1 /*
2 * Simon & Schuster Interactive VAG (de)muxer
3 *
4 * Copyright (C) 2020 Zane van Iperen (zane@zanevaniperen.com)
5 *
6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23 #include "config_components.h"
24
25 #include "libavutil/channel_layout.h"
26 #include "avformat.h"
27 #include "avio_internal.h"
28 #include "internal.h"
29 #include "rawenc.h"
30 #include "libavutil/intreadwrite.h"
31
32 #define KVAG_TAG MKTAG('K', 'V', 'A', 'G')
33 #define KVAG_HEADER_SIZE 14
34 #define KVAG_MAX_READ_SIZE 4096
35
36 typedef struct KVAGHeader {
37 uint32_t magic;
38 uint32_t data_size;
39 uint32_t sample_rate;
40 uint16_t stereo;
41 } KVAGHeader;
42
43 #if CONFIG_KVAG_DEMUXER
kvag_probe(const AVProbeData * p)44 static int kvag_probe(const AVProbeData *p)
45 {
46 if (AV_RL32(p->buf) != KVAG_TAG)
47 return 0;
48
49 return AVPROBE_SCORE_EXTENSION + 1;
50 }
51
kvag_read_header(AVFormatContext * s)52 static int kvag_read_header(AVFormatContext *s)
53 {
54 int ret;
55 AVStream *st;
56 KVAGHeader hdr;
57 AVCodecParameters *par;
58 uint8_t buf[KVAG_HEADER_SIZE];
59
60 if (!(st = avformat_new_stream(s, NULL)))
61 return AVERROR(ENOMEM);
62
63 if ((ret = ffio_read_size(s->pb, buf, KVAG_HEADER_SIZE)) < 0)
64 return ret;
65
66 hdr.magic = AV_RL32(buf + 0);
67 hdr.data_size = AV_RL32(buf + 4);
68 hdr.sample_rate = AV_RL32(buf + 8);
69 hdr.stereo = AV_RL16(buf + 12);
70
71 par = st->codecpar;
72 par->codec_type = AVMEDIA_TYPE_AUDIO;
73 par->codec_id = AV_CODEC_ID_ADPCM_IMA_SSI;
74 par->format = AV_SAMPLE_FMT_S16;
75
76 av_channel_layout_default(&par->ch_layout, !!hdr.stereo + 1);
77 par->sample_rate = hdr.sample_rate;
78 par->bits_per_coded_sample = 4;
79 par->block_align = 1;
80 par->bit_rate = par->ch_layout.nb_channels *
81 (uint64_t)par->sample_rate *
82 par->bits_per_coded_sample;
83
84 avpriv_set_pts_info(st, 64, 1, par->sample_rate);
85 st->start_time = 0;
86 st->duration = hdr.data_size *
87 (8 / par->bits_per_coded_sample) /
88 par->ch_layout.nb_channels;
89
90 return 0;
91 }
92
kvag_read_packet(AVFormatContext * s,AVPacket * pkt)93 static int kvag_read_packet(AVFormatContext *s, AVPacket *pkt)
94 {
95 int ret;
96 AVCodecParameters *par = s->streams[0]->codecpar;
97
98 if ((ret = av_get_packet(s->pb, pkt, KVAG_MAX_READ_SIZE)) < 0)
99 return ret;
100
101 pkt->flags &= ~AV_PKT_FLAG_CORRUPT;
102 pkt->stream_index = 0;
103 pkt->duration = ret * (8 / par->bits_per_coded_sample) / par->ch_layout.nb_channels;
104
105 return 0;
106 }
107
kvag_seek(AVFormatContext * s,int stream_index,int64_t pts,int flags)108 static int kvag_seek(AVFormatContext *s, int stream_index,
109 int64_t pts, int flags)
110 {
111 if (pts != 0)
112 return AVERROR(EINVAL);
113
114 return avio_seek(s->pb, KVAG_HEADER_SIZE, SEEK_SET);
115 }
116
117 const AVInputFormat ff_kvag_demuxer = {
118 .name = "kvag",
119 .long_name = NULL_IF_CONFIG_SMALL("Simon & Schuster Interactive VAG"),
120 .read_probe = kvag_probe,
121 .read_header = kvag_read_header,
122 .read_packet = kvag_read_packet,
123 .read_seek = kvag_seek,
124 };
125 #endif
126
127 #if CONFIG_KVAG_MUXER
kvag_write_init(AVFormatContext * s)128 static int kvag_write_init(AVFormatContext *s)
129 {
130 AVCodecParameters *par;
131
132 if (s->nb_streams != 1) {
133 av_log(s, AV_LOG_ERROR, "KVAG files have exactly one stream\n");
134 return AVERROR(EINVAL);
135 }
136
137 par = s->streams[0]->codecpar;
138
139 if (par->codec_id != AV_CODEC_ID_ADPCM_IMA_SSI) {
140 av_log(s, AV_LOG_ERROR, "%s codec not supported\n",
141 avcodec_get_name(par->codec_id));
142 return AVERROR(EINVAL);
143 }
144
145 if (par->ch_layout.nb_channels > 2) {
146 av_log(s, AV_LOG_ERROR, "KVAG files only support up to 2 channels\n");
147 return AVERROR(EINVAL);
148 }
149
150 if (!(s->pb->seekable & AVIO_SEEKABLE_NORMAL)) {
151 av_log(s, AV_LOG_WARNING, "Stream not seekable, unable to write output file\n");
152 return AVERROR(EINVAL);
153 }
154
155 return 0;
156 }
157
kvag_write_header(AVFormatContext * s)158 static int kvag_write_header(AVFormatContext *s)
159 {
160 uint8_t buf[KVAG_HEADER_SIZE];
161 AVCodecParameters *par = s->streams[0]->codecpar;
162
163 AV_WL32(buf + 0, KVAG_TAG);
164 AV_WL32(buf + 4, 0); /* Data size, we fix this up later. */
165 AV_WL32(buf + 8, par->sample_rate);
166 AV_WL16(buf + 12, par->ch_layout.nb_channels == 2);
167
168 avio_write(s->pb, buf, sizeof(buf));
169 return 0;
170 }
171
kvag_write_trailer(AVFormatContext * s)172 static int kvag_write_trailer(AVFormatContext *s)
173 {
174 int64_t file_size, data_size;
175
176 file_size = avio_tell(s->pb);
177 data_size = file_size - KVAG_HEADER_SIZE;
178 if (data_size < UINT32_MAX) {
179 avio_seek(s->pb, 4, SEEK_SET);
180 avio_wl32(s->pb, (uint32_t)data_size);
181 avio_seek(s->pb, file_size, SEEK_SET);
182 } else {
183 av_log(s, AV_LOG_WARNING,
184 "Filesize %"PRId64" invalid for KVAG, output file will be broken\n",
185 file_size);
186 }
187
188 return 0;
189 }
190
191 const AVOutputFormat ff_kvag_muxer = {
192 .name = "kvag",
193 .long_name = NULL_IF_CONFIG_SMALL("Simon & Schuster Interactive VAG"),
194 .extensions = "vag",
195 .audio_codec = AV_CODEC_ID_ADPCM_IMA_SSI,
196 .video_codec = AV_CODEC_ID_NONE,
197 .init = kvag_write_init,
198 .write_header = kvag_write_header,
199 .write_packet = ff_raw_write_packet,
200 .write_trailer = kvag_write_trailer
201 };
202 #endif
203