#include <assert.h>
#include <stdint.h>
#include <limits.h>
#include "mathematics.h"
#include "libavutil/common.h"
Go to the source code of this file.
Functions | |
| int64_t | av_gcd (int64_t a, int64_t b) |
| Return the greatest common divisor of a and b. | |
| int64_t | av_rescale_rnd (int64_t a, int64_t b, int64_t c, enum AVRounding rnd) |
| Rescale a 64-bit integer with specified rounding. | |
| int64_t | av_rescale (int64_t a, int64_t b, int64_t c) |
| Rescale a 64-bit integer with rounding to nearest. | |
| int64_t | av_rescale_q (int64_t a, AVRational bq, AVRational cq) |
| Rescale a 64-bit integer by 2 rational numbers. | |
| int | av_compare_ts (int64_t ts_a, AVRational tb_a, int64_t ts_b, AVRational tb_b) |
| Compare 2 timestamps each in its own timebases. | |
| int64_t | av_compare_mod (uint64_t a, uint64_t b, uint64_t mod) |
| Compare 2 integers modulo mod. | |
Variables | |
| const uint8_t | ff_sqrt_tab [256] |
| const uint8_t | ff_log2_tab [256] |
| const uint8_t | av_reverse [256] |
Definition in file mathematics.c.
| int64_t av_compare_mod | ( | uint64_t | a, | |
| uint64_t | b, | |||
| uint64_t | mod | |||
| ) |
Compare 2 integers modulo mod.
That is we compare integers a and b for which only the least significant log2(mod) bits are known.
| mod | must be a power of 2 |
Definition at line 150 of file mathematics.c.
Referenced by av_read_frame().
| int av_compare_ts | ( | int64_t | ts_a, | |
| AVRational | tb_a, | |||
| int64_t | ts_b, | |||
| AVRational | tb_b | |||
| ) |
Compare 2 timestamps each in its own timebases.
The result of the function is undefined if one of the timestamps is outside the int64_t range when represented in the others timebase.
Definition at line 140 of file mathematics.c.
Referenced by ff_gen_syncpoint_search(), ff_interleave_compare_dts(), search_hi_lo_keyframes(), and transcode().
| int64_t av_gcd | ( | int64_t | a, | |
| int64_t | b | |||
| ) |
Return the greatest common divisor of a and b.
If both a and b are 0 or either or both are <0 then behavior is undefined.
Definition at line 73 of file mathematics.c.
Referenced by av_gcd(), av_reduce(), avcodec_string(), avformat_find_stream_info(), config_output(), decode_main_header(), dump_stream_format(), ff_parse_specific_params(), h263_decode_picture_header(), init(), and MPV_encode_init().
| int64_t av_rescale | ( | int64_t | a, | |
| int64_t | b, | |||
| int64_t | c | |||
| ) | const |
Rescale a 64-bit integer with rounding to nearest.
A simple a*b/c isn't possible as it can overflow.
Definition at line 130 of file mathematics.c.
Referenced by asf_build_simple_index(), av_dump_format(), av_estimate_timings_from_bit_rate(), av_gen_search(), av_seek_frame(), av_update_cur_dts(), avi_read_header(), compute_pkt_fields(), compute_pkt_fields2(), config_props(), dc1394_read_header(), finalize_packet(), get_pcr(), mov_build_index(), mov_find_next_sample(), mov_read_trak(), mov_write_tapt_tag(), mp3_parse_vbr_tags(), mpeg_mux_write_packet(), mpegts_write_header(), mpegts_write_packet(), mpegts_write_pes(), mxf_read_seek(), nsv_parse_NSVs_header(), output_packet(), pcm_read_seek(), r3d_read_reda(), and vqf_read_seek().
| int64_t av_rescale_q | ( | int64_t | a, | |
| AVRational | bq, | |||
| AVRational | cq | |||
| ) |
Rescale a 64-bit integer by 2 rational numbers.
Definition at line 134 of file mathematics.c.
Referenced by av_update_stream_timings(), avformat_find_stream_info(), avi_read_packet(), avi_read_seek(), compute_chapters_end(), copy_chapters(), decode_frame(), do_audio_out(), do_subtitle_out(), do_video_out(), dv_extract_video_info(), dv_offset_reset(), dv_read_header(), ff_interleave_new_audio_packet(), ff_write_chained(), fill_all_stream_timings(), get_subtitle_pkt(), http_prepare_data(), main(), mkv_write_chapters(), mov_create_chapter_track(), mov_read_seek(), mov_write_chpl_tag(), mp3_parse_vbr_tags(), ogg_compare_granule(), oggvorbis_encode_frame(), output_packet(), parse_forced_key_frames(), print_report(), read_header(), read_seek2(), rl2_read_seek(), rtcp_send_sr(), rtp_write_header(), rtsp_read_play(), rtsp_read_seek(), seek_subtitle(), source_request_frame(), start_frame(), start_frame_overlay(), transcode(), video_thread(), write_audio_frame(), and write_video_frame().
| int64_t av_rescale_rnd | ( | int64_t | a, | |
| int64_t | b, | |||
| int64_t | c, | |||
| enum | AVRounding | |||
| ) | const |
Rescale a 64-bit integer with specified rounding.
A simple a*b/c isn't possible as it can overflow.
Definition at line 78 of file mathematics.c.
Referenced by applehttp_read_seek(), av_compare_ts(), av_nearer_q(), av_rescale(), av_rescale_q(), av_rescale_rnd(), compute_pkt_fields(), dv_write_pack(), ff_nut_reset_ts(), gxf_compare_field_nb(), gxf_write_media_preamble(), mov_write_edts_tag(), mov_write_mvhd_tag(), mov_write_tkhd_tag(), pcm_read_seek(), read_seek2(), rtmp_read_seek(), rtp_write_header(), vp8_init(), vqf_read_seek(), and write_packet().
| const uint8_t av_reverse[256] |
Initial value:
{
0x00,0x80,0x40,0xC0,0x20,0xA0,0x60,0xE0,0x10,0x90,0x50,0xD0,0x30,0xB0,0x70,0xF0,
0x08,0x88,0x48,0xC8,0x28,0xA8,0x68,0xE8,0x18,0x98,0x58,0xD8,0x38,0xB8,0x78,0xF8,
0x04,0x84,0x44,0xC4,0x24,0xA4,0x64,0xE4,0x14,0x94,0x54,0xD4,0x34,0xB4,0x74,0xF4,
0x0C,0x8C,0x4C,0xCC,0x2C,0xAC,0x6C,0xEC,0x1C,0x9C,0x5C,0xDC,0x3C,0xBC,0x7C,0xFC,
0x02,0x82,0x42,0xC2,0x22,0xA2,0x62,0xE2,0x12,0x92,0x52,0xD2,0x32,0xB2,0x72,0xF2,
0x0A,0x8A,0x4A,0xCA,0x2A,0xAA,0x6A,0xEA,0x1A,0x9A,0x5A,0xDA,0x3A,0xBA,0x7A,0xFA,
0x06,0x86,0x46,0xC6,0x26,0xA6,0x66,0xE6,0x16,0x96,0x56,0xD6,0x36,0xB6,0x76,0xF6,
0x0E,0x8E,0x4E,0xCE,0x2E,0xAE,0x6E,0xEE,0x1E,0x9E,0x5E,0xDE,0x3E,0xBE,0x7E,0xFE,
0x01,0x81,0x41,0xC1,0x21,0xA1,0x61,0xE1,0x11,0x91,0x51,0xD1,0x31,0xB1,0x71,0xF1,
0x09,0x89,0x49,0xC9,0x29,0xA9,0x69,0xE9,0x19,0x99,0x59,0xD9,0x39,0xB9,0x79,0xF9,
0x05,0x85,0x45,0xC5,0x25,0xA5,0x65,0xE5,0x15,0x95,0x55,0xD5,0x35,0xB5,0x75,0xF5,
0x0D,0x8D,0x4D,0xCD,0x2D,0xAD,0x6D,0xED,0x1D,0x9D,0x5D,0xDD,0x3D,0xBD,0x7D,0xFD,
0x03,0x83,0x43,0xC3,0x23,0xA3,0x63,0xE3,0x13,0x93,0x53,0xD3,0x33,0xB3,0x73,0xF3,
0x0B,0x8B,0x4B,0xCB,0x2B,0xAB,0x6B,0xEB,0x1B,0x9B,0x5B,0xDB,0x3B,0xBB,0x7B,0xFB,
0x07,0x87,0x47,0xC7,0x27,0xA7,0x67,0xE7,0x17,0x97,0x57,0xD7,0x37,0xB7,0x77,0xF7,
0x0F,0x8F,0x4F,0xCF,0x2F,0xAF,0x6F,0xEF,0x1F,0x9F,0x5F,0xDF,0x3F,0xBF,0x7F,0xFF,
}
Definition at line 54 of file mathematics.c.
Referenced by asv2_get_bits(), asv2_put_bits(), bitswap_32(), decode_frame(), inv_bits(), ir2_decode_frame(), pcm_decode_frame(), pcm_encode_frame(), s302m_decode_frame(), tiff_unpack_strip(), and wnv1_get_code().
| const uint8_t ff_log2_tab[256] |
Initial value:
{
0,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7
}
Definition at line 43 of file mathematics.c.
Referenced by av_log2_16bit_c(), av_log2_c(), ebml_read_num(), ff_ps_read_data(), put_xsub_rle(), and seq_decode_op1().
| const uint8_t ff_sqrt_tab[256] |
Initial value:
{
0, 16, 23, 28, 32, 36, 40, 43, 46, 48, 51, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 77, 79, 80, 82, 84, 85, 87, 88, 90,
91, 92, 94, 95, 96, 98, 99,100,102,103,104,105,107,108,109,110,111,112,114,115,116,117,118,119,120,121,122,123,124,125,126,127,
128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,144,144,145,146,147,148,149,150,151,151,152,153,154,155,156,156,
157,158,159,160,160,161,162,163,164,164,165,166,167,168,168,169,170,171,171,172,173,174,174,175,176,176,177,178,179,179,180,181,
182,182,183,184,184,185,186,186,187,188,188,189,190,190,191,192,192,193,194,194,195,196,196,197,198,198,199,200,200,201,202,202,
203,204,204,205,205,206,207,207,208,208,209,210,210,211,212,212,213,213,214,215,215,216,216,217,218,218,219,219,220,220,221,222,
222,223,223,224,224,225,226,226,227,227,228,228,229,230,230,231,231,232,232,233,233,234,235,235,236,236,237,237,238,238,239,239,
240,240,241,242,242,243,243,244,244,245,245,246,246,247,247,248,248,249,249,250,250,251,251,252,252,253,253,254,254,255,255,255
}
Definition at line 32 of file mathematics.c.
Referenced by ff_sqrt().
1.5.8