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 #include "libavutil/thread.h"
30
31 #include "adpcm_data.h"
32 #include "avcodec.h"
33 #include "codec_internal.h"
34 #include "get_bits.h"
35 #include "internal.h"
36
37 static uint16_t predict_table[5786 * 2];
38
39 static const uint8_t size_table[] = {
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 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
43 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
44 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
45 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7
46 };
47
48 static const int8_t index_table1[] = {
49 -1, 4, -1, 4
50 };
51
52 static const int8_t index_table2[] = {
53 -1, -1, 2, 6, -1, -1, 2, 6
54 };
55
56 static const int8_t index_table3[] = {
57 -1, -1, -1, -1, 1, 2, 4, 6, -1, -1, -1, -1, 1, 2, 4, 6
58 };
59
60 static const int8_t index_table4[] = {
61 -1, -1, -1, -1, -1, -1, -1, -1, 1, 1, 1, 2, 2, 4, 5, 6,
62 -1, -1, -1, -1, -1, -1, -1, -1, 1, 1, 1, 2, 2, 4, 5, 6
63 };
64
65 static const int8_t index_table5[] = {
66 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
67 1, 1, 1, 1, 1, 2, 2, 2, 2, 4, 4, 4, 5, 5, 6, 6,
68 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
69 1, 1, 1, 1, 1, 2, 2, 2, 2, 4, 4, 4, 5, 5, 6, 6
70 };
71
72 static const int8_t index_table6[] = {
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, -1, -1, -1, -1, -1, -1,
75 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2,
76 2, 2, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6,
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, -1, -1, -1, -1, -1, -1,
79 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2,
80 2, 2, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6
81 };
82
83 static const int8_t *const step_index_tables[] = {
84 index_table1, index_table2, index_table3,
85 index_table4, index_table5, index_table6
86 };
87
predict_table_init(void)88 static av_cold void predict_table_init(void)
89 {
90 for (int start_pos = 0; start_pos < 64; start_pos++) {
91 unsigned int dest_pos, table_pos;
92
93 for (table_pos = 0, dest_pos = start_pos;
94 table_pos < FF_ARRAY_ELEMS(ff_adpcm_step_table);
95 table_pos++, dest_pos += 64) {
96 int put = 0, count, table_value;
97
98 table_value = ff_adpcm_step_table[table_pos];
99 for (count = 32; count != 0; count >>= 1) {
100 if (start_pos & count)
101 put += table_value;
102 table_value >>= 1;
103 }
104 predict_table[dest_pos] = put;
105 }
106 }
107 }
108
decode_init(AVCodecContext * avctx)109 static av_cold int decode_init(AVCodecContext *avctx)
110 {
111 static AVOnce init_static_once = AV_ONCE_INIT;
112
113 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
114
115 ff_thread_once(&init_static_once, predict_table_init);
116
117 return 0;
118 }
119
decode_frame(AVCodecContext * avctx,AVFrame * frame,int * got_frame_ptr,AVPacket * pkt)120 static int decode_frame(AVCodecContext *avctx, AVFrame *frame,
121 int *got_frame_ptr, AVPacket *pkt)
122 {
123 GetBitContext gb;
124 int16_t pcm_data[2];
125 uint32_t samples;
126 int8_t channel_hint[2];
127 int ret, chan;
128 int channels = 1;
129
130 if (pkt->size < 13)
131 return AVERROR_INVALIDDATA;
132
133 if ((ret = init_get_bits8(&gb, pkt->data, pkt->size)) < 0)
134 return ret;
135
136 samples = get_bits_long(&gb, 32);
137 if (samples == 0xffffffff) {
138 skip_bits_long(&gb, 32);
139 samples = get_bits_long(&gb, 32);
140 }
141
142 if (samples > pkt->size * 2)
143 return AVERROR_INVALIDDATA;
144
145 channel_hint[0] = get_sbits(&gb, 8);
146 if (channel_hint[0] & 0x80) {
147 channel_hint[0] = ~channel_hint[0];
148 channels = 2;
149 }
150 av_channel_layout_uninit(&avctx->ch_layout);
151 av_channel_layout_default(&avctx->ch_layout, channels);
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
210 const FFCodec ff_adpcm_vima_decoder = {
211 .p.name = "adpcm_vima",
212 .p.long_name = NULL_IF_CONFIG_SMALL("LucasArts VIMA audio"),
213 .p.type = AVMEDIA_TYPE_AUDIO,
214 .p.id = AV_CODEC_ID_ADPCM_VIMA,
215 .init = decode_init,
216 FF_CODEC_DECODE_CB(decode_frame),
217 .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF,
218 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
219 };
220