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      1 /*
      2  *  Copyright (c) 2014 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 #ifndef VPX_VPX_FRAME_BUFFER_H_
     12 #define VPX_VPX_FRAME_BUFFER_H_
     13 
     14 /*!\file
     15  * \brief Describes the decoder external frame buffer interface.
     16  */
     17 
     18 #ifdef __cplusplus
     19 extern "C" {
     20 #endif
     21 
     22 #include "./vpx_integer.h"
     23 
     24 /*!\brief The maximum number of work buffers used by libvpx.
     25  *  Support maximum 4 threads to decode video in parallel.
     26  *  Each thread will use one work buffer.
     27  * TODO(hkuang): Add support to set number of worker threads dynamically.
     28  */
     29 #define VPX_MAXIMUM_WORK_BUFFERS 8
     30 
     31 /*!\brief The maximum number of reference buffers that a VP9 encoder may use.
     32  */
     33 #define VP9_MAXIMUM_REF_BUFFERS 8
     34 
     35 /*!\brief External frame buffer
     36  *
     37  * This structure holds allocated frame buffers used by the decoder.
     38  */
     39 typedef struct vpx_codec_frame_buffer {
     40   uint8_t *data; /**< Pointer to the data buffer */
     41   size_t size;   /**< Size of data in bytes */
     42   void *priv;    /**< Frame's private data */
     43 } vpx_codec_frame_buffer_t;
     44 
     45 /*!\brief get frame buffer callback prototype
     46  *
     47  * This callback is invoked by the decoder to retrieve data for the frame
     48  * buffer in order for the decode call to complete. The callback must
     49  * allocate at least min_size in bytes and assign it to fb->data. The callback
     50  * must zero out all the data allocated. Then the callback must set fb->size
     51  * to the allocated size. The application does not need to align the allocated
     52  * data. The callback is triggered when the decoder needs a frame buffer to
     53  * decode a compressed image into. This function may be called more than once
     54  * for every call to vpx_codec_decode. The application may set fb->priv to
     55  * some data which will be passed back in the ximage and the release function
     56  * call. |fb| is guaranteed to not be NULL. On success the callback must
     57  * return 0. Any failure the callback must return a value less than 0.
     58  *
     59  * \param[in] priv         Callback's private data
     60  * \param[in] new_size     Size in bytes needed by the buffer
     61  * \param[in,out] fb       Pointer to vpx_codec_frame_buffer_t
     62  */
     63 typedef int (*vpx_get_frame_buffer_cb_fn_t)(void *priv, size_t min_size,
     64                                             vpx_codec_frame_buffer_t *fb);
     65 
     66 /*!\brief release frame buffer callback prototype
     67  *
     68  * This callback is invoked by the decoder when the frame buffer is not
     69  * referenced by any other buffers. |fb| is guaranteed to not be NULL. On
     70  * success the callback must return 0. Any failure the callback must return
     71  * a value less than 0.
     72  *
     73  * \param[in] priv         Callback's private data
     74  * \param[in] fb           Pointer to vpx_codec_frame_buffer_t
     75  */
     76 typedef int (*vpx_release_frame_buffer_cb_fn_t)(void *priv,
     77                                                 vpx_codec_frame_buffer_t *fb);
     78 
     79 #ifdef __cplusplus
     80 }  // extern "C"
     81 #endif
     82 
     83 #endif  // VPX_VPX_FRAME_BUFFER_H_
     84