rational.h File Reference

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Detailed Description

Rational numbers.

Author:

Michael Niedermayer <michaelni@gmx.at>

Definition in file rational.h.

Go to the source code of this file.

Classes
struct	AVRational
	Rational number num/den. More...
Functions
static int	av_cmp_q (AVRational a, AVRational b)
	Compare two rationals.
static double	av_q2d (AVRational a)
	Rational to double conversion.
int	av_reduce (int *dst_nom, int *dst_den, int64_t nom, int64_t den, int64_t max)
	Reduce a fraction.
AVRational	av_mul_q (AVRational b, AVRational c)
	Multiplies two rationals.
AVRational	av_div_q (AVRational b, AVRational c)
	Divides one rational by another.
AVRational	av_add_q (AVRational b, AVRational c)
	Adds two rationals.
AVRational	av_sub_q (AVRational b, AVRational c)
	Subtracts one rational from another.
AVRational	av_d2q (double d, int max)
	Converts a double precision floating point number to a rational.

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Function Documentation

static int av_cmp_q	(	AVRational	a,
		AVRational	b
	)			[inline, static]

Compare two rationals.

Parameters:

	a	first rational
	b	second rational

Returns:

0 if a==b, 1 if a>b and -1 if a<b.

Definition at line 47 of file rational.h.

Referenced by aspect_to_info().

static double av_q2d

(

AVRational

a

)

[inline, static]

Rational to double conversion.

Parameters:

a

rational to convert

Returns:

(double) a

Definition at line 59 of file rational.h.

Referenced by av_find_stream_info(), decode_syncpoint(), dump_stream_format(), dv_write_pack(), ff_rate_control_init(), ff_rate_estimate_qscale(), ff_vbv_update(), flv_write_header(), getFileInfo(), AvFormatDecoder::GetFrame(), grab_read_header(), grabThumbnail(), AvFormatDecoder::H264PreProcessPkt(), init_pass2(), ThumbFinder::initAVCodec(), AvFormatDecoder::InitVideoCodec(), modify_qscale(), mov_write_tkhd_tag(), mpeg1_encode_sequence_header(), MPV_encode_init(), normalized_fps(), read_seek(), thp_read_header(), v4l2_read_header(), write_header(), x11grab_read_header(), and x11grab_read_packet().

int av_reduce	(	int *	dst_nom,
		int *	dst_den,
		int64_t	nom,
		int64_t	den,
		int64_t	max
	)

Reduce a fraction.

This is useful for framerate calculations.

Parameters:

	dst_nom	destination numerator
	dst_den	destination denominator
	nom	source numerator
	den	source denominator
	max	the maximum allowed for dst_nom & dst_den

Returns:

1 if exact, 0 otherwise

Definition at line 35 of file rational.c.

Referenced by asf_read_header(), av_add_q(), av_d2q(), av_find_stream_info(), av_mul_q(), avcodec_string(), MPEG2fixup::BuildFrame(), decode_slice_header(), dxa_read_header(), matroska_read_header(), mpeg_decode_postinit(), smacker_read_header(), vmd_read_header(), yuv4_generate_header(), and yuv4_read_header().

AVRational av_mul_q	(	AVRational	b,
		AVRational	c
	)

Multiplies two rationals.

Parameters:

	b	first rational.
	c	second rational.

Returns:

b*c.

Definition at line 77 of file rational.c.

Referenced by av_div_q(), and mkv_write_tracks().

AVRational av_div_q	(	AVRational	b,
		AVRational	c
	)

Divides one rational by another.

Parameters:

	b	first rational.
	c	second rational.

Returns:

b/c.

Definition at line 82 of file rational.c.

Referenced by mpeg_decode_postinit().

AVRational av_add_q	(	AVRational	b,
		AVRational	c
	)

Adds two rationals.

Parameters:

	b	first rational.
	c	second rational.

Returns:

b+c.

Definition at line 86 of file rational.c.

Referenced by av_sub_q().

AVRational av_sub_q	(	AVRational	b,
		AVRational	c
	)

Subtracts one rational from another.

Parameters:

	b	first rational.
	c	second rational.

Returns:

b-c.

Definition at line 91 of file rational.c.

AVRational av_d2q	(	double	d,
		int	max
	)

Converts a double precision floating point number to a rational.

Parameters:

	d	double to convert
	max	the maximum allowed numerator and denominator

Returns:

(AVRational) d.

Definition at line 95 of file rational.c.

Referenced by av_get_q(), av_opt_set_defaults2(), av_parse_video_frame_rate(), av_set_number(), mpeg_decode_postinit(), nuv_header(), and thp_read_header().