Elementary stream format

Classes
struct	MMAL_VIDEO_FORMAT_T
struct	MMAL_AUDIO_FORMAT_T
struct	MMAL_SUBPICTURE_FORMAT_T
union	MMAL_ES_SPECIFIC_FORMAT_T
struct	MMAL_ES_FORMAT_T

Typedefs
typedef struct MMAL_AUDIO_FORMAT_T	MMAL_AUDIO_FORMAT_T
typedef struct MMAL_ES_FORMAT_T	MMAL_ES_FORMAT_T

Enumerations
enum	MMAL_ES_TYPE_T {   MMAL_ES_TYPE_UNKNOWN, MMAL_ES_TYPE_CONTROL, MMAL_ES_TYPE_AUDIO, MMAL_ES_TYPE_VIDEO,   MMAL_ES_TYPE_SUBPICTURE }

Functions
MMAL_ES_FORMAT_T *	mmal_format_alloc (void)
void	mmal_format_free (MMAL_ES_FORMAT_T *format)
MMAL_STATUS_T	mmal_format_extradata_alloc (MMAL_ES_FORMAT_T *format, unsigned int size)
void	mmal_format_copy (MMAL_ES_FORMAT_T *format_dest, MMAL_ES_FORMAT_T *format_src)
MMAL_STATUS_T	mmal_format_full_copy (MMAL_ES_FORMAT_T *format_dest, MMAL_ES_FORMAT_T *format_src)
uint32_t	mmal_format_compare (MMAL_ES_FORMAT_T *format_1, MMAL_ES_FORMAT_T *format_2)

Elementary stream flags
The following flags describe properties of an elementary stream
#define	MMAL_ES_FORMAT_FLAG_FRAMED   0x1

Undefined encoding value.
This value indicates an unknown encoding
#define	MMAL_ENCODING_UNKNOWN   0

Default encoding variant value.
This value indicates the default encoding variant is used
#define	MMAL_ENCODING_VARIANT_DEFAULT   0

Comparison flags
The following flags describe the differences between 2 format structures
#define	MMAL_ES_FORMAT_COMPARE_FLAG_TYPE   0x01
#define	MMAL_ES_FORMAT_COMPARE_FLAG_ENCODING   0x02
#define	MMAL_ES_FORMAT_COMPARE_FLAG_BITRATE   0x04
#define	MMAL_ES_FORMAT_COMPARE_FLAG_FLAGS   0x08
#define	MMAL_ES_FORMAT_COMPARE_FLAG_EXTRADATA   0x10
#define	MMAL_ES_FORMAT_COMPARE_FLAG_VIDEO_RESOLUTION   0x0100
#define	MMAL_ES_FORMAT_COMPARE_FLAG_VIDEO_CROPPING   0x0200
#define	MMAL_ES_FORMAT_COMPARE_FLAG_VIDEO_FRAME_RATE   0x0400
#define	MMAL_ES_FORMAT_COMPARE_FLAG_VIDEO_ASPECT_RATIO   0x0800
#define	MMAL_ES_FORMAT_COMPARE_FLAG_VIDEO_COLOR_SPACE   0x1000
#define	MMAL_ES_FORMAT_COMPARE_FLAG_ES_OTHER   0x10000000

Detailed Description

Definition of an elementary stream format and its associated API

Macro Definition Documentation

MMAL_ENCODING_UNKNOWN

#define MMAL_ENCODING_UNKNOWN   0

Definition at line 114 of file mmal_format.h.

MMAL_ENCODING_VARIANT_DEFAULT

#define MMAL_ENCODING_VARIANT_DEFAULT   0

Definition at line 121 of file mmal_format.h.

MMAL_ES_FORMAT_COMPARE_FLAG_BITRATE

#define MMAL_ES_FORMAT_COMPARE_FLAG_BITRATE   0x04

The bitrate is different

Definition at line 194 of file mmal_format.h.

MMAL_ES_FORMAT_COMPARE_FLAG_ENCODING

#define MMAL_ES_FORMAT_COMPARE_FLAG_ENCODING   0x02

The encoding is different

Definition at line 193 of file mmal_format.h.

MMAL_ES_FORMAT_COMPARE_FLAG_ES_OTHER

#define MMAL_ES_FORMAT_COMPARE_FLAG_ES_OTHER   0x10000000

Other ES specific parameters are different

Definition at line 204 of file mmal_format.h.

MMAL_ES_FORMAT_COMPARE_FLAG_EXTRADATA

#define MMAL_ES_FORMAT_COMPARE_FLAG_EXTRADATA   0x10

The extradata is different

Definition at line 196 of file mmal_format.h.

MMAL_ES_FORMAT_COMPARE_FLAG_FLAGS

#define MMAL_ES_FORMAT_COMPARE_FLAG_FLAGS   0x08

The flags are different

Definition at line 195 of file mmal_format.h.

MMAL_ES_FORMAT_COMPARE_FLAG_TYPE

#define MMAL_ES_FORMAT_COMPARE_FLAG_TYPE   0x01

The type is different

Definition at line 192 of file mmal_format.h.

MMAL_ES_FORMAT_COMPARE_FLAG_VIDEO_ASPECT_RATIO

#define MMAL_ES_FORMAT_COMPARE_FLAG_VIDEO_ASPECT_RATIO   0x0800

The video aspect ratio is different

Definition at line 201 of file mmal_format.h.

MMAL_ES_FORMAT_COMPARE_FLAG_VIDEO_COLOR_SPACE

#define MMAL_ES_FORMAT_COMPARE_FLAG_VIDEO_COLOR_SPACE   0x1000

The video color space is different

Definition at line 202 of file mmal_format.h.

MMAL_ES_FORMAT_COMPARE_FLAG_VIDEO_CROPPING

#define MMAL_ES_FORMAT_COMPARE_FLAG_VIDEO_CROPPING   0x0200

The video cropping is different

Definition at line 199 of file mmal_format.h.

MMAL_ES_FORMAT_COMPARE_FLAG_VIDEO_FRAME_RATE

#define MMAL_ES_FORMAT_COMPARE_FLAG_VIDEO_FRAME_RATE   0x0400

The video frame rate is different

Definition at line 200 of file mmal_format.h.

MMAL_ES_FORMAT_COMPARE_FLAG_VIDEO_RESOLUTION

#define MMAL_ES_FORMAT_COMPARE_FLAG_VIDEO_RESOLUTION   0x0100

The video resolution is different

Definition at line 198 of file mmal_format.h.

MMAL_ES_FORMAT_FLAG_FRAMED

#define MMAL_ES_FORMAT_FLAG_FRAMED   0x1

The elementary stream will already be framed

Definition at line 107 of file mmal_format.h.

Typedef Documentation

MMAL_AUDIO_FORMAT_T

typedef struct MMAL_AUDIO_FORMAT_T MMAL_AUDIO_FORMAT_T

Definition of an audio format. This describes the properties specific to an audio stream

MMAL_ES_FORMAT_T

typedef struct MMAL_ES_FORMAT_T MMAL_ES_FORMAT_T

Definition of an elementary stream format

Enumeration Type Documentation

MMAL_ES_TYPE_T

enum MMAL_ES_TYPE_T

Enumeration of the different types of elementary streams. This divides elementary streams into 4 big categories, plus an invalid type.

Enumerator
MMAL_ES_TYPE_UNKNOWN	Unknown elementary stream type
MMAL_ES_TYPE_CONTROL	Elementary stream of control commands
MMAL_ES_TYPE_AUDIO	Audio elementary stream
MMAL_ES_TYPE_VIDEO	Video elementary stream
MMAL_ES_TYPE_SUBPICTURE	Sub-picture elementary stream (e.g. subtitles, overlays)

Definition at line 44 of file mmal_format.h.

Function Documentation

mmal_format_alloc()

MMAL_ES_FORMAT_T* mmal_format_alloc

(

void

)

Allocate and initialise a MMAL_ES_FORMAT_T structure.

Returns

a MMAL_ES_FORMAT_T structure

mmal_format_compare()

uint32_t mmal_format_compare	(	MMAL_ES_FORMAT_T *	format_1,
		MMAL_ES_FORMAT_T *	format_2
	)

Compare 2 format structures and returns a set of flags describing the differences. The result will be zero if the structures are the same, or a combination of one or more of the Comparison flags if different.

Parameters

format_1	first MMAL_ES_FORMAT_T to compare
format_2	second MMAL_ES_FORMAT_T to compare

Returns

set of flags describing the differences

mmal_format_copy()

void mmal_format_copy	(	MMAL_ES_FORMAT_T *	format_dest,
		MMAL_ES_FORMAT_T *	format_src
	)

Shallow copy a format structure. It is worth noting that the extradata buffer will not be copied in the new format.

Parameters

format_dest	destination MMAL_ES_FORMAT_T for the copy
format_src	source MMAL_ES_FORMAT_T for the copy

mmal_format_extradata_alloc()

MMAL_STATUS_T mmal_format_extradata_alloc	(	MMAL_ES_FORMAT_T *	format,
		unsigned int	size
	)

Allocate the extradata buffer in MMAL_ES_FORMAT_T. This buffer will be freed automatically when the format is destroyed or another allocation is done.

Parameters

format	format structure for which the extradata buffer will be allocated
size	size of the extradata buffer to allocate

Returns

MMAL_SUCCESS on success

mmal_format_free()

void mmal_format_free

(

MMAL_ES_FORMAT_T *

format

)

Free a MMAL_ES_FORMAT_T structure allocated by mmal_format_alloc.

Parameters

format

the MMAL_ES_FORMAT_T structure to free

mmal_format_full_copy()

MMAL_STATUS_T mmal_format_full_copy	(	MMAL_ES_FORMAT_T *	format_dest,
		MMAL_ES_FORMAT_T *	format_src
	)

Fully copy a format structure, including the extradata buffer.

Parameters

format_dest	destination MMAL_ES_FORMAT_T for the copy
format_src	source MMAL_ES_FORMAT_T for the copy

Returns

MMAL_SUCCESS on success