Common Algorithm Interface

Data Structures
struct	vpx_codec_ctx
	Codec context structure. More...
Modules
	External Memory Allocation Functions
	Decoder Algorithm Interface
	Encoder Algorithm Interface
Files
file	vpx_codec.h
	Describes the codec algorithm interface to applications.
Defines
#define	DEPRECATED
	Decorator indicating a function is deprecated.
#define	DECLSPEC_DEPRECATED
#define	UNUSED
	Decorator indicating a function is potentially unused.
#define	VPX_CODEC_ABI_VERSION
	Current ABI version number.
#define	VPX_CODEC_CAP_DECODER   0x1
#define	VPX_CODEC_CAP_ENCODER   0x2
#define	VPX_CODEC_CAP_XMA   0x4
#define	VPX_CODEC_USE_XMA   0x00000001
#define	VPX_VERSION_MAJOR(v)   ((v>>16)&0xff)
#define	VPX_VERSION_MINOR(v)   ((v>>8)&0xff)
#define	VPX_VERSION_PATCH(v)   ((v>>0)&0xff)
#define	vpx_codec_version_major()   ((vpx_codec_version()>>16)&0xff)
	Return the version major number.
#define	vpx_codec_version_minor()   ((vpx_codec_version()>>8)&0xff)
	Return the version minor number.
#define	vpx_codec_version_patch()   ((vpx_codec_version()>>0)&0xff)
	Return the version patch number.
#define	vpx_codec_control(ctx, id, data)
	vpx_codec_control wrapper macro
#define	VPX_CTRL_USE_TYPE(id, typ)
	vpx_codec_control type definition macro
#define	VPX_CTRL_USE_TYPE_DEPRECATED(id, typ)
	vpx_codec_control deprecated type definition macro
#define	VPX_CTRL_VOID(id)
	vpx_codec_control void type definition macro
Typedefs
typedef long	vpx_codec_caps_t
	Codec capabilities bitfield.
typedef long	vpx_codec_flags_t
	Initialization-time Feature Enabling.
typedef struct vpx_codec_iface	vpx_codec_iface_t
	Codec interface structure.
typedef struct vpx_codec_priv	vpx_codec_priv_t
	Codec private data structure.
typedef const void *	vpx_codec_iter_t
	Iterator.
typedef struct vpx_codec_ctx	vpx_codec_ctx_t
	Codec context structure.
Enumerations
enum	vpx_codec_err_t {   VPX_CODEC_OK, VPX_CODEC_ERROR, VPX_CODEC_MEM_ERROR, VPX_CODEC_ABI_MISMATCH,   VPX_CODEC_INCAPABLE, VPX_CODEC_UNSUP_BITSTREAM, VPX_CODEC_UNSUP_FEATURE, VPX_CODEC_CORRUPT_FRAME,   VPX_CODEC_INVALID_PARAM, VPX_CODEC_LIST_END }
	Algorithm return codes. More...
Functions
int	vpx_codec_version (void)
	Return the version information (as an integer).
const char *	vpx_codec_version_str (void)
	Return the version information (as a string).
const char *	vpx_codec_version_extra_str (void)
	Return the version information (as a string).
const char *	vpx_codec_build_config (void)
	Return the build configuration.
const char *	vpx_codec_iface_name (vpx_codec_iface_t *iface)
	Return the name for a given interface.
const char *	vpx_codec_err_to_string (vpx_codec_err_t err)
	Convert error number to printable string.
const char *	vpx_codec_error (vpx_codec_ctx_t *ctx)
	Retrieve error synopsis for codec context.
const char *	vpx_codec_error_detail (vpx_codec_ctx_t *ctx)
	Retrieve detailed error information for codec context.
vpx_codec_err_t	vpx_codec_destroy (vpx_codec_ctx_t *ctx)
	Destroy a codec instance.
vpx_codec_caps_t	vpx_codec_get_caps (vpx_codec_iface_t *iface)
	Get the capabilities of an algorithm.
vpx_codec_err_t	vpx_codec_control_ (vpx_codec_ctx_t *ctx, int ctrl_id,...)
	Control algorithm.

---

Detailed Description

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).

---

Define Documentation

#define DECLSPEC_DEPRECATED

Decorator indicating a function is deprecated.

#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

#define VPX_CODEC_USE_XMA   0x00000001

Use eXternal Memory Allocation mode

#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

#define vpx_codec_control	(	ctx,
		id,
		data		)

vpx_codec_control wrapper macro

This macro allows for type safe conversions across the variadic parameter to vpx_codec_control_().

#define VPX_CTRL_USE_TYPE	(	id,
		typ		)

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.

#define VPX_CTRL_USE_TYPE_DEPRECATED	(	id,
		typ		)

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.

#define VPX_CTRL_VOID

(

id

)

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.

---

Typedef Documentation

typedef long vpx_codec_caps_t

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_flags_t

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 struct vpx_codec_iface vpx_codec_iface_t

Codec interface structure.

Contains function pointers and other data private to the codec implementation. This structure is opaque to the application.

typedef struct vpx_codec_priv vpx_codec_priv_t

Codec private data structure.

Contains data private to the codec implementation. This structure is opaque to the application.

typedef const void* vpx_codec_iter_t

Iterator.

Opaque storage used for iterating over lists.

typedef struct vpx_codec_ctx vpx_codec_ctx_t

Codec context structure.

All codecs 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.

---

Enumeration Type Documentation

enum vpx_codec_err_t

Algorithm return codes.

Enumerator:

VPX_CODEC_OK	Operation completed without error.
VPX_CODEC_ERROR	Unspecified error.
VPX_CODEC_MEM_ERROR	Memory operation failed.
VPX_CODEC_ABI_MISMATCH	ABI version mismatch.
VPX_CODEC_INCAPABLE	Algorithm does not have required capability.
VPX_CODEC_UNSUP_BITSTREAM	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 SHOULD be treated as fatal to the stream.
VPX_CODEC_UNSUP_FEATURE	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 MAY be treated as fatal to the stream or MAY be treated as fatal to the current GOP.
VPX_CODEC_CORRUPT_FRAME	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 MAY be treated as fatal to the stream or MAY be treated as fatal to the current GOP. If decoding is continued for the current GOP, artifacts may be present.
VPX_CODEC_INVALID_PARAM	An application-supplied parameter is not valid.
VPX_CODEC_LIST_END	An iterator reached the end of list.

---

Function Documentation

int vpx_codec_version

(

void

)

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.

const char* vpx_codec_version_str

(

void

)

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_extra_str

(

void

)

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_build_config

(

void

)

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_iface_name

(

vpx_codec_iface_t *

iface

)

Return the name for a given interface.

Returns a human readable string for name of the given codec interface.

Parameters:

[in]

iface

Interface pointer

const char* vpx_codec_err_to_string

(

vpx_codec_err_t

err

)

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.

Parameters:

[in]

err

Error number.

const char* vpx_codec_error

(

vpx_codec_ctx_t *

ctx

)

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.

Parameters:

[in]

ctx

Pointer to this instance's context.

const char* vpx_codec_error_detail

(

vpx_codec_ctx_t *

ctx

)

Retrieve detailed error information for codec context.

Returns a human readable string providing detailed information about the last error.

Parameters:

[in]

ctx

Pointer to this instance's context.

Return values:

NULL

No detailed information is available.

vpx_codec_err_t vpx_codec_destroy

(

vpx_codec_ctx_t *

ctx

)

Destroy a codec instance.

Destroys a codec context, freeing any associated memory buffers.

Parameters:

[in]

ctx

Pointer to this instance's context

Return values:

	VPX_CODEC_OK	The codec algorithm initialized.
	VPX_CODEC_MEM_ERROR	Memory allocation failed.

vpx_codec_caps_t vpx_codec_get_caps

(

vpx_codec_iface_t *

iface

)

Get the capabilities of an algorithm.

Retrieves the capabilities bitfield from the algorithm's interface.

Parameters:

[in]

iface

Pointer to the algorithm interface

vpx_codec_err_t vpx_codec_control_	(	vpx_codec_ctx_t *	ctx,
		int	ctrl_id,
			...
	)

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.

Parameters:

[in]	ctx	Pointer to this instance's context
[in]	ctrl_id	Algorithm specific control identifier

Return values:

	VPX_CODEC_OK	The control request was processed.
	VPX_CODEC_ERROR	The control request was not processed.
	VPX_CODEC_INVALID_PARAM	The data was not valid.