *
     84    * This structure is used to query or set properties of the decoded
     85    * stream. Algorithms may extend this structure with data specific
     86    * to their bitstream by setting the sz member appropriately.
     87    */
     88   typedef struct vpx_codec_stream_info {
     89     unsigned int sz;     /**< Size of this structure */
     90     unsigned int w;      /**< Width (or 0 for unknown/default) */
     91     unsigned int h;      /**< Height (or 0 for unknown/default) */
     92     unsigned int is_kf;  /**< Current frame is a keyframe */
     93   } vpx_codec_stream_info_t;
     94 
     95   /* REQUIRED FUNCTIONS
     96    *
     97    * The following functions are required to be implemented for all decoders.
     98    * They represent the base case functionality expected of all decoders.
     99    */
    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 
    114   /*!\brief Initialize a decoder instance
    115    *
    116    * Initializes a decoder context using the given interface. Applications
    117    * should call the vpx_codec_dec_init convenience macro instead of this
    118    * function directly, to ensure that the ABI version number parameter
    119    * is properly initialized.
    120    *
    121    * If the library was configured with --disable-multithread, this call
    122    * is not thread safe and should be guarded with a lock if being used
    123    * in a multithreaded context.
    124    *
    125    * In XMA mode (activated by setting VPX_CODEC_USE_XMA in the flags
    126    * parameter), the storage pointed to by the cfg parameter must be
    127    * kept readable and stable until all memory maps have been set.
    128    *
    129    * \param[in]    ctx     Pointer to this instance's context.
    130    * \param[in]    iface   Pointer to the algorithm interface to use.
    131    * \param[in]    cfg     Configuration to use, if known. May be NULL.
    132    * \param[in]    flags   Bitfield of VPX_CODEC_USE_* flags
    133    * \param[in]    ver     ABI version number. Must be set to
    134    *                       VPX_DECODER_ABI_VERSION
    135    * \retval #VPX_CODEC_OK
    136    *     The decoder algorithm initialized.
    137    * \retval #VPX_CODEC_MEM_ERROR
    138    *     Memory allocation failed.
    139    */
    140   vpx_codec_err_t vpx_codec_dec_init_ver(vpx_codec_ctx_t      *ctx,
    141                                          vpx_codec_iface_t    *iface,
    142                                          vpx_codec_dec_cfg_t  *cfg,
    143                                          vpx_codec_flags_t     flags,
    144                                          int                   ver);
    145 
    146   /*!\brief Convenience macro for vpx_codec_dec_init_ver()
    147    *
    148    * Ensures the ABI version parameter is properly set.
    149    */
    150 #define vpx_codec_dec_init(ctx, iface, cfg, flags) \
    151   vpx_codec_dec_init_ver(ctx, iface, cfg, flags, VPX_DECODER_ABI_VERSION)
    152 
    153 
    154   /*!\brief Parse stream info from a buffer
    155    *
    156    * Performs high level parsing of the bitstream. Construction of a decoder
    157    * context is not necessary. Can be used to determine if the bitstream is
    158    * of the proper format, and to extract information from the stream.
    159    *
    160    * \param[in]      iface   Pointer to the algorithm interface
    161    * \param[in]      data    Pointer to a block of data to parse
    162    * \param[in]      data_sz Size of the data buffer
    163    * \param[in,out]  si      Pointer to stream info to update. The size member
    164    *                         \ref MUST be properly initialized, but \ref MAY be
    165    *                         clobbered by the algorithm. This parameter \ref MAY
    166    *                         be NULL.
    167    *
    168    * \retval #VPX_CODEC_OK
    169    *     Bitstream is parsable and stream information updated
    170    */
    171   vpx_codec_err_t vpx_codec_peek_stream_info(vpx_codec_iface_t       *iface,
    172                                              const uint8_t           *data,
    173                                              unsigned int             data_sz,
    174                                              vpx_codec_stream_info_t *si);
    175 
    176 
    177   /*!\brief Return information about the current stream.
    178    *
    179    * Returns information about the stream that has been parsed during decoding.
    180    *
    181    * \param[in]      ctx     Pointer to this instance's context
    182    * \param[in,out]  si      Pointer to stream info to update. The size member
    183    *                         \ref MUST be properly initialized, but \ref MAY be
    184    *                         clobbered by the algorithm. This parameter \ref MAY
    185    *                         be NULL.
    186    *
    187    * \retval #VPX_CODEC_OK
    188    *     Bitstream is parsable and stream information updated
    189    */
    190   vpx_codec_err_t vpx_codec_get_stream_info(vpx_codec_ctx_t         *ctx,
    191                                             vpx_codec_stream_info_t *si);
    192 
    193 
    194   /*!\brief Decode data
    195    *
    196    * Processes a buffer of coded data. If the processing results in a new
    197    * decoded frame becoming available, PUT_SLICE and PUT_FRAME events may be
    198    * generated, as appropriate. Encoded data \ref MUST be passed in DTS (decode
    199    * time stamp) order. Frames produced will always be in PTS (presentation
    200    * time stamp) order.
    201    * If the decoder is configured with VPX_CODEC_USE_INPUT_FRAGMENTS enabled,
    202    * data and data_sz can contain a fragment of the encoded frame. Fragment
    203    * \#n must contain at least partition \#n, but can also contain subsequent
    204    * partitions (\#n+1 - \#n+i), and if so, fragments \#n+1, .., \#n+i must
    205    * be empty. When no more data is available, this function should be called
    206    * with NULL as data and 0 as data_sz. The memory passed to this function
    207    * must be available until the frame has been decoded.
    208    *
    209    * \param[in] ctx          Pointer to this instance's context
    210    * \param[in] data         Pointer to this block of new coded data. If
    211    *                         NULL, a VPX_CODEC_CB_PUT_FRAME event is posted
    212    *                         for the previously decoded frame.
    213    * \param[in] data_sz      Size of the coded data, in bytes.
    214    * \param[in] user_priv    Application specific data to associate with
    215    *                         this frame.
    216    * \param[in] deadline     Soft deadline the decoder should attempt to meet,
    217    *                         in us. Set to zero for unlimited.
    218    *
    219    * \return Returns #VPX_CODEC_OK if the coded data was processed completely
    220    *         and future pictures can be decoded without error. Otherwise,
    221    *         see the descriptions of the other error codes in ::vpx_codec_err_t
    222    *         for recoverability capabilities.
    223    */
    224   vpx_codec_err_t vpx_codec_decode(vpx_codec_ctx_t    *ctx,
    225                                    const uint8_t        *data,
    226                                    unsigned int            data_sz,
    227                                    void               *user_priv,
    228                                    long                deadline);
    229 
    230 
    231   /*!\brief Decoded frames iterator
    232    *
    233    * Iterates over a list of the frames available for display. The iterator
    234    * storage should be initialized to NULL to start the iteration. Iteration is
    235    * complete when this function returns NULL.
    236    *
    237    * The list of available frames becomes valid upon completion of the
    238    * vpx_codec_decode call, and remains valid until the next call to vpx_codec_decode.
    239    *
    240    * \param[in]     ctx      Pointer to this instance's context
    241    * \param[in,out] iter     Iterator storage, initialized to NULL
    242    *
    243    * \return Returns a pointer to an image, if one is ready for display. Frames
    244    *         produced will always be in PTS (presentation time stamp) order.
    245    */
    246   vpx_image_t *vpx_codec_get_frame(vpx_codec_ctx_t  *ctx,
    247                                    vpx_codec_iter_t *iter);
    248 
    249 
    250   /*!\defgroup cap_put_frame Frame-Based Decoding Functions
    251    *
    252    * The following functions are required to be implemented for all decoders
    253    * that advertise the VPX_CODEC_CAP_PUT_FRAME capability. Calling these functions
    254    * for codecs that don't advertise this capability will result in an error
    255    * code being returned, usually VPX_CODEC_ERROR
    256    * @{
    257    */
    258 
    259   /*!\brief put frame callback prototype
    260    *
    261    * This callback is invoked by the decoder to notify the application of
    262    * the availability of decoded image data.
    263    */
    264   typedef void (*vpx_codec_put_frame_cb_fn_t)(void        *user_priv,
    265                                               const vpx_image_t *img);
    266 
    267 
    268   /*!\brief Register for notification of frame completion.
    269    *
    270    * Registers a given function to be called when a decoded frame is
    271    * available.
    272    *
    273    * \param[in] ctx          Pointer to this instance's context
    274    * \param[in] cb           Pointer to the callback function
    275    * \param[in] user_priv    User's private data
    276    *
    277    * \retval #VPX_CODEC_OK
    278    *     Callback successfully registered.
    279    * \retval #VPX_CODEC_ERROR
    280    *     Decoder context not initialized, or algorithm not capable of
    281    *     posting slice completion.
    282    */
    283   vpx_codec_err_t vpx_codec_register_put_frame_cb(vpx_codec_ctx_t             *ctx,
    284                                                   vpx_codec_put_frame_cb_fn_t  cb,
    285                                                   void                        *user_priv);
    286 
    287 
    288   /*!@} - end defgroup cap_put_frame */
    289 
    290   /*!\defgroup cap_put_slice Slice-Based Decoding Functions
    291    *
    292    * The following functions are required to be implemented for all decoders
    293    * that advertise the VPX_CODEC_CAP_PUT_SLICE capability. Calling these functions
    294    * for codecs that don't advertise this capability will result in an error
    295    * code being returned, usually VPX_CODEC_ERROR
    296    * @{
    297    */
    298 
    299   /*!\brief put slice callback prototype
    300    *
    301    * This callback is invoked by the decoder to notify the application of
    302    * the availability of partially decoded image data. The
    303    */
    304   typedef void (*vpx_codec_put_slice_cb_fn_t)(void         *user_priv,
    305                                               const vpx_image_t      *img,
    306                                               const vpx_image_rect_t *valid,
    307                                               const vpx_image_rect_t *update);
    308 
    309 
    310   /*!\brief Register for notification of slice completion.
    311    *
    312    * Registers a given function to be called when a decoded slice is
    313    * available.
    314    *
    315    * \param[in] ctx          Pointer to this instance's context
    316    * \param[in] cb           Pointer to the callback function
    317    * \param[in] user_priv    User's private data
    318    *
    319    * \retval #VPX_CODEC_OK
    320    *     Callback successfully registered.
    321    * \retval #VPX_CODEC_ERROR
    322    *     Decoder context not initialized, or algorithm not capable of
    323    *     posting slice completion.
    324    */
    325   vpx_codec_err_t vpx_codec_register_put_slice_cb(vpx_codec_ctx_t             *ctx,
    326                                                   vpx_codec_put_slice_cb_fn_t  cb,
    327                                                   void                        *user_priv);
    328 
    329 
    330   /*!@} - end defgroup cap_put_slice*/
    331 
    332   /*!\defgroup cap_external_frame_buffer External Frame Buffer Functions
    333    *
    334    * The following section is required to be implemented for all decoders
    335    * that advertise the VPX_CODEC_CAP_EXTERNAL_FRAME_BUFFER capability.
    336    * Calling this function for codecs that don't advertise this capability
    337    * will result in an error code being returned, usually VPX_CODEC_ERROR.
    338    *
    339    * \note
    340    * Currently this only works with VP9.
    341    * @{
    342    */
    343 
    344   /*!\brief Pass in external frame buffers for the decoder to use.
    345    *
    346    * Registers functions to be called when libvpx needs a frame buffer
    347    * to decode the current frame and a function to be called when libvpx does
    348    * not internally reference the frame buffer. This set function must
    349    * be called before the first call to decode or libvpx will assume the
    350    * default behavior of allocating frame buffers internally.
    351    *
    352    * \param[in] ctx          Pointer to this instance's context
    353    * \param[in] cb_get       Pointer to the get callback function
    354    * \param[in] cb_release   Pointer to the release callback function
    355    * \param[in] cb_priv      Callback's private data
    356    *
    357    * \retval #VPX_CODEC_OK
    358    *     External frame buffers will be used by libvpx.
    359    * \retval #VPX_CODEC_INVALID_PARAM
    360    *     One or more of the callbacks were NULL.
    361    * \retval #VPX_CODEC_ERROR
    362    *     Decoder context not initialized, or algorithm not capable of
    363    *     using external frame buffers.
    364    *
    365    * \note
    366    * When decoding VP9, the application may be required to pass in at least
    367    * #VP9_MAXIMUM_REF_BUFFERS + #VPX_MAXIMUM_WORK_BUFFERS external frame
    368    * buffers.
    369    */
    370   vpx_codec_err_t vpx_codec_set_frame_buffer_functions(
    371       vpx_codec_ctx_t *ctx,
    372       vpx_get_frame_buffer_cb_fn_t cb_get,
    373       vpx_release_frame_buffer_cb_fn_t cb_release, void *cb_priv);
    374 
    375   /*!@} - end defgroup cap_external_frame_buffer */
    376 
    377   /*!@} - end defgroup decoder*/
    378 #ifdef __cplusplus
    379 }
    380 #endif
    381 #endif  // VPX_VPX_DECODER_H_
    382 
    383