1 /*
2 * RedSpark demuxer
3 * Copyright (c) 2013 James Almer
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 "libavcodec/bytestream.h"
23 #include "libavutil/intreadwrite.h"
24 #include "avformat.h"
25 #include "avio.h"
26 #include "internal.h"
27
28 #define HEADER_SIZE 4096
29 #define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))
30
31 typedef struct RedSparkContext {
32 int samples_count;
33 } RedSparkContext;
34
redspark_probe(const AVProbeData * p)35 static int redspark_probe(const AVProbeData *p)
36 {
37 uint32_t key, data;
38 uint8_t header[8];
39
40 /* Decrypt first 8 bytes of the header */
41 data = AV_RB32(p->buf);
42 key = data ^ 0x52656453;
43 data ^= key;
44 AV_WB32(header, data);
45 key = rol(key, 11);
46
47 key += rol(key, 3);
48 data = AV_RB32(p->buf + 4) ^ key;
49 AV_WB32(header + 4, data);
50
51 if (AV_RB64(header) == AV_RB64("RedSpark"))
52 return AVPROBE_SCORE_MAX;
53
54 return 0;
55 }
56
redspark_read_header(AVFormatContext * s)57 static int redspark_read_header(AVFormatContext *s)
58 {
59 AVIOContext *pb = s->pb;
60 RedSparkContext *redspark = s->priv_data;
61 AVCodecParameters *par;
62 GetByteContext gbc;
63 int i, coef_off, ret = 0;
64 uint32_t key, data;
65 uint8_t header[HEADER_SIZE];
66 AVStream *st;
67
68 st = avformat_new_stream(s, NULL);
69 if (!st)
70 return AVERROR(ENOMEM);
71 par = st->codecpar;
72
73 /* Decrypt header */
74 data = avio_rb32(pb);
75 key = data ^ 0x52656453;
76 data ^= key;
77 AV_WB32(header, data);
78 key = rol(key, 11);
79
80 for (i = 4; i < HEADER_SIZE; i += 4) {
81 key += rol(key, 3);
82 data = avio_rb32(pb) ^ key;
83 AV_WB32(header + i, data);
84 }
85
86 par->codec_id = AV_CODEC_ID_ADPCM_THP;
87 par->codec_type = AVMEDIA_TYPE_AUDIO;
88
89 bytestream2_init(&gbc, header, HEADER_SIZE);
90 bytestream2_seek(&gbc, 0x3c, SEEK_SET);
91 par->sample_rate = bytestream2_get_be32u(&gbc);
92 if (par->sample_rate <= 0 || par->sample_rate > 96000) {
93 av_log(s, AV_LOG_ERROR, "Invalid sample rate: %d\n", par->sample_rate);
94 return AVERROR_INVALIDDATA;
95 }
96
97 st->duration = bytestream2_get_be32u(&gbc) * 14;
98 redspark->samples_count = 0;
99 bytestream2_skipu(&gbc, 10);
100 par->channels = bytestream2_get_byteu(&gbc);
101 if (!par->channels) {
102 return AVERROR_INVALIDDATA;
103 }
104
105 coef_off = 0x54 + par->channels * 8;
106 if (bytestream2_get_byteu(&gbc)) // Loop flag
107 coef_off += 16;
108
109 if (coef_off + par->channels * (32 + 14) > HEADER_SIZE) {
110 return AVERROR_INVALIDDATA;
111 }
112
113 if (ff_alloc_extradata(par, 32 * par->channels)) {
114 return AVERROR_INVALIDDATA;
115 }
116
117 /* Get the ADPCM table */
118 bytestream2_seek(&gbc, coef_off, SEEK_SET);
119 for (i = 0; i < par->channels; i++) {
120 if (bytestream2_get_bufferu(&gbc, par->extradata + i * 32, 32) != 32) {
121 return AVERROR_INVALIDDATA;
122 }
123 bytestream2_skipu(&gbc, 14);
124 }
125
126 avpriv_set_pts_info(st, 64, 1, par->sample_rate);
127
128 return ret;
129 }
130
redspark_read_packet(AVFormatContext * s,AVPacket * pkt)131 static int redspark_read_packet(AVFormatContext *s, AVPacket *pkt)
132 {
133 AVCodecParameters *par = s->streams[0]->codecpar;
134 RedSparkContext *redspark = s->priv_data;
135 uint32_t size = 8 * par->channels;
136 int ret;
137
138 if (avio_feof(s->pb) || redspark->samples_count == s->streams[0]->duration)
139 return AVERROR_EOF;
140
141 ret = av_get_packet(s->pb, pkt, size);
142 if (ret != size) {
143 return AVERROR(EIO);
144 }
145
146 pkt->duration = 14;
147 redspark->samples_count += pkt->duration;
148 pkt->stream_index = 0;
149
150 return ret;
151 }
152
153 AVInputFormat ff_redspark_demuxer = {
154 .name = "redspark",
155 .long_name = NULL_IF_CONFIG_SMALL("RedSpark"),
156 .priv_data_size = sizeof(RedSparkContext),
157 .read_probe = redspark_probe,
158 .read_header = redspark_read_header,
159 .read_packet = redspark_read_packet,
160 .extensions = "rsd",
161 };
162