libavutil/mathematics.h File Reference

#include <stdint.h>
#include <math.h>
#include "common.h"
#include "rational.h"

Go to the source code of this file.

Defines
#define	M_E   2.7182818284590452354
#define	M_LN2   0.69314718055994530942
#define	M_LN10   2.30258509299404568402
#define	M_PI   3.14159265358979323846
#define	M_SQRT1_2   0.70710678118654752440
Enumerations
enum	AVRounding {   AV_ROUND_ZERO = 0, AV_ROUND_INF = 1, AV_ROUND_DOWN = 2, AV_ROUND_UP = 3,   AV_ROUND_NEAR_INF = 5 }
Functions
int64_t av_const	av_gcd (int64_t a, int64_t b)
int64_t	av_rescale (int64_t a, int64_t b, int64_t c) av_const
	Rescales a 64-bit integer with rounding to nearest.
int64_t	av_rescale_rnd (int64_t a, int64_t b, int64_t c, enum AVRounding) av_const
	Rescales a 64-bit integer with specified rounding.
int64_t	av_rescale_q (int64_t a, AVRational bq, AVRational cq) av_const
	Rescales a 64-bit integer by 2 rational numbers.

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Define Documentation

#define M_E   2.7182818284590452354

Definition at line 30 of file mathematics.h.

Referenced by get_qscale(), and Process().

#define M_LN10   2.30258509299404568402

Definition at line 36 of file mathematics.h.

Referenced by ff_acelp_decode_gain_code().

#define M_LN2   0.69314718055994530942

Definition at line 33 of file mathematics.h.

Referenced by encode_block(), and encode_init().

#define M_PI   3.14159265358979323846

Definition at line 39 of file mathematics.h.

Referenced by AC3_encode_init(), audio_encode_example(), av_build_filter(), build_basis(), decode_init(), eval_expr(), ff_fft_init(), ff_iir_filter_init_coeffs(), ff_kbd_window_init(), ff_mdct_init(), ff_rdft_init(), ff_ref_dct_init(), ff_sine_window_init(), fft_init(), fft_ref_init(), get_qscale(), idct248_ref(), imc_decode_init(), imdct_ref(), init_atrac3_transforms(), lsp2polyf(), mdct_ref(), open_audio(), Process(), qdm2_fft_generate_tone(), qdm2_fft_tone_synthesizer(), vorbis_floor0_decode(), and wma_lsp_to_curve_init().

#define M_SQRT1_2   0.70710678118654752440

Definition at line 42 of file mathematics.h.

Referenced by dca_subsubframe(), and nelly_decode_block().

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Enumeration Type Documentation

enum AVRounding

Enumerator:

AV_ROUND_ZERO	Round toward zero.
AV_ROUND_INF	Round away from zero.
AV_ROUND_DOWN	Round toward -infinity.
AV_ROUND_UP	Round toward +infinity.
AV_ROUND_NEAR_INF	Round to nearest and halfway cases away from zero.

Definition at line 45 of file mathematics.h.

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Function Documentation

int64_t av_const av_gcd	(	int64_t	a,
		int64_t	b
	)

Definition at line 53 of file mathematics.c.

Referenced by av_find_stream_info(), av_gcd(), av_reduce(), av_set_pts_info(), avcodec_string(), decode_main_header(), dump_stream_format(), ff_gcd(), ff_parse_specific_params(), h263_decode_picture_header(), mov_read_ctts(), mov_read_elst(), mov_read_stts(), MPV_encode_init(), and xvid_correct_framerate().

int64_t av_rescale	(	int64_t	a,
		int64_t	b,
		int64_t	c
	)			const

Rescales a 64-bit integer with rounding to nearest.

A simple a*b/c isn't possible as it can overflow.

Definition at line 116 of file mathematics.c.

Referenced by asf_build_simple_index(), av_estimate_timings_from_bit_rate(), av_gen_search(), av_seek_frame(), av_update_cur_dts(), avi_read_header(), avi_read_packet(), avi_read_seek(), compute_pkt_fields(), compute_pkt_fields2(), dc1394_read_common(), dump_format(), finalize_packet(), mov_read_packet(), mov_read_trak(), mpeg_mux_write_packet(), mpegts_write_packet(), mxf_read_seek(), nsv_parse_NSVs_header(), output_packet(), and r3d_read_reda().

int64_t av_rescale_q	(	int64_t	a,
		AVRational	bq,
		AVRational	cq
	)			const

Rescales a 64-bit integer by 2 rational numbers.

Definition at line 120 of file mathematics.c.

Referenced by av_encode(), av_find_stream_info(), av_update_stream_timings(), compute_chapters_end(), decode_thread(), do_audio_out(), do_subtitle_out(), do_video_out(), dv_extract_video_info(), dv_offset_reset(), dv_read_header(), ff_interleave_new_audio_packet(), fill_all_stream_timings(), http_prepare_data(), main(), mov_read_seek(), mp3_parse_vbr_tags(), ogg_compare_granule(), oggvorbis_encode_frame(), output_packet(), rl2_read_seek(), rtcp_send_sr(), rtp_write_header(), rtsp_read_seek(), write_audio_frame(), and write_video_frame().

int64_t av_rescale_rnd	(	int64_t	a,
		int64_t	b,
		int64_t	c,
		enum	AVRounding
	)			const

Rescales a 64-bit integer with specified rounding.

A simple a*b/c isn't possible as it can overflow.

Definition at line 64 of file mathematics.c.

Referenced by av_nearer_q(), av_rescale(), av_rescale_q(), av_rescale_rnd(), dv_write_pack(), ff_nut_reset_ts(), gxf_write_media_preamble(), mov_write_edts_tag(), mov_write_mvhd_tag(), mov_write_tkhd_tag(), rtp_write_header(), and write_packet().