FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavcodec/mlp_parser.c
Date: 2025-11-02 07:30:46
Exec Total Coverage
Lines: 69 86 80.2%
Functions: 2 2 100.0%
Branches: 44 60 73.3%
Line Branch Exec Source
1 /*
2 * MLP parser
3 * Copyright (c) 2007 Ian Caulfield
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 * MLP parser
25 */
26
27 #include <stdint.h>
28
29 #include "libavutil/internal.h"
30 #include "get_bits.h"
31 #include "parser.h"
32 #include "mlp_parse.h"
33 #include "mlp.h"
34 #include "parser_internal.h"
35
36 typedef struct MLPParseContext
37 {
38 ParseContext pc;
39
40 int bytes_left;
41
42 int in_sync;
43
44 int num_substreams;
45 } MLPParseContext;
46
47 9 static av_cold int mlp_init(AVCodecParserContext *s)
48 {
49 9 ff_mlp_init_crc();
50 9 return 0;
51 }
52
53 33479 static int mlp_parse(AVCodecParserContext *s,
54 AVCodecContext *avctx,
55 const uint8_t **poutbuf, int *poutbuf_size,
56 const uint8_t *buf, int buf_size)
57 {
58 33479 MLPParseContext *mp = s->priv_data;
59 int sync_present;
60 uint8_t parity_bits;
61 int next;
62 int ret;
63 33479 int i, p = 0;
64
65 33479 s->key_frame = 0;
66
67 33479 *poutbuf_size = 0;
68 33479 *poutbuf = NULL;
69
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 33479 if (buf_size == 0)
70 9 return 0;
71
72
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 33470 if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
73 ✗ next = buf_size;
74 } else {
75
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 33470 if (!mp->in_sync) {
76 // Not in sync - find a major sync header
77
78
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 7152 for (i = 0; i < buf_size; i++) {
79 7146 mp->pc.state = (mp->pc.state << 8) | buf[i];
80
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 7146 if ((mp->pc.state & 0xfffffffe) == 0xf8726fba &&
81 // ignore if we do not have the data for the start of header
82
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 9 mp->pc.index + i >= 7) {
83 9 mp->in_sync = 1;
84 9 mp->bytes_left = 0;
85 9 break;
86 }
87 }
88
89
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 15 if (!mp->in_sync) {
90
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 6 if (ff_combine_frame(&mp->pc, END_NOT_FOUND, &buf, &buf_size) != -1)
91 ✗ av_log(avctx, AV_LOG_WARNING, "ff_combine_frame failed\n");
92 6 return buf_size;
93 }
94
95
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 9 if ((ret = ff_combine_frame(&mp->pc, i - 7, &buf, &buf_size)) < 0) {
96 ✗ av_log(avctx, AV_LOG_WARNING, "ff_combine_frame failed\n");
97 ✗ return ret;
98 }
99
100 9 return i - 7;
101 }
102
103
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 33455 if (mp->bytes_left == 0) {
104 // Find length of this packet
105
106 /* Copy overread bytes from last frame into buffer. */
107
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 29359 for(; mp->pc.overread>0; mp->pc.overread--) {
108 ✗ mp->pc.buffer[mp->pc.index++]= mp->pc.buffer[mp->pc.overread_index++];
109 }
110
111
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 29359 if (mp->pc.index + buf_size < 2) {
112 ✗ if (ff_combine_frame(&mp->pc, END_NOT_FOUND, &buf, &buf_size) != -1)
113 ✗ av_log(avctx, AV_LOG_WARNING, "ff_combine_frame failed\n");
114 ✗ return buf_size;
115 }
116
117
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 29359 mp->bytes_left = ((mp->pc.index > 0 ? mp->pc.buffer[0] : buf[0]) << 8)
118
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 29359 | (mp->pc.index > 1 ? mp->pc.buffer[1] : buf[1-mp->pc.index]);
119 29359 mp->bytes_left = (mp->bytes_left & 0xfff) * 2;
120
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 29359 if (mp->bytes_left <= 0) { // prevent infinite loop
121 ✗ goto lost_sync;
122 }
123 29359 mp->bytes_left -= mp->pc.index;
124 }
125
126
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 33455 next = (mp->bytes_left > buf_size) ? END_NOT_FOUND : mp->bytes_left;
127
128
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 33455 if (ff_combine_frame(&mp->pc, next, &buf, &buf_size) < 0) {
129 4102 mp->bytes_left -= buf_size;
130 4102 return buf_size;
131 }
132
133 29353 mp->bytes_left = 0;
134 }
135
136
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 29353 sync_present = buf_size >= 8 && (AV_RB32(buf + 4) & 0xfffffffe) == 0xf8726fba;
137
138
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 29353 if (!sync_present) {
139 /* The first nibble of a frame is a parity check of the 4-byte
140 * access unit header and all the 2- or 4-byte substream headers. */
141 // Only check when this isn't a sync frame - syncs have a checksum.
142
143 26471 s->key_frame = 0;
144
145 26471 parity_bits = 0;
146
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 90942 for (i = -1; i < mp->num_substreams; i++) {
147 64471 parity_bits ^= buf[p++];
148 64471 parity_bits ^= buf[p++];
149
150
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 64471 if (i < 0 || buf[p-2] & 0x80) {
151 26639 parity_bits ^= buf[p++];
152 26639 parity_bits ^= buf[p++];
153 }
154 }
155
156
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 26471 if ((((parity_bits >> 4) ^ parity_bits) & 0xF) != 0xF) {
157 ✗ av_log(avctx, AV_LOG_INFO, "mlpparse: Parity check failed.\n");
158 ✗ goto lost_sync;
159 }
160 } else {
161 GetBitContext gb;
162 MLPHeaderInfo mh;
163
164 2882 init_get_bits(&gb, buf + 4, (buf_size - 4) << 3);
165
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 2882 if (ff_mlp_read_major_sync(avctx, &mh, &gb) < 0)
166 ✗ goto lost_sync;
167
168 2882 s->key_frame = 1;
169
170 2882 avctx->bits_per_raw_sample = mh.group1_bits;
171
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 2882 if (avctx->bits_per_raw_sample > 16)
172 652 avctx->sample_fmt = AV_SAMPLE_FMT_S32;
173 else
174 2230 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
175 2882 avctx->sample_rate = mh.group1_samplerate;
176 2882 avctx->frame_size =
177 2882 s->duration = mh.access_unit_size;
178
179 2882 av_channel_layout_uninit(&avctx->ch_layout);
180
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 2882 if (mh.stream_type == 0xbb) {
181 /* MLP stream */
182 2230 av_channel_layout_from_mask(&avctx->ch_layout, mh.channel_layout_mlp);
183 } else { /* mh.stream_type == 0xba */
184 /* TrueHD stream */
185
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 652 if (!mh.channels_thd_stream2) {
186 ✗ av_channel_layout_from_mask(&avctx->ch_layout, mh.channel_layout_thd_stream1);
187 } else {
188 652 av_channel_layout_from_mask(&avctx->ch_layout, mh.channel_layout_thd_stream2);
189 }
190 }
191
192
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 2882 if (!mh.is_vbr) /* Stream is CBR */
193 ✗ avctx->bit_rate = mh.peak_bitrate;
194
195 2882 mp->num_substreams = mh.num_substreams;
196 }
197
198 29353 *poutbuf = buf;
199 29353 *poutbuf_size = buf_size;
200
201 29353 return next;
202
203 ✗ lost_sync:
204 ✗ mp->in_sync = 0;
205 ✗ return 1;
206 }
207
208 const FFCodecParser ff_mlp_parser = {
209 PARSER_CODEC_LIST(AV_CODEC_ID_MLP, AV_CODEC_ID_TRUEHD),
210 .priv_data_size = sizeof(MLPParseContext),
211 .init = mlp_init,
212 .parse = mlp_parse,
213 .close = ff_parse_close,
214 };
215