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