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