FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavcodec/vima.c
Date: 2025-10-28 01:11:23
Exec Total Coverage
Lines: 67 79 84.8%
Functions: 3 3 100.0%
Branches: 28 40 70.0%
Line Branch Exec Source
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.h"
32 #include "adpcm_data.h"
33 #include "avcodec.h"
34 #include "codec_internal.h"
35 #include "decode.h"
36 #include "get_bits.h"
37
38 static uint16_t predict_table[5786 * 2];
39
40 static const uint8_t size_table[] = {
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 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
44 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
45 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
46 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7
47 };
48
49 static const int8_t index_table1[] = {
50 -1, 4, -1, 4
51 };
52
53 static const int8_t index_table2[] = {
54 -1, -1, 2, 6, -1, -1, 2, 6
55 };
56
57 static const int8_t index_table3[] = {
58 -1, -1, -1, -1, 1, 2, 4, 6, -1, -1, -1, -1, 1, 2, 4, 6
59 };
60
61 static const int8_t index_table4[] = {
62 -1, -1, -1, -1, -1, -1, -1, -1, 1, 1, 1, 2, 2, 4, 5, 6,
63 -1, -1, -1, -1, -1, -1, -1, -1, 1, 1, 1, 2, 2, 4, 5, 6
64 };
65
66 static const int8_t index_table5[] = {
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 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
70 1, 1, 1, 1, 1, 2, 2, 2, 2, 4, 4, 4, 5, 5, 6, 6
71 };
72
73 static const int8_t index_table6[] = {
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, -1, -1, -1, -1, -1, -1,
76 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2,
77 2, 2, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6,
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, -1, -1, -1, -1, -1, -1,
80 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2,
81 2, 2, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6
82 };
83
84 static const int8_t *const step_index_tables[] = {
85 index_table1, index_table2, index_table3,
86 index_table4, index_table5, index_table6
87 };
88
89 2 static av_cold void predict_table_init(void)
90 {
91
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 130 for (int start_pos = 0; start_pos < 64; start_pos++) {
92 unsigned int dest_pos, table_pos;
93
94 128 for (table_pos = 0, dest_pos = start_pos;
95
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 11520 table_pos < FF_ARRAY_ELEMS(ff_adpcm_step_table);
96 11392 table_pos++, dest_pos += 64) {
97 11392 int put = 0, count, table_value;
98
99 11392 table_value = ff_adpcm_step_table[table_pos];
100
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 79744 for (count = 32; count != 0; count >>= 1) {
101
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 68352 if (start_pos & count)
102 34176 put += table_value;
103 68352 table_value >>= 1;
104 }
105 11392 predict_table[dest_pos] = put;
106 }
107 }
108 2 }
109
110 3 static av_cold int decode_init(AVCodecContext *avctx)
111 {
112 static AVOnce init_static_once = AV_ONCE_INIT;
113
114 3 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
115
116 3 ff_thread_once(&init_static_once, predict_table_init);
117
118 3 return 0;
119 }
120
121 18 static int decode_frame(AVCodecContext *avctx, AVFrame *frame,
122 int *got_frame_ptr, AVPacket *pkt)
123 {
124 GetBitContext gb;
125 int16_t pcm_data[2];
126 uint32_t samples;
127 int8_t channel_hint[2];
128 int ret, chan;
129 18 int channels = 1;
130
131
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 18 if (pkt->size < 13)
132 ✗ return AVERROR_INVALIDDATA;
133
134
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 18 if ((ret = init_get_bits8(&gb, pkt->data, pkt->size)) < 0)
135 ✗ return ret;
136
137 18 samples = get_bits_long(&gb, 32);
138
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 18 if (samples == 0xffffffff) {
139 18 skip_bits_long(&gb, 32);
140 18 samples = get_bits_long(&gb, 32);
141 }
142
143
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 18 if (samples > pkt->size * 2)
144 ✗ return AVERROR_INVALIDDATA;
145
146 18 channel_hint[0] = get_sbits(&gb, 8);
147
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 18 if (channel_hint[0] & 0x80) {
148 18 channel_hint[0] = ~channel_hint[0];
149 18 channels = 2;
150 }
151 18 av_channel_layout_uninit(&avctx->ch_layout);
152 18 av_channel_layout_default(&avctx->ch_layout, channels);
153 18 pcm_data[0] = get_sbits(&gb, 16);
154
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 18 if (channels > 1) {
155 18 channel_hint[1] = get_sbits(&gb, 8);
156 18 pcm_data[1] = get_sbits(&gb, 16);
157 }
158
159 18 frame->nb_samples = samples;
160
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 18 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
161 ✗ return ret;
162
163
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 18 if (show_bits_long(&gb, 32) == MKBETAG('I','M','A','4')) {
164 ✗ int16_t *dest = (int16_t *)frame->data[0];
165 ADPCMChannelStatus cs;
166
167 ✗ skip_bits_long(&gb, 32); /* skip the 'IMA4' tag */
168 ✗ cs.predictor = (int16_t)get_xbits_le(&gb, 16);
169 ✗ cs.step_index = av_clip(get_bits(&gb, 8), 0, 88);
170 ✗ for (int i = 0; i < samples; i++) {
171 ✗ ff_adpcm_ima_qt_expand_nibble(&cs, get_bits(&gb, 4));
172 ✗ for (int j = 0; j < channels; j++)
173 ✗ *dest++ = cs.predictor;
174 }
175 } else {
176
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 54 for (chan = 0; chan < channels; chan++) {
177 36 uint16_t *dest = (uint16_t *)frame->data[0] + chan;
178 36 int step_index = channel_hint[chan];
179 36 int output = pcm_data[chan];
180 int sample;
181
182
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 485136 for (sample = 0; sample < samples; sample++) {
183 int lookup_size, lookup, highbit, lowbits;
184
185 485100 step_index = av_clip(step_index, 0, 88);
186 485100 lookup_size = size_table[step_index];
187 485100 lookup = get_bits(&gb, lookup_size);
188 485100 highbit = 1 << (lookup_size - 1);
189 485100 lowbits = highbit - 1;
190
191
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 485100 if (lookup & highbit)
192 235690 lookup ^= highbit;
193 else
194 249410 highbit = 0;
195
196
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 485100 if (lookup == lowbits) {
197 20815 output = get_sbits(&gb, 16);
198 } else {
199 int predict_index, diff;
200
201 464285 predict_index = (lookup << (7 - lookup_size)) | (step_index << 6);
202 464285 predict_index = av_clip(predict_index, 0, 5785);
203 464285 diff = predict_table[predict_index];
204
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 464285 if (lookup)
205 391538 diff += ff_adpcm_step_table[step_index] >> (lookup_size - 1);
206
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 464285 if (highbit)
207 225304 diff = -diff;
208
209 464285 output = av_clip_int16(output + diff);
210 }
211
212 485100 *dest = output;
213 485100 dest += channels;
214
215 485100 step_index += step_index_tables[lookup_size - 2][lookup];
216 }
217 }
218 }
219
220 18 *got_frame_ptr = 1;
221
222 18 return pkt->size;
223 }
224
225 const FFCodec ff_adpcm_vima_decoder = {
226 .p.name = "adpcm_vima",
227 CODEC_LONG_NAME("LucasArts VIMA audio"),
228 .p.type = AVMEDIA_TYPE_AUDIO,
229 .p.id = AV_CODEC_ID_ADPCM_VIMA,
230 .init = decode_init,
231 FF_CODEC_DECODE_CB(decode_frame),
232 .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF,
233 };
234