vpx/vpx_frame_buffer.h

   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)(
  64     void *priv, size_t min_size, 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)(
  77     void *priv, vpx_codec_frame_buffer_t *fb);
  78
  79 #ifdef __cplusplus
  80 }  // extern "C"
  81 #endif
  82
  83 #endif  // VPX_VPX_FRAME_BUFFER_H_