1/* 2 * LucasArts VIMA decoder 3 * Copyright (c) 2012 Paul B Mahol 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * FFmpeg is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with FFmpeg; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22/** 23 * @file 24 * LucasArts VIMA audio decoder 25 * @author Paul B Mahol 26 */ 27 28#include "libavutil/channel_layout.h" 29 30#include "adpcm_data.h" 31#include "avcodec.h" 32#include "get_bits.h" 33#include "internal.h" 34 35static int predict_table_init = 0; 36static uint16_t predict_table[5786 * 2]; 37 38static const uint8_t size_table[] = { 39 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 40 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 41 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 42 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 43 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 44 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7 45}; 46 47static const int8_t index_table1[] = { 48 -1, 4, -1, 4 49}; 50 51static const int8_t index_table2[] = { 52 -1, -1, 2, 6, -1, -1, 2, 6 53}; 54 55static const int8_t index_table3[] = { 56 -1, -1, -1, -1, 1, 2, 4, 6, -1, -1, -1, -1, 1, 2, 4, 6 57}; 58 59static const int8_t index_table4[] = { 60 -1, -1, -1, -1, -1, -1, -1, -1, 1, 1, 1, 2, 2, 4, 5, 6, 61 -1, -1, -1, -1, -1, -1, -1, -1, 1, 1, 1, 2, 2, 4, 5, 6 62}; 63 64static const int8_t index_table5[] = { 65 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 66 1, 1, 1, 1, 1, 2, 2, 2, 2, 4, 4, 4, 5, 5, 6, 6, 67 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 68 1, 1, 1, 1, 1, 2, 2, 2, 2, 4, 4, 4, 5, 5, 6, 6 69}; 70 71static const int8_t index_table6[] = { 72 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 73 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 74 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 75 2, 2, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6, 76 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 77 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 78 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 79 2, 2, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6 80}; 81 82static const int8_t *const step_index_tables[] = { 83 index_table1, index_table2, index_table3, 84 index_table4, index_table5, index_table6 85}; 86 87static av_cold int decode_init(AVCodecContext *avctx) 88{ 89 int start_pos; 90 91 avctx->sample_fmt = AV_SAMPLE_FMT_S16; 92 93 if (predict_table_init) 94 return 0; 95 96 for (start_pos = 0; start_pos < 64; start_pos++) { 97 unsigned int dest_pos, table_pos; 98 99 for (table_pos = 0, dest_pos = start_pos; 100 table_pos < FF_ARRAY_ELEMS(ff_adpcm_step_table); 101 table_pos++, dest_pos += 64) { 102 int put = 0, count, table_value; 103 104 table_value = ff_adpcm_step_table[table_pos]; 105 for (count = 32; count != 0; count >>= 1) { 106 if (start_pos & count) 107 put += table_value; 108 table_value >>= 1; 109 } 110 predict_table[dest_pos] = put; 111 } 112 } 113 predict_table_init = 1; 114 115 return 0; 116} 117 118static int decode_frame(AVCodecContext *avctx, void *data, 119 int *got_frame_ptr, AVPacket *pkt) 120{ 121 GetBitContext gb; 122 AVFrame *frame = data; 123 int16_t pcm_data[2]; 124 uint32_t samples; 125 int8_t channel_hint[2]; 126 int ret, chan; 127 int channels = 1; 128 129 if (pkt->size < 13) 130 return AVERROR_INVALIDDATA; 131 132 if ((ret = init_get_bits8(&gb, pkt->data, pkt->size)) < 0) 133 return ret; 134 135 samples = get_bits_long(&gb, 32); 136 if (samples == 0xffffffff) { 137 skip_bits_long(&gb, 32); 138 samples = get_bits_long(&gb, 32); 139 } 140 141 if (samples > pkt->size * 2) 142 return AVERROR_INVALIDDATA; 143 144 channel_hint[0] = get_sbits(&gb, 8); 145 if (channel_hint[0] & 0x80) { 146 channel_hint[0] = ~channel_hint[0]; 147 channels = 2; 148 } 149 avctx->channels = channels; 150 avctx->channel_layout = (channels == 2) ? AV_CH_LAYOUT_STEREO 151 : AV_CH_LAYOUT_MONO; 152 pcm_data[0] = get_sbits(&gb, 16); 153 if (channels > 1) { 154 channel_hint[1] = get_sbits(&gb, 8); 155 pcm_data[1] = get_sbits(&gb, 16); 156 } 157 158 frame->nb_samples = samples; 159 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) 160 return ret; 161 162 for (chan = 0; chan < channels; chan++) { 163 uint16_t *dest = (uint16_t *)frame->data[0] + chan; 164 int step_index = channel_hint[chan]; 165 int output = pcm_data[chan]; 166 int sample; 167 168 for (sample = 0; sample < samples; sample++) { 169 int lookup_size, lookup, highbit, lowbits; 170 171 step_index = av_clip(step_index, 0, 88); 172 lookup_size = size_table[step_index]; 173 lookup = get_bits(&gb, lookup_size); 174 highbit = 1 << (lookup_size - 1); 175 lowbits = highbit - 1; 176 177 if (lookup & highbit) 178 lookup ^= highbit; 179 else 180 highbit = 0; 181 182 if (lookup == lowbits) { 183 output = get_sbits(&gb, 16); 184 } else { 185 int predict_index, diff; 186 187 predict_index = (lookup << (7 - lookup_size)) | (step_index << 6); 188 predict_index = av_clip(predict_index, 0, 5785); 189 diff = predict_table[predict_index]; 190 if (lookup) 191 diff += ff_adpcm_step_table[step_index] >> (lookup_size - 1); 192 if (highbit) 193 diff = -diff; 194 195 output = av_clip_int16(output + diff); 196 } 197 198 *dest = output; 199 dest += channels; 200 201 step_index += step_index_tables[lookup_size - 2][lookup]; 202 } 203 } 204 205 *got_frame_ptr = 1; 206 207 return pkt->size; 208} 209 210AVCodec ff_adpcm_vima_decoder = { 211 .name = "adpcm_vima", 212 .long_name = NULL_IF_CONFIG_SMALL("LucasArts VIMA audio"), 213 .type = AVMEDIA_TYPE_AUDIO, 214 .id = AV_CODEC_ID_ADPCM_VIMA, 215 .init = decode_init, 216 .decode = decode_frame, 217 .capabilities = CODEC_CAP_DR1, 218}; 219 220AVCodec ff_vima_decoder = { 221 .name = "vima", 222 .long_name = NULL_IF_CONFIG_SMALL("LucasArts VIMA audio"), 223 .type = AVMEDIA_TYPE_AUDIO, 224 .id = AV_CODEC_ID_ADPCM_VIMA, 225 .init = decode_init, 226 .decode = decode_frame, 227 .capabilities = CODEC_CAP_DR1, 228}; 229