FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavcodec/adxdec.c
Date: 2025-07-08 13:42:56
Exec Total Coverage
Lines: 77 115 67.0%
Functions: 4 5 80.0%
Branches: 39 76 51.3%
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1 /*
2 * ADX ADPCM codecs
3 * Copyright (c) 2001,2003 BERO
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 #include "libavutil/intreadwrite.h"
23 #include "avcodec.h"
24 #include "adx.h"
25 #include "codec_internal.h"
26 #include "decode.h"
27 #include "get_bits.h"
28
29 /**
30 * @file
31 * SEGA CRI adx codecs.
32 *
33 * Reference documents:
34 * http://ku-www.ss.titech.ac.jp/~yatsushi/adx.html
35 * adx2wav & wav2adx http://www.geocities.co.jp/Playtown/2004/
36 */
37
38 /**
39 * Decode ADX stream header.
40 * Sets avctx->channels and avctx->sample_rate.
41 *
42 * @param avctx codec context
43 * @param buf header data
44 * @param bufsize data size, should be at least 24 bytes
45 * @param[out] header_size size of ADX header
46 * @param[out] coeff 2 LPC coefficients, can be NULL
47 * @return data offset or negative error code if header is invalid
48 */
49 4 static int adx_decode_header(AVCodecContext *avctx, const uint8_t *buf,
50 int bufsize, int *header_size, int *coeff)
51 {
52 int offset, cutoff, channels;
53
54
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 4 if (bufsize < 24)
55 ✗ return AVERROR_INVALIDDATA;
56
57
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 4 if (AV_RB16(buf) != 0x8000)
58 ✗ return AVERROR_INVALIDDATA;
59 4 offset = AV_RB16(buf + 2) + 4;
60
61 /* if copyright string is within the provided data, validate it */
62
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 4 if (bufsize >= offset && offset >= 6 && memcmp(buf + offset - 6, "(c)CRI", 6))
63 ✗ return AVERROR_INVALIDDATA;
64
65 /* check for encoding=3 block_size=18, sample_size=4 */
66
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 4 if (buf[4] != 3 || buf[5] != 18 || buf[6] != 4) {
67 ✗ avpriv_request_sample(avctx, "Support for this ADX format");
68 ✗ return AVERROR_PATCHWELCOME;
69 }
70
71 /* channels */
72 4 channels = buf[7];
73
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 4 if (channels <= 0 || channels > MAX_CHANNELS)
74 ✗ return AVERROR_INVALIDDATA;
75
76
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 4 if (avctx->ch_layout.nb_channels != channels) {
77 ✗ av_channel_layout_uninit(&avctx->ch_layout);
78 ✗ avctx->ch_layout.order = AV_CHANNEL_ORDER_UNSPEC;
79 ✗ avctx->ch_layout.nb_channels = channels;
80 }
81
82 /* sample rate */
83 4 avctx->sample_rate = AV_RB32(buf + 8);
84
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 4 if (avctx->sample_rate < 1 ||
85
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 4 avctx->sample_rate > INT_MAX / (channels * BLOCK_SIZE * 8))
86 ✗ return AVERROR_INVALIDDATA;
87
88 /* bit rate */
89 4 avctx->bit_rate = avctx->sample_rate * channels * BLOCK_SIZE * 8 / BLOCK_SAMPLES;
90
91 /* LPC coefficients */
92
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 4 if (coeff) {
93 4 cutoff = AV_RB16(buf + 16);
94 4 ff_adx_calculate_coeffs(cutoff, avctx->sample_rate, COEFF_BITS, coeff);
95 }
96
97 4 *header_size = offset;
98 4 return 0;
99 }
100
101 4 static av_cold int adx_decode_init(AVCodecContext *avctx)
102 {
103 4 ADXContext *c = avctx->priv_data;
104 int ret, header_size;
105
106
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 4 if (avctx->extradata_size >= 24) {
107
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 2 if ((ret = adx_decode_header(avctx, avctx->extradata,
108 avctx->extradata_size, &header_size,
109 2 c->coeff)) < 0) {
110 ✗ av_log(avctx, AV_LOG_ERROR, "error parsing ADX header\n");
111 ✗ return AVERROR_INVALIDDATA;
112 }
113 2 c->channels = avctx->ch_layout.nb_channels;
114 2 c->header_parsed = 1;
115 }
116
117 4 avctx->sample_fmt = AV_SAMPLE_FMT_S16P;
118
119 4 return 0;
120 }
121
122 /**
123 * Decode 32 samples from 18 bytes.
124 *
125 * A 16-bit scalar value is applied to 32 residuals, which then have a
126 * 2nd-order LPC filter applied to it to form the output signal for a single
127 * channel.
128 */
129 16798 static int adx_decode(ADXContext *c, int16_t *out, int offset,
130 const uint8_t *in, int ch)
131 {
132 16798 ADXChannelState *prev = &c->prev[ch];
133 GetBitContext gb;
134 16798 int scale = AV_RB16(in);
135 int i;
136 int s0, s1, s2, d;
137
138 /* check if this is an EOF packet */
139
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 16798 if (scale & 0x8000)
140 ✗ return -1;
141
142 16798 init_get_bits(&gb, in + 2, (BLOCK_SIZE - 2) * 8);
143 16798 out += offset;
144 16798 s1 = prev->s1;
145 16798 s2 = prev->s2;
146
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 554334 for (i = 0; i < BLOCK_SAMPLES; i++) {
147 537536 d = get_sbits(&gb, 4);
148 537536 s0 = d * scale + ((c->coeff[0] * s1 + c->coeff[1] * s2) >> COEFF_BITS);
149 537536 s2 = s1;
150 537536 s1 = av_clip_int16(s0);
151 537536 *out++ = s1;
152 }
153 16798 prev->s1 = s1;
154 16798 prev->s2 = s2;
155
156 16798 return 0;
157 }
158
159 68 static int adx_decode_frame(AVCodecContext *avctx, AVFrame *frame,
160 int *got_frame_ptr, AVPacket *avpkt)
161 {
162 68 int buf_size = avpkt->size;
163 68 ADXContext *c = avctx->priv_data;
164 int16_t **samples;
165 int samples_offset;
166 68 const uint8_t *buf = avpkt->data;
167 68 const uint8_t *buf_end = buf + avpkt->size;
168 int num_blocks, ch, ret;
169 size_t new_extradata_size;
170 uint8_t *new_extradata;
171
172 68 new_extradata = av_packet_get_side_data(avpkt, AV_PKT_DATA_NEW_EXTRADATA,
173 &new_extradata_size);
174
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 68 if (new_extradata && new_extradata_size > 0) {
175 int header_size;
176 ✗ if ((ret = adx_decode_header(avctx, new_extradata,
177 new_extradata_size, &header_size,
178 ✗ c->coeff)) < 0) {
179 ✗ av_log(avctx, AV_LOG_ERROR, "error parsing new ADX extradata\n");
180 ✗ return AVERROR_INVALIDDATA;
181 }
182
183 ✗ c->eof = 0;
184 }
185
186
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 68 if (c->eof) {
187 ✗ *got_frame_ptr = 0;
188 ✗ return buf_size;
189 }
190
191
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 68 if (!c->header_parsed && buf_size >= 2 && AV_RB16(buf) == 0x8000) {
192 int header_size;
193
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 2 if ((ret = adx_decode_header(avctx, buf, buf_size, &header_size,
194 2 c->coeff)) < 0) {
195 ✗ av_log(avctx, AV_LOG_ERROR, "error parsing ADX header\n");
196 ✗ return AVERROR_INVALIDDATA;
197 }
198 2 c->channels = avctx->ch_layout.nb_channels;
199 2 c->header_parsed = 1;
200
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 2 if (buf_size < header_size)
201 ✗ return AVERROR_INVALIDDATA;
202 2 buf += header_size;
203 2 buf_size -= header_size;
204 }
205
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 68 if (!c->header_parsed)
206 ✗ return AVERROR_INVALIDDATA;
207
208 /* calculate number of blocks in the packet */
209 68 num_blocks = buf_size / (BLOCK_SIZE * c->channels);
210
211 /* if the packet is not an even multiple of BLOCK_SIZE, check for an EOF
212 packet */
213
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 68 if (!num_blocks || buf_size % (BLOCK_SIZE * c->channels)) {
214 ✗ if (buf_size >= 4 && (AV_RB16(buf) & 0x8000)) {
215 ✗ c->eof = 1;
216 ✗ *got_frame_ptr = 0;
217 ✗ return avpkt->size;
218 }
219 ✗ return AVERROR_INVALIDDATA;
220 }
221
222 /* get output buffer */
223 68 frame->nb_samples = num_blocks * BLOCK_SAMPLES;
224
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 68 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
225 ✗ return ret;
226 68 samples = (int16_t **)frame->extended_data;
227 68 samples_offset = 0;
228
229
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 8467 while (num_blocks--) {
230
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 25197 for (ch = 0; ch < c->channels; ch++) {
231
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 16798 if (buf_end - buf < BLOCK_SIZE || adx_decode(c, samples[ch], samples_offset, buf, ch)) {
232 ✗ c->eof = 1;
233 ✗ buf = avpkt->data + avpkt->size;
234 ✗ break;
235 }
236 16798 buf_size -= BLOCK_SIZE;
237 16798 buf += BLOCK_SIZE;
238 }
239
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 8399 if (!c->eof)
240 8399 samples_offset += BLOCK_SAMPLES;
241 }
242
243 68 frame->nb_samples = samples_offset;
244 68 *got_frame_ptr = 1;
245
246 68 return buf - avpkt->data;
247 }
248
249 ✗ static void adx_decode_flush(AVCodecContext *avctx)
250 {
251 ✗ ADXContext *c = avctx->priv_data;
252 ✗ memset(c->prev, 0, sizeof(c->prev));
253 ✗ c->eof = 0;
254 ✗ }
255
256 const FFCodec ff_adpcm_adx_decoder = {
257 .p.name = "adpcm_adx",
258 CODEC_LONG_NAME("SEGA CRI ADX ADPCM"),
259 .p.type = AVMEDIA_TYPE_AUDIO,
260 .p.id = AV_CODEC_ID_ADPCM_ADX,
261 .priv_data_size = sizeof(ADXContext),
262 .init = adx_decode_init,
263 FF_CODEC_DECODE_CB(adx_decode_frame),
264 .flush = adx_decode_flush,
265 .p.capabilities = AV_CODEC_CAP_CHANNEL_CONF |
266 AV_CODEC_CAP_DR1,
267 CODEC_SAMPLEFMTS(AV_SAMPLE_FMT_S16P),
268 };
269