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

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Detailed Description

Definition of an elementary stream format and its associated API

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Define Documentation

#define MMAL_ES_FORMAT_COMPARE_FLAG_BITRATE   0x04

The bitrate is different

#define MMAL_ES_FORMAT_COMPARE_FLAG_ENCODING   0x02

The encoding is different

#define MMAL_ES_FORMAT_COMPARE_FLAG_ES_OTHER   0x10000000

Other ES specific parameters are different

#define MMAL_ES_FORMAT_COMPARE_FLAG_EXTRADATA   0x10

The extradata is different

#define MMAL_ES_FORMAT_COMPARE_FLAG_FLAGS   0x08

The flags are different

#define MMAL_ES_FORMAT_COMPARE_FLAG_TYPE   0x01

The type is different

#define MMAL_ES_FORMAT_COMPARE_FLAG_VIDEO_ASPECT_RATIO   0x0800

The video aspect ratio is different

#define MMAL_ES_FORMAT_COMPARE_FLAG_VIDEO_COLOR_SPACE   0x1000

The video color space is different

#define MMAL_ES_FORMAT_COMPARE_FLAG_VIDEO_CROPPING   0x0200

The video cropping is different

#define MMAL_ES_FORMAT_COMPARE_FLAG_VIDEO_FRAME_RATE   0x0400

The video frame rate is different

#define MMAL_ES_FORMAT_COMPARE_FLAG_VIDEO_RESOLUTION   0x0100

The video resolution is different

#define MMAL_ES_FORMAT_FLAG_FRAMED   0x1

The elementary stream will already be framed

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Typedef Documentation

typedef struct MMAL_AUDIO_FORMAT_T MMAL_AUDIO_FORMAT_T

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

typedef struct MMAL_ES_FORMAT_T MMAL_ES_FORMAT_T

Definition of an elementary stream format

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Enumeration Type Documentation

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)

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Function Documentation

MMAL_ES_FORMAT_T* mmal_format_alloc

(

void

)

Allocate and initialise a MMAL_ES_FORMAT_T structure.

Returns:

a MMAL_ES_FORMAT_T structure

Allocate a format structure

uint32_t mmal_format_compare	(	MMAL_ES_FORMAT_T *	fmt1,
		MMAL_ES_FORMAT_T *	fmt2
	)

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

Compare 2 format structures

void mmal_format_copy	(	MMAL_ES_FORMAT_T *	fmt_dst,
		MMAL_ES_FORMAT_T *	fmt_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

Copy a format structure

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

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

Free a format structure

MMAL_STATUS_T mmal_format_full_copy	(	MMAL_ES_FORMAT_T *	fmt_dst,
		MMAL_ES_FORMAT_T *	fmt_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

Full copy of a format structure (including extradata)