xref: /third_party/ffmpeg/libavcodec/vima.c (revision cabdff1a) 
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
37static uint16_t predict_table[5786 * 2];
38
39static 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
48static const int8_t index_table1[] = {
49    -1, 4, -1, 4
50};
51
52static const int8_t index_table2[] = {
53    -1, -1, 2, 6, -1, -1, 2, 6
54};
55
56static const int8_t index_table3[] = {
57    -1, -1, -1, -1, 1, 2, 4, 6, -1, -1, -1, -1, 1, 2, 4, 6
58};
59
60static 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
65static 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
72static 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
83static const int8_t *const step_index_tables[] = {
84    index_table1, index_table2, index_table3,
85    index_table4, index_table5, index_table6
86};
87
88static 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
109static 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
120static 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
210const 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