vpx/vpx_codec.h

/*
 *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */


/*!\defgroup codec Common Algorithm Interface
 * This abstraction allows applications to easily support multiple video
 * formats with minimal code duplication. This section describes the interface
 * common to all codecs (both encoders and decoders).
 * @{
 */

/*!\file
 * \brief Describes the codec algorithm interface to applications.
 *
 * This file describes the interface between an application and a
 * video codec algorithm.
 *
 * An application instantiates a specific codec instance by using
 * vpx_codec_init() and a pointer to the algorithm's interface structure:
 *     <pre>
 *     my_app.c:
 *       extern vpx_codec_iface_t my_codec;
 *       {
 *           vpx_codec_ctx_t algo;
 *           res = vpx_codec_init(&algo, &my_codec);
 *       }
 *     </pre>
 *
 * Once initialized, the instance is manged using other functions from
 * the vpx_codec_* family.
 */
#ifndef VPX_VPX_CODEC_H_
#define VPX_VPX_CODEC_H_

#ifdef __cplusplus
extern "C" {
#endif

#include "./vpx_integer.h"
#include "./vpx_image.h"

  /*!\brief Decorator indicating a function is deprecated */
#ifndef DEPRECATED
#if defined(__GNUC__) && __GNUC__
#define DEPRECATED          __attribute__ ((deprecated))
#elif defined(_MSC_VER)
#define DEPRECATED
#else
#define DEPRECATED
#endif
#endif  /* DEPRECATED */

#ifndef DECLSPEC_DEPRECATED
#if defined(__GNUC__) && __GNUC__
#define DECLSPEC_DEPRECATED /**< \copydoc #DEPRECATED */
#elif defined(_MSC_VER)
#define DECLSPEC_DEPRECATED __declspec(deprecated) /**< \copydoc #DEPRECATED */
#else
#define DECLSPEC_DEPRECATED /**< \copydoc #DEPRECATED */
#endif
#endif  /* DECLSPEC_DEPRECATED */

  /*!\brief Decorator indicating a function is potentially unused */
#ifdef UNUSED
#elif __GNUC__
#define UNUSED __attribute__ ((unused))
#else
#define UNUSED
#endif

  /*!\brief Current ABI version number
   *
   * \internal
   * If this file is altered in any way that changes the ABI, this value
   * must be bumped.  Examples include, but are not limited to, changing
   * types, removing or reassigning enums, adding/removing/rearranging
   * fields to structures
   */
#define VPX_CODEC_ABI_VERSION (2 + VPX_IMAGE_ABI_VERSION) /**<\hideinitializer*/

  /*!\brief Algorithm return codes */
  typedef enum {
    /*!\brief Operation completed without error */
    VPX_CODEC_OK,

    /*!\brief Unspecified error */
    VPX_CODEC_ERROR,

    /*!\brief Memory operation failed */
    VPX_CODEC_MEM_ERROR,

    /*!\brief ABI version mismatch */
    VPX_CODEC_ABI_MISMATCH,

    /*!\brief Algorithm does not have required capability */
    VPX_CODEC_INCAPABLE,

    /*!\brief The given bitstream is not supported.
     *
     * The bitstream was unable to be parsed at the highest level. The decoder
     * is unable to proceed. This error \ref SHOULD be treated as fatal to the
     * stream. */
    VPX_CODEC_UNSUP_BITSTREAM,

    /*!\brief Encoded bitstream uses an unsupported feature
     *
     * The decoder does not implement a feature required by the encoder. This
     * return code should only be used for features that prevent future
     * pictures from being properly decoded. This error \ref MAY be treated as
     * fatal to the stream or \ref MAY be treated as fatal to the current GOP.
     */
    VPX_CODEC_UNSUP_FEATURE,

    /*!\brief The coded data for this stream is corrupt or incomplete
     *
     * There was a problem decoding the current frame.  This return code
     * should only be used for failures that prevent future pictures from
     * being properly decoded. This error \ref MAY be treated as fatal to the
     * stream or \ref MAY be treated as fatal to the current GOP. If decoding
     * is continued for the current GOP, artifacts may be present.
     */
    VPX_CODEC_CORRUPT_FRAME,

    /*!\brief An application-supplied parameter is not valid.
     *
     */
    VPX_CODEC_INVALID_PARAM,

    /*!\brief An iterator reached the end of list.
     *
     */
    VPX_CODEC_LIST_END

  }
  vpx_codec_err_t;


  /*! \brief Codec capabilities bitfield
   *
   *  Each codec advertises the capabilities it supports as part of its
   *  ::vpx_codec_iface_t interface structure. Capabilities are extra interfaces
   *  or functionality, and are not required to be supported.
   *
   *  The available flags are specified by VPX_CODEC_CAP_* defines.
   */
  typedef long vpx_codec_caps_t;
#define VPX_CODEC_CAP_DECODER 0x1 /**< Is a decoder */
#define VPX_CODEC_CAP_ENCODER 0x2 /**< Is an encoder */
#define VPX_CODEC_CAP_XMA     0x4 /**< Supports eXternal Memory Allocation */


  /*! \brief Initialization-time Feature Enabling
   *
   *  Certain codec features must be known at initialization time, to allow for
   *  proper memory allocation.
   *
   *  The available flags are specified by VPX_CODEC_USE_* defines.
   */
  typedef long vpx_codec_flags_t;
#define VPX_CODEC_USE_XMA 0x00000001    /**< Use eXternal Memory Allocation mode */


  /*!\brief Codec interface structure.
   *
   * Contains function pointers and other data private to the codec
   * implementation. This structure is opaque to the application.
   */
  typedef const struct vpx_codec_iface vpx_codec_iface_t;


  /*!\brief Codec private data structure.
   *
   * Contains data private to the codec implementation. This structure is opaque
   * to the application.
   */
  typedef       struct vpx_codec_priv  vpx_codec_priv_t;


  /*!\brief Iterator
   *
   * Opaque storage used for iterating over lists.
   */
  typedef const void *vpx_codec_iter_t;


  /*!\brief Codec context structure
   *
   * All codecs \ref MUST support this context structure fully. In general,
   * this data should be considered private to the codec algorithm, and
   * not be manipulated or examined by the calling application. Applications
   * may reference the 'name' member to get a printable description of the
   * algorithm.
   */
  typedef struct vpx_codec_ctx {
    const char              *name;        /**< Printable interface name */
    vpx_codec_iface_t       *iface;       /**< Interface pointers */
    vpx_codec_err_t          err;         /**< Last returned error */
    const char              *err_detail;  /**< Detailed info, if available */
    vpx_codec_flags_t        init_flags;  /**< Flags passed at init time */
    union {
      struct vpx_codec_dec_cfg  *dec;   /**< Decoder Configuration Pointer */
      struct vpx_codec_enc_cfg  *enc;   /**< Encoder Configuration Pointer */
      void                      *raw;
    }                        config;      /**< Configuration pointer aliasing union */
    vpx_codec_priv_t        *priv;        /**< Algorithm private storage */
  } vpx_codec_ctx_t;


  /*
   * Library Version Number Interface
   *
   * For example, see the following sample return values:
   *     vpx_codec_version()           (1<<16 | 2<<8 | 3)
   *     vpx_codec_version_str()       "v1.2.3-rc1-16-gec6a1ba"
   *     vpx_codec_version_extra_str() "rc1-16-gec6a1ba"
   */

  /*!\brief Return the version information (as an integer)
   *
   * Returns a packed encoding of the library version number. This will only include
   * the major.minor.patch component of the version number. Note that this encoded
   * value should be accessed through the macros provided, as the encoding may change
   * in the future.
   *
   */
  int vpx_codec_version(void);
#define VPX_VERSION_MAJOR(v) ((v>>16)&0xff) /**< extract major from packed version */
#define VPX_VERSION_MINOR(v) ((v>>8)&0xff)  /**< extract minor from packed version */
#define VPX_VERSION_PATCH(v) ((v>>0)&0xff)  /**< extract patch from packed version */

  /*!\brief Return the version major number */
#define vpx_codec_version_major() ((vpx_codec_version()>>16)&0xff)

  /*!\brief Return the version minor number */
#define vpx_codec_version_minor() ((vpx_codec_version()>>8)&0xff)

  /*!\brief Return the version patch number */
#define vpx_codec_version_patch() ((vpx_codec_version()>>0)&0xff)


  /*!\brief Return the version information (as a string)
   *
   * Returns a printable string containing the full library version number. This may
   * contain additional text following the three digit version number, as to indicate
   * release candidates, prerelease versions, etc.
   *
   */
  const char *vpx_codec_version_str(void);


  /*!\brief Return the version information (as a string)
   *
   * Returns a printable "extra string". This is the component of the string returned
   * by vpx_codec_version_str() following the three digit version number.
   *
   */
  const char *vpx_codec_version_extra_str(void);


  /*!\brief Return the build configuration
   *
   * Returns a printable string containing an encoded version of the build
   * configuration. This may be useful to vpx support.
   *
   */
  const char *vpx_codec_build_config(void);


  /*!\brief Return the name for a given interface
   *
   * Returns a human readable string for name of the given codec interface.
   *
   * \param[in]    iface     Interface pointer
   *
   */
  const char *vpx_codec_iface_name(vpx_codec_iface_t *iface);


  /*!\brief Convert error number to printable string
   *
   * Returns a human readable string for the last error returned by the
   * algorithm. The returned error will be one line and will not contain
   * any newline characters.
   *
   *
   * \param[in]    err     Error number.
   *
   */
  const char *vpx_codec_err_to_string(vpx_codec_err_t  err);


  /*!\brief Retrieve error synopsis for codec context
   *
   * Returns a human readable string for the last error returned by the
   * algorithm. The returned error will be one line and will not contain
   * any newline characters.
   *
   *
   * \param[in]    ctx     Pointer to this instance's context.
   *
   */
  const char *vpx_codec_error(vpx_codec_ctx_t  *ctx);


  /*!\brief Retrieve detailed error information for codec context
   *
   * Returns a human readable string providing detailed information about
   * the last error.
   *
   * \param[in]    ctx     Pointer to this instance's context.
   *
   * \retval NULL
   *     No detailed information is available.
   */
  const char *vpx_codec_error_detail(vpx_codec_ctx_t  *ctx);


  /* REQUIRED FUNCTIONS
   *
   * The following functions are required to be implemented for all codecs.
   * They represent the base case functionality expected of all codecs.
   */

  /*!\brief Destroy a codec instance
   *
   * Destroys a codec context, freeing any associated memory buffers.
   *
   * \param[in] ctx   Pointer to this instance's context
   *
   * \retval #VPX_CODEC_OK
   *     The codec algorithm initialized.
   * \retval #VPX_CODEC_MEM_ERROR
   *     Memory allocation failed.
   */
  vpx_codec_err_t vpx_codec_destroy(vpx_codec_ctx_t *ctx);


  /*!\brief Get the capabilities of an algorithm.
   *
   * Retrieves the capabilities bitfield from the algorithm's interface.
   *
   * \param[in] iface   Pointer to the algorithm interface
   *
   */
  vpx_codec_caps_t vpx_codec_get_caps(vpx_codec_iface_t *iface);


  /*!\brief Control algorithm
   *
   * This function is used to exchange algorithm specific data with the codec
   * instance. This can be used to implement features specific to a particular
   * algorithm.
   *
   * This wrapper function dispatches the request to the helper function
   * associated with the given ctrl_id. It tries to call this function
   * transparently, but will return #VPX_CODEC_ERROR if the request could not
   * be dispatched.
   *
   * Note that this function should not be used directly. Call the
   * #vpx_codec_control wrapper macro instead.
   *
   * \param[in]     ctx              Pointer to this instance's context
   * \param[in]     ctrl_id          Algorithm specific control identifier
   *
   * \retval #VPX_CODEC_OK
   *     The control request was processed.
   * \retval #VPX_CODEC_ERROR
   *     The control request was not processed.
   * \retval #VPX_CODEC_INVALID_PARAM
   *     The data was not valid.
   */
  vpx_codec_err_t vpx_codec_control_(vpx_codec_ctx_t  *ctx,
                                     int               ctrl_id,
                                     ...);
#if defined(VPX_DISABLE_CTRL_TYPECHECKS) && VPX_DISABLE_CTRL_TYPECHECKS
#    define vpx_codec_control(ctx,id,data) vpx_codec_control_(ctx,id,data)
#    define VPX_CTRL_USE_TYPE(id, typ)
#    define VPX_CTRL_USE_TYPE_DEPRECATED(id, typ)
#    define VPX_CTRL_VOID(id, typ)

#else
  /*!\brief vpx_codec_control wrapper macro
   *
   * This macro allows for type safe conversions across the variadic parameter
   * to vpx_codec_control_().
   *
   * \internal
   * It works by dispatching the call to the control function through a wrapper
   * function named with the id parameter.
   */
#    define vpx_codec_control(ctx,id,data) vpx_codec_control_##id(ctx,id,data)\
  /**<\hideinitializer*/


  /*!\brief vpx_codec_control type definition macro
   *
   * This macro allows for type safe conversions across the variadic parameter
   * to vpx_codec_control_(). It defines the type of the argument for a given
   * control identifier.
   *
   * \internal
   * It defines a static function with
   * the correctly typed arguments as a wrapper to the type-unsafe internal
   * function.
   */
#    define VPX_CTRL_USE_TYPE(id, typ) \
  static vpx_codec_err_t \
  vpx_codec_control_##id(vpx_codec_ctx_t*, int, typ) UNUSED;\
  \
  static vpx_codec_err_t \
  vpx_codec_control_##id(vpx_codec_ctx_t  *ctx, int ctrl_id, typ data) {\
    return vpx_codec_control_(ctx, ctrl_id, data);\
  } /**<\hideinitializer*/


  /*!\brief vpx_codec_control deprecated type definition macro
   *
   * Like #VPX_CTRL_USE_TYPE, but indicates that the specified control is
   * deprecated and should not be used. Consult the documentation for your
   * codec for more information.
   *
   * \internal
   * It defines a static function with the correctly typed arguments as a
   * wrapper to the type-unsafe internal function.
   */
#    define VPX_CTRL_USE_TYPE_DEPRECATED(id, typ) \
  DECLSPEC_DEPRECATED static vpx_codec_err_t \
  vpx_codec_control_##id(vpx_codec_ctx_t*, int, typ) DEPRECATED UNUSED;\
  \
  DECLSPEC_DEPRECATED static vpx_codec_err_t \
  vpx_codec_control_##id(vpx_codec_ctx_t  *ctx, int ctrl_id, typ data) {\
    return vpx_codec_control_(ctx, ctrl_id, data);\
  } /**<\hideinitializer*/


  /*!\brief vpx_codec_control void type definition macro
   *
   * This macro allows for type safe conversions across the variadic parameter
   * to vpx_codec_control_(). It indicates that a given control identifier takes
   * no argument.
   *
   * \internal
   * It defines a static function without a data argument as a wrapper to the
   * type-unsafe internal function.
   */
#    define VPX_CTRL_VOID(id) \
  static vpx_codec_err_t \
  vpx_codec_control_##id(vpx_codec_ctx_t*, int) UNUSED;\
  \
  static vpx_codec_err_t \
  vpx_codec_control_##id(vpx_codec_ctx_t  *ctx, int ctrl_id) {\
    return vpx_codec_control_(ctx, ctrl_id);\
  } /**<\hideinitializer*/


#endif


  /*!\defgroup cap_xma External Memory Allocation Functions
   *
   * The following functions are required to be implemented for all codecs
   * that advertise the VPX_CODEC_CAP_XMA capability. Calling these functions
   * for codecs that don't advertise this capability will result in an error
   * code being returned, usually VPX_CODEC_INCAPABLE
   * @{
   */


  /*!\brief Memory Map Entry
   *
   * This structure is used to contain the properties of a memory segment. It
   * is populated by the codec in the request phase, and by the calling
   * application once the requested allocation has been performed.
   */
  typedef struct vpx_codec_mmap {
    /*
     * The following members are set by the codec when requesting a segment
     */
    unsigned int   id;     /**< identifier for the segment's contents */
    unsigned long  sz;     /**< size of the segment, in bytes */
    unsigned int   align;  /**< required alignment of the segment, in bytes */
    unsigned int   flags;  /**< bitfield containing segment properties */
#define VPX_CODEC_MEM_ZERO     0x1  /**< Segment must be zeroed by allocation */
#define VPX_CODEC_MEM_WRONLY   0x2  /**< Segment need not be readable */
#define VPX_CODEC_MEM_FAST     0x4  /**< Place in fast memory, if available */

    /* The following members are to be filled in by the allocation function */
    void          *base;   /**< pointer to the allocated segment */
    void (*dtor)(struct vpx_codec_mmap *map);         /**< destructor to call */
    void          *priv;   /**< allocator private storage */
  } vpx_codec_mmap_t; /**< alias for struct vpx_codec_mmap */


  /*!\brief Iterate over the list of segments to allocate.
   *
   * Iterates over a list of the segments to allocate. The iterator storage
   * should be initialized to NULL to start the iteration. Iteration is complete
   * when this function returns VPX_CODEC_LIST_END. The amount of memory needed to
   * allocate is dependent upon the size of the encoded stream. In cases where the
   * stream is not available at allocation time, a fixed size must be requested.
   * The codec will not be able to operate on streams larger than the size used at
   * allocation time.
   *
   * \param[in]      ctx     Pointer to this instance's context.
   * \param[out]     mmap    Pointer to the memory map entry to populate.
   * \param[in,out]  iter    Iterator storage, initialized to NULL
   *
   * \retval #VPX_CODEC_OK
   *     The memory map entry was populated.
   * \retval #VPX_CODEC_ERROR
   *     Codec does not support XMA mode.
   * \retval #VPX_CODEC_MEM_ERROR
   *     Unable to determine segment size from stream info.
   */
  vpx_codec_err_t vpx_codec_get_mem_map(vpx_codec_ctx_t                *ctx,
                                        vpx_codec_mmap_t               *mmap,
                                        vpx_codec_iter_t               *iter);


  /*!\brief Identify allocated segments to codec instance
   *
   * Stores a list of allocated segments in the codec. Segments \ref MUST be
   * passed in the order they are read from vpx_codec_get_mem_map(), but may be
   * passed in groups of any size. Segments \ref MUST be set only once. The
   * allocation function \ref MUST ensure that the vpx_codec_mmap_t::base member
   * is non-NULL. If the segment requires cleanup handling (e.g., calling free()
   * or close()) then the vpx_codec_mmap_t::dtor member \ref MUST be populated.
   *
   * \param[in]      ctx     Pointer to this instance's context.
   * \param[in]      mmaps   Pointer to the first memory map entry in the list.
   * \param[in]      num_maps  Number of entries being set at this time
   *
   * \retval #VPX_CODEC_OK
   *     The segment was stored in the codec context.
   * \retval #VPX_CODEC_INCAPABLE
   *     Codec does not support XMA mode.
   * \retval #VPX_CODEC_MEM_ERROR
   *     Segment base address was not set, or segment was already stored.

   */
  vpx_codec_err_t  vpx_codec_set_mem_map(vpx_codec_ctx_t   *ctx,
                                         vpx_codec_mmap_t  *mmaps,
                                         unsigned int       num_maps);

  /*!@} - end defgroup cap_xma*/
  /*!@} - end defgroup codec*/
#ifdef __cplusplus
}
#endif
#endif  // VPX_VPX_CODEC_H_