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