FFmpeg
Variables
adpcm_data.c File Reference
#include <stdint.h>

Go to the source code of this file.

Variables

const int8_t ff_adpcm_index_table [16]
 
const int16_t ff_adpcm_step_table [89]
 This is the step table. More...
 
const int16_t ff_adpcm_AdaptationTable []
 
const uint8_t ff_adpcm_AdaptCoeff1 []
 Divided by 4 to fit in 8-bit integers. More...
 
const int8_t ff_adpcm_AdaptCoeff2 []
 Divided by 4 to fit in 8-bit integers. More...
 
const int16_t ff_adpcm_yamaha_indexscale []
 
const int8_t ff_adpcm_yamaha_difflookup []
 

Detailed Description

ADPCM tables

Definition in file adpcm_data.c.

Variable Documentation

◆ ff_adpcm_index_table

const int8_t ff_adpcm_index_table[16]

◆ ff_adpcm_step_table

const int16_t ff_adpcm_step_table[89]
Initial value:
= {
7, 8, 9, 10, 11, 12, 13, 14, 16, 17,
19, 21, 23, 25, 28, 31, 34, 37, 41, 45,
50, 55, 60, 66, 73, 80, 88, 97, 107, 118,
130, 143, 157, 173, 190, 209, 230, 253, 279, 307,
337, 371, 408, 449, 494, 544, 598, 658, 724, 796,
876, 963, 1060, 1166, 1282, 1411, 1552, 1707, 1878, 2066,
2272, 2499, 2749, 3024, 3327, 3660, 4026, 4428, 4871, 5358,
5894, 6484, 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899,
15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767
}

This is the step table.

Note that many programs use slight deviations from this table, but such deviations are negligible:

Definition at line 39 of file adpcm_data.c.

Referenced by adpcm_compress_trellis(), adpcm_ima_alp_compress_sample(), adpcm_ima_alp_expand_nibble(), adpcm_ima_compress_sample(), adpcm_ima_expand_nibble(), adpcm_ima_mtf_expand_nibble(), adpcm_ima_qt_compress_sample(), adpcm_ima_qt_expand_nibble(), adpcm_ima_wav_expand_nibble(), adpcm_swf_decode(), adpcm_zork_expand_nibble(), decode_frame(), and predict_table_init().

◆ ff_adpcm_AdaptationTable

const int16_t ff_adpcm_AdaptationTable[]
Initial value:
= {
230, 230, 230, 230, 307, 409, 512, 614,
768, 614, 512, 409, 307, 230, 230, 230
}

Definition at line 54 of file adpcm_data.c.

Referenced by adpcm_compress_trellis(), adpcm_ct_expand_nibble(), adpcm_ms_compress_sample(), and adpcm_ms_expand_nibble().

◆ ff_adpcm_AdaptCoeff1

const uint8_t ff_adpcm_AdaptCoeff1[]
Initial value:
= {
64, 128, 0, 48, 60, 115, 98
}

Divided by 4 to fit in 8-bit integers.

Definition at line 60 of file adpcm_data.c.

Referenced by adpcm_decode_frame(), and adpcm_encode_init().

◆ ff_adpcm_AdaptCoeff2

const int8_t ff_adpcm_AdaptCoeff2[]
Initial value:
= {
0, -64, 0, 16, 0, -52, -58
}

Divided by 4 to fit in 8-bit integers.

Definition at line 65 of file adpcm_data.c.

Referenced by adpcm_decode_frame(), and adpcm_encode_init().

◆ ff_adpcm_yamaha_indexscale

const int16_t ff_adpcm_yamaha_indexscale[]
Initial value:
= {
230, 230, 230, 230, 307, 409, 512, 614,
230, 230, 230, 230, 307, 409, 512, 614
}

Definition at line 69 of file adpcm_data.c.

Referenced by adpcm_compress_trellis(), adpcm_yamaha_compress_sample(), and adpcm_yamaha_expand_nibble().

◆ ff_adpcm_yamaha_difflookup

const int8_t ff_adpcm_yamaha_difflookup[]
Initial value:
= {
1, 3, 5, 7, 9, 11, 13, 15,
-1, -3, -5, -7, -9, -11, -13, -15
}

Definition at line 74 of file adpcm_data.c.

Referenced by adpcm_ima_compress_sample(), adpcm_yamaha_compress_sample(), and adpcm_yamaha_expand_nibble().