BTimeCode¶

Constructor and Destructor¶

BTimeCode()

BTimeCode::BTimeCode()
BTimeCode::BTimeCode(bigtime_t us, timecode_type type = B_TIMECODE_DEFAULT)
BTimeCode::BTimeCode(int hours, int minutes, int seconds, int frames, timecode_type type = B_TIMECODE_DEFAULT)
BTimeCode::BTimeCode(const BTimeCode &clone)

The constructor prepares the BTimeCode object for use. If you use the first form of the constructor, without arguments, you’ll have to call an appropriate function to set the BTimeCode’s time information before using it for translation purposes. This can be done by calling one or more of SetData(), SetType(), SetMicroseconds(), or SetLinearFrames().

The second form of the constructor accepts as input a time in microseconds, us, and the timecode type.

The third form accepts as input a time in hours, minutes, seconds, and frames, as well as the timecode type.

The fourth form of the constructor duplicates an existing BTimeCode object.

~BTimeCode()

BTimeCode::~BTimeCode()

A typical destructor

Member Functions¶

GetData(), SetData()

void BTimeCode::GetData(int *outHours, int *outMinutes, int *outSeconds, int *outFrames, timecode_type *outType)

void BTimeCode::SetData(int hours, int minutes, int seconds, int frames)

GetData() returns the timecode’s value in hours, minutes, seconds, and frames, and also returns the timecode type, if you specify a valid pointer for outType. SetData() lets you set the timecode’s value.

GetString()

void BTimeCode::GetString(char *str) const

Fills str, which must be at least 24 bytes long, with a string indicating the current time in hours, minutes, seconds, and frames. The string is formatted in a manner appropriate to the timecode type. A typical example would be “01:24:09.18”, which is 1 hour, 24 minutes, 9 seconds, and 18 frames.

Hours(), Minutes(), Seconds(), Frames()

void BTimeCode::Hours() const

void BTimeCode::Minutes() const

void BTimeCode::Seconds() const

void BTimeCode::Frames() const

These functions return the time’s hours, minutes, seconds, and frames portions.

LinearFrames(), SetLinearFrames()

int32 BTimeCode::LinearFrames() const

void BTimeCode::SetLinearFrames(int32 linearFrames)

LinearFrames() returns the BTimeCode object’s time in linear frames. SetLinearFrames() lets you change the time, specifying the new time in linear frames.

LinearFrames(), SetMicroseconds()

bigtime_t BTimeCode::LinearFrames() const

void BTimeCode::SetMicroseconds(bigtime_t us)

Microseconds() returns the BTimeCode object’s time, in microseconds. SetMicroseconds() lets you change the time, specifying the new time in microseconds.

Type(), SetType()

timecode_type BTimeCode::Type() const

status_t BTimeCode::SetType(timecode_type type)

Type() returns the BTimeCode object’s timecode type. SetType() lets you change the timecode type.

Return Code	Description
`B_OK`	The type was returned safely.
`B_ERROR`	The timecode type specified is invalid.

Operators¶

BTimeCode &operator=(const BTimeCode &clone)

Makes the current BTimeCode identical to the BTimeCode object specified

BTimeCode &operator==(const BTimeCode &other)

Determines whether or not the two BTimeCode objects are equal (their times are the same, regardless of their timecode types).

BTimeCode &operator<(const BTimeCode &other)

Indicates whether or not one BTimeCode’s time, in microseconds, is less than the other’s.

BTimeCode &operator+=(const BTimeCode &other)

Adds the time of the BTimeCode object other to the current BTimeCode’s time.

BTimeCode &operator-=(const BTimeCode &other)

Subtracts the time of the BTimeCode object other from the current BTimeCode’s time.

BTimeCode &operator+(const BTimeCode &other)

Adds two BTimeCode values together, returning a new BTimeCode.

BTimeCode &operator<(const BTimeCode &other)

Subtracts two BTimeCode values, returning a new one.

Global C Functions¶

count_timecodes()

status_t count_timecodes()

Returns the number of recognized time code types.

frames_to_timecode(), timecode_to_frames()

status_t frames_to_timecode(int32 linearFrames, int *hours, int *minutes, int *seconds, int *frames, const timecode_info code = NULL)

status_t timecode_to_frames(int hours, int minutes, int seconds, int frames, const timecode_info code = NULL)

frames_to_timecode() converts the frame offset linearFrames into hours, minutes, seconds, and frames.

timecode_to_frames() converts the time from hours, minutes, seconds, and frames into a linear frame offset, storing the result in linearFrames.

The timecode_info structure code is used to determine how the conversion should be made, if you specify it. Otherwise B_TIMECODE_DEFAULT is assumed.

Currently these functions always return B_OK, but you should still check for errors because you’d hate it if your app broke in the future, wouldn’t you?

get_timecode_description()

status_t get_timecode_description(timecode_type type, timecode_info *outTimeCode)

Fills out the timecode_info structure specified by outTimeCode with information describing the specified timecode type.

Return Code	Description
`B_OK`	No error.
`B_ERROR`	The specified timecode type isn’t valid.

us_to_timecode(), timecode_to_us()

status_t us_to_timecode(bigtime_t micros, int *hours, int *minutes, int *seconds, int *frames, const timecode_info code = NULL)

status_t timecode_to_us(int hours, int minutes, int seconds, int frames, bigtime_t *micros, const timecode_info code = NULL)

us_to_timecode() converts the time micros, which is specified in microseconds, into hours, minutes, seconds, and frames.

timecode_to_us() converts the time from hours, minutes, seconds, and frames into microseconds, storing the result in micros.

The timecode_info structure code is used to determine how the conversion should be made, if you specify it. Otherwise B_TIMECODE_DEFAULT is assumed.

Currently these functions always return B_OK, but you should still check for errors because you’d hate it if your app broke in the future, wouldn’t you?

Constants¶

timecode_type¶

Declared in: media/TimeCode.h

Constant	Description
`B_TIMECODE_DEFAULT`	The default time code
`B_TIMECODE_100`	100 frames per second.
`B_TIMECODE_75`	CD audio
`B_TIMECODE_30`	MIDI
`B_TIMECODE_30_DROP_2`	NTSC
`B_TIMECODE_30_DROP_4`	Brazil
`B_TIMECODE_25`	PAL
`B_TIMECODE_24`	Film
`B_TIMECODE_18`	Super8

Constants identifying the various timecode types supported by BTimeCode.

Defined Types¶

timecode_info¶

Declared in: media/TimeCode.h

struct timecode_info {
    timecode_type type;
    int drop_frames;
    int every_nth;
    int except_nth;
    int fps_div;
    char name[32];
    char format[32];
    char _reserved_[64];
};

The timecode_info structure describes the attributes of a timecode type. You probably should just use the BTimeCode class, or the global C functions, though. It just makes your life easier.

Field	Description
type	Indicates the timecode type described by the structure.
drop_frames	Indicates how many frames this timecode drops every every_nth minute, except_nth minute.
fps_div	Indicates the nominal frame rate of the format.
name	Is a printable name that can be used in constructing user interfaces.
format	Is a format to be used in calling sprintf(); it’s used by `GetString()`.