2 * Copyright (c) 2010 The WebM project authors. All Rights Reserved.
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.
10 #ifndef VPX_VPX_DECODER_H_
11 #define VPX_VPX_DECODER_H_
13 /*!\defgroup decoder Decoder Algorithm Interface
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.
22 * \brief Describes the decoder algorithm interface to applications.
24 * This file describes the interface between an application and a
25 * video decoder algorithm.
32 #include "./vpx_codec.h"
33 #include "./vpx_frame_buffer.h"
35 /*!\brief Current ABI version number
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
43 #define VPX_DECODER_ABI_VERSION \
44 (3 + VPX_CODEC_ABI_VERSION) /**<\hideinitializer*/
46 /*! \brief Decoder capabilities bitfield
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.
52 * The available flags are specified by VPX_CODEC_CAP_* defines.
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
62 /*! \brief Initialization-time Feature Enabling
64 * Certain codec features must be known at initialization time, to allow for
65 * proper memory allocation.
67 * The available flags are specified by VPX_CODEC_USE_* defines.
69 /*!\brief Can support frame-based multi-threading */
70 #define VPX_CODEC_CAP_FRAME_THREADING 0x200000
71 /*!brief Can support external frame buffers */
72 #define VPX_CODEC_CAP_EXTERNAL_FRAME_BUFFER 0x400000
74 #define VPX_CODEC_USE_POSTPROC 0x10000 /**< Postprocess decoded frame */
75 /*!\brief Conceal errors in decoded frames */
76 #define VPX_CODEC_USE_ERROR_CONCEALMENT 0x20000
77 /*!\brief The input frame should be passed to the decoder one fragment at a
79 #define VPX_CODEC_USE_INPUT_FRAGMENTS 0x40000
80 /*!\brief Enable frame-based multi-threading */
81 #define VPX_CODEC_USE_FRAME_THREADING 0x80000
83 /*!\brief Stream properties
85 * This structure is used to query or set properties of the decoded
86 * stream. Algorithms may extend this structure with data specific
87 * to their bitstream by setting the sz member appropriately.
89 typedef struct vpx_codec_stream_info {
90 unsigned int sz; /**< Size of this structure */
91 unsigned int w; /**< Width (or 0 for unknown/default) */
92 unsigned int h; /**< Height (or 0 for unknown/default) */
93 unsigned int is_kf; /**< Current frame is a keyframe */
94 } vpx_codec_stream_info_t;
98 * The following functions are required to be implemented for all decoders.
99 * They represent the base case functionality expected of all decoders.
102 /*!\brief Initialization Configurations
104 * This structure is used to pass init time configuration options to the
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 */
113 /*!\brief Initialize a decoder instance
115 * Initializes a decoder context using the given interface. Applications
116 * should call the vpx_codec_dec_init convenience macro instead of this
117 * function directly, to ensure that the ABI version number parameter
118 * is properly initialized.
120 * If the library was configured with --disable-multithread, this call
121 * is not thread safe and should be guarded with a lock if being used
122 * in a multithreaded context.
124 * \param[in] ctx Pointer to this instance's context.
125 * \param[in] iface Pointer to the algorithm interface to use.
126 * \param[in] cfg Configuration to use, if known. May be NULL.
127 * \param[in] flags Bitfield of VPX_CODEC_USE_* flags
128 * \param[in] ver ABI version number. Must be set to
129 * VPX_DECODER_ABI_VERSION
130 * \retval #VPX_CODEC_OK
131 * The decoder algorithm initialized.
132 * \retval #VPX_CODEC_MEM_ERROR
133 * Memory allocation failed.
135 vpx_codec_err_t vpx_codec_dec_init_ver(vpx_codec_ctx_t *ctx,
136 vpx_codec_iface_t *iface,
137 const vpx_codec_dec_cfg_t *cfg,
138 vpx_codec_flags_t flags, int ver);
140 /*!\brief Convenience macro for vpx_codec_dec_init_ver()
142 * Ensures the ABI version parameter is properly set.
144 #define vpx_codec_dec_init(ctx, iface, cfg, flags) \
145 vpx_codec_dec_init_ver(ctx, iface, cfg, flags, VPX_DECODER_ABI_VERSION)
147 /*!\brief Parse stream info from a buffer
149 * Performs high level parsing of the bitstream. Construction of a decoder
150 * context is not necessary. Can be used to determine if the bitstream is
151 * of the proper format, and to extract information from the stream.
153 * \param[in] iface Pointer to the algorithm interface
154 * \param[in] data Pointer to a block of data to parse
155 * \param[in] data_sz Size of the data buffer
156 * \param[in,out] si Pointer to stream info to update. The size member
157 * \ref MUST be properly initialized, but \ref MAY be
158 * clobbered by the algorithm. This parameter \ref MAY
161 * \retval #VPX_CODEC_OK
162 * Bitstream is parsable and stream information updated
164 vpx_codec_err_t vpx_codec_peek_stream_info(vpx_codec_iface_t *iface,
166 unsigned int data_sz,
167 vpx_codec_stream_info_t *si);
169 /*!\brief Return information about the current stream.
171 * Returns information about the stream that has been parsed during decoding.
173 * \param[in] ctx Pointer to this instance's context
174 * \param[in,out] si Pointer to stream info to update. The size member
175 * \ref MUST be properly initialized, but \ref MAY be
176 * clobbered by the algorithm. This parameter \ref MAY
179 * \retval #VPX_CODEC_OK
180 * Bitstream is parsable and stream information updated
182 vpx_codec_err_t vpx_codec_get_stream_info(vpx_codec_ctx_t *ctx,
183 vpx_codec_stream_info_t *si);
185 /*!\brief Decode data
187 * Processes a buffer of coded data. If the processing results in a new
188 * decoded frame becoming available, PUT_SLICE and PUT_FRAME events may be
189 * generated, as appropriate. Encoded data \ref MUST be passed in DTS (decode
190 * time stamp) order. Frames produced will always be in PTS (presentation
192 * If the decoder is configured with VPX_CODEC_USE_INPUT_FRAGMENTS enabled,
193 * data and data_sz can contain a fragment of the encoded frame. Fragment
194 * \#n must contain at least partition \#n, but can also contain subsequent
195 * partitions (\#n+1 - \#n+i), and if so, fragments \#n+1, .., \#n+i must
196 * be empty. When no more data is available, this function should be called
197 * with NULL as data and 0 as data_sz. The memory passed to this function
198 * must be available until the frame has been decoded.
200 * \param[in] ctx Pointer to this instance's context
201 * \param[in] data Pointer to this block of new coded data. If
202 * NULL, a VPX_CODEC_CB_PUT_FRAME event is posted
203 * for the previously decoded frame.
204 * \param[in] data_sz Size of the coded data, in bytes.
205 * \param[in] user_priv Application specific data to associate with
207 * \param[in] deadline Soft deadline the decoder should attempt to meet,
208 * in us. Set to zero for unlimited.
210 * \return Returns #VPX_CODEC_OK if the coded data was processed completely
211 * and future pictures can be decoded without error. Otherwise,
212 * see the descriptions of the other error codes in ::vpx_codec_err_t
213 * for recoverability capabilities.
215 vpx_codec_err_t vpx_codec_decode(vpx_codec_ctx_t *ctx, const uint8_t *data,
216 unsigned int data_sz, void *user_priv,
219 /*!\brief Decoded frames iterator
221 * Iterates over a list of the frames available for display. The iterator
222 * storage should be initialized to NULL to start the iteration. Iteration is
223 * complete when this function returns NULL.
225 * The list of available frames becomes valid upon completion of the
226 * vpx_codec_decode call, and remains valid until the next call to
229 * \param[in] ctx Pointer to this instance's context
230 * \param[in,out] iter Iterator storage, initialized to NULL
232 * \return Returns a pointer to an image, if one is ready for display. Frames
233 * produced will always be in PTS (presentation time stamp) order.
235 vpx_image_t *vpx_codec_get_frame(vpx_codec_ctx_t *ctx, vpx_codec_iter_t *iter);
237 /*!\defgroup cap_put_frame Frame-Based Decoding Functions
239 * The following functions are required to be implemented for all decoders
240 * that advertise the VPX_CODEC_CAP_PUT_FRAME capability. Calling these
242 * for codecs that don't advertise this capability will result in an error
243 * code being returned, usually VPX_CODEC_ERROR
247 /*!\brief put frame callback prototype
249 * This callback is invoked by the decoder to notify the application of
250 * the availability of decoded image data.
252 typedef void (*vpx_codec_put_frame_cb_fn_t)(void *user_priv,
253 const vpx_image_t *img);
255 /*!\brief Register for notification of frame completion.
257 * Registers a given function to be called when a decoded frame is
260 * \param[in] ctx Pointer to this instance's context
261 * \param[in] cb Pointer to the callback function
262 * \param[in] user_priv User's private data
264 * \retval #VPX_CODEC_OK
265 * Callback successfully registered.
266 * \retval #VPX_CODEC_ERROR
267 * Decoder context not initialized, or algorithm not capable of
268 * posting slice completion.
270 vpx_codec_err_t vpx_codec_register_put_frame_cb(vpx_codec_ctx_t *ctx,
271 vpx_codec_put_frame_cb_fn_t cb,
274 /*!@} - end defgroup cap_put_frame */
276 /*!\defgroup cap_put_slice Slice-Based Decoding Functions
278 * The following functions are required to be implemented for all decoders
279 * that advertise the VPX_CODEC_CAP_PUT_SLICE capability. Calling these
281 * for codecs that don't advertise this capability will result in an error
282 * code being returned, usually VPX_CODEC_ERROR
286 /*!\brief put slice callback prototype
288 * This callback is invoked by the decoder to notify the application of
289 * the availability of partially decoded image data. The
291 typedef void (*vpx_codec_put_slice_cb_fn_t)(void *user_priv,
292 const vpx_image_t *img,
293 const vpx_image_rect_t *valid,
294 const vpx_image_rect_t *update);
296 /*!\brief Register for notification of slice completion.
298 * Registers a given function to be called when a decoded slice is
301 * \param[in] ctx Pointer to this instance's context
302 * \param[in] cb Pointer to the callback function
303 * \param[in] user_priv User's private data
305 * \retval #VPX_CODEC_OK
306 * Callback successfully registered.
307 * \retval #VPX_CODEC_ERROR
308 * Decoder context not initialized, or algorithm not capable of
309 * posting slice completion.
311 vpx_codec_err_t vpx_codec_register_put_slice_cb(vpx_codec_ctx_t *ctx,
312 vpx_codec_put_slice_cb_fn_t cb,
315 /*!@} - end defgroup cap_put_slice*/
317 /*!\defgroup cap_external_frame_buffer External Frame Buffer Functions
319 * The following section is required to be implemented for all decoders
320 * that advertise the VPX_CODEC_CAP_EXTERNAL_FRAME_BUFFER capability.
321 * Calling this function for codecs that don't advertise this capability
322 * will result in an error code being returned, usually VPX_CODEC_ERROR.
325 * Currently this only works with VP9.
329 /*!\brief Pass in external frame buffers for the decoder to use.
331 * Registers functions to be called when libvpx needs a frame buffer
332 * to decode the current frame and a function to be called when libvpx does
333 * not internally reference the frame buffer. This set function must
334 * be called before the first call to decode or libvpx will assume the
335 * default behavior of allocating frame buffers internally.
337 * \param[in] ctx Pointer to this instance's context
338 * \param[in] cb_get Pointer to the get callback function
339 * \param[in] cb_release Pointer to the release callback function
340 * \param[in] cb_priv Callback's private data
342 * \retval #VPX_CODEC_OK
343 * External frame buffers will be used by libvpx.
344 * \retval #VPX_CODEC_INVALID_PARAM
345 * One or more of the callbacks were NULL.
346 * \retval #VPX_CODEC_ERROR
347 * Decoder context not initialized, or algorithm not capable of
348 * using external frame buffers.
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
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);
359 /*!@} - end defgroup cap_external_frame_buffer */
361 /*!@} - end defgroup decoder*/
365 #endif // VPX_VPX_DECODER_H_