FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavformat/sdsdec.c
Date: 2024-04-24 18:52:15
Exec Total Coverage
Lines: 3 70 4.3%
Functions: 1 6 16.7%
Branches: 1 34 2.9%

Line Branch Exec Source
1 /*
2 * MIDI Sample Dump Standard format demuxer
3 * Copyright (c) 2017 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 #include "libavutil/intreadwrite.h"
23 #include "avformat.h"
24 #include "demux.h"
25 #include "internal.h"
26
27 typedef struct SDSContext {
28 uint8_t data[120];
29 int bit_depth;
30 int size;
31 void (*read_block)(const uint8_t *src, uint32_t *dst);
32 } SDSContext;
33
34 7127 static int sds_probe(const AVProbeData *p)
35 {
36
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7127 if (AV_RB32(p->buf) == 0xF07E0001 && p->buf[20] == 0xF7 &&
37 p->buf[6] >= 8 && p->buf[6] <= 28)
38 return AVPROBE_SCORE_EXTENSION;
39 7127 return 0;
40 }
41
42 static void byte2_read(const uint8_t *src, uint32_t *dst)
43 {
44 int i;
45
46 for (i = 0; i < 120; i += 2) {
47 unsigned sample = ((unsigned)src[i + 0] << 25) + ((unsigned)src[i + 1] << 18);
48
49 dst[i / 2] = sample;
50 }
51 }
52
53 static void byte3_read(const uint8_t *src, uint32_t *dst)
54 {
55 int i;
56
57 for (i = 0; i < 120; i += 3) {
58 unsigned sample;
59
60 sample = ((unsigned)src[i + 0] << 25) | ((unsigned)src[i + 1] << 18) | ((unsigned)src[i + 2] << 11);
61 dst[i / 3] = sample;
62 }
63 }
64
65 static void byte4_read(const uint8_t *src, uint32_t *dst)
66 {
67 int i;
68
69 for (i = 0; i < 120; i += 4) {
70 unsigned sample;
71
72 sample = ((unsigned)src[i + 0] << 25) | ((unsigned)src[i + 1] << 18) | ((unsigned)src[i + 2] << 11) | ((unsigned)src[i + 3] << 4);
73 dst[i / 4] = sample;
74 }
75 }
76
77 #define SDS_3BYTE_TO_INT_DECODE(x) (((x) & 0x7F) | (((x) & 0x7F00) >> 1) | (((x) & 0x7F0000) >> 2))
78
79 static int sds_read_header(AVFormatContext *ctx)
80 {
81 SDSContext *s = ctx->priv_data;
82 unsigned sample_period;
83 AVIOContext *pb = ctx->pb;
84 AVStream *st;
85
86 st = avformat_new_stream(ctx, NULL);
87 if (!st)
88 return AVERROR(ENOMEM);
89
90 avio_skip(pb, 4);
91 avio_skip(pb, 2);
92
93 s->bit_depth = avio_r8(pb);
94 if (s->bit_depth < 8 || s->bit_depth > 28)
95 return AVERROR_INVALIDDATA;
96
97 if (s->bit_depth < 14) {
98 s->read_block = byte2_read;
99 s->size = 60 * 4;
100 } else if (s->bit_depth < 21) {
101 s->read_block = byte3_read;
102 s->size = 40 * 4;
103 } else {
104 s->read_block = byte4_read;
105 s->size = 30 * 4;
106 }
107 st->codecpar->codec_id = AV_CODEC_ID_PCM_U32LE;
108
109 sample_period = avio_rl24(pb);
110 sample_period = SDS_3BYTE_TO_INT_DECODE(sample_period);
111 avio_skip(pb, 11);
112
113 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
114 st->codecpar->ch_layout.nb_channels = 1;
115 st->codecpar->sample_rate = sample_period ? 1000000000 / sample_period : 16000;
116 st->duration = av_rescale((avio_size(pb) - 21) / 127, s->size, 4);
117
118 avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
119
120 return 0;
121 }
122
123 static int sds_read_packet(AVFormatContext *ctx, AVPacket *pkt)
124 {
125 SDSContext *s = ctx->priv_data;
126 AVIOContext *pb = ctx->pb;
127 int64_t pos;
128 int ret;
129
130 if (avio_feof(pb))
131 return AVERROR_EOF;
132
133 pos = avio_tell(pb);
134 if (avio_rb16(pb) != 0xF07E)
135 return AVERROR_INVALIDDATA;
136 avio_skip(pb, 3);
137
138 ret = av_new_packet(pkt, s->size);
139 if (ret < 0)
140 return ret;
141
142 ret = avio_read(pb, s->data, 120);
143
144 s->read_block(s->data, (uint32_t *)pkt->data);
145
146 avio_skip(pb, 1); // checksum
147 if (avio_r8(pb) != 0xF7)
148 return AVERROR_INVALIDDATA;
149
150 pkt->flags &= ~AV_PKT_FLAG_CORRUPT;
151 pkt->stream_index = 0;
152 pkt->pos = pos;
153
154 return ret;
155 }
156
157 const FFInputFormat ff_sds_demuxer = {
158 .p.name = "sds",
159 .p.long_name = NULL_IF_CONFIG_SMALL("MIDI Sample Dump Standard"),
160 .p.extensions = "sds",
161 .p.flags = AVFMT_GENERIC_INDEX,
162 .priv_data_size = sizeof(SDSContext),
163 .read_probe = sds_probe,
164 .read_header = sds_read_header,
165 .read_packet = sds_read_packet,
166 };
167