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.
 */
#ifdef __cplusplus
extern "C" {
#endif

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

    /*!\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*/


#endif
#ifdef __cplusplus
}
#endif