FFmpeg  4.3
kvag.c
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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 #include "avformat.h"
23 #include "internal.h"
24 #include "rawenc.h"
25 #include "libavutil/intreadwrite.h"
26 
27 #define KVAG_TAG MKTAG('K', 'V', 'A', 'G')
28 #define KVAG_HEADER_SIZE 14
29 #define KVAG_MAX_READ_SIZE 4096
30 
31 typedef struct KVAGHeader {
32  uint32_t magic;
33  uint32_t data_size;
34  uint32_t sample_rate;
35  uint16_t stereo;
36 } KVAGHeader;
37 
38 #if CONFIG_KVAG_DEMUXER
39 static int kvag_probe(const AVProbeData *p)
40 {
41  if (AV_RL32(p->buf) != KVAG_TAG)
42  return 0;
43 
44  return AVPROBE_SCORE_EXTENSION + 1;
45 }
46 
47 static int kvag_read_header(AVFormatContext *s)
48 {
49  int ret;
50  AVStream *st;
51  KVAGHeader hdr;
52  AVCodecParameters *par;
54 
55  if (!(st = avformat_new_stream(s, NULL)))
56  return AVERROR(ENOMEM);
57 
58  if ((ret = avio_read(s->pb, buf, KVAG_HEADER_SIZE)) < 0)
59  return ret;
60  else if (ret != KVAG_HEADER_SIZE)
61  return AVERROR(EIO);
62 
63  hdr.magic = AV_RL32(buf + 0);
64  hdr.data_size = AV_RL32(buf + 4);
65  hdr.sample_rate = AV_RL32(buf + 8);
66  hdr.stereo = AV_RL16(buf + 12);
67 
68  par = st->codecpar;
72 
73  if (hdr.stereo) {
75  par->channels = 2;
76  } else {
78  par->channels = 1;
79  }
80 
81  par->sample_rate = hdr.sample_rate;
82  par->bits_per_coded_sample = 4;
83  par->bits_per_raw_sample = 16;
84  par->block_align = 1;
85  par->bit_rate = par->channels *
86  par->sample_rate *
88 
89  avpriv_set_pts_info(st, 64, 1, par->sample_rate);
90  st->start_time = 0;
91  st->duration = hdr.data_size *
92  (8 / par->bits_per_coded_sample) /
93  par->channels;
94 
95  return 0;
96 }
97 
98 static int kvag_read_packet(AVFormatContext *s, AVPacket *pkt)
99 {
100  int ret;
101  AVCodecParameters *par = s->streams[0]->codecpar;
102 
103  if ((ret = av_get_packet(s->pb, pkt, KVAG_MAX_READ_SIZE)) < 0)
104  return ret;
105 
106  pkt->flags &= ~AV_PKT_FLAG_CORRUPT;
107  pkt->stream_index = 0;
108  pkt->duration = ret * (8 / par->bits_per_coded_sample) / par->channels;
109 
110  return 0;
111 }
112 
114  .name = "kvag",
115  .long_name = NULL_IF_CONFIG_SMALL("Simon & Schuster Interactive VAG"),
116  .read_probe = kvag_probe,
117  .read_header = kvag_read_header,
118  .read_packet = kvag_read_packet
119 };
120 #endif
121 
122 #if CONFIG_KVAG_MUXER
123 static int kvag_write_init(AVFormatContext *s)
124 {
125  AVCodecParameters *par;
126 
127  if (s->nb_streams != 1) {
128  av_log(s, AV_LOG_ERROR, "KVAG files have exactly one stream\n");
129  return AVERROR(EINVAL);
130  }
131 
132  par = s->streams[0]->codecpar;
133 
134  if (par->codec_id != AV_CODEC_ID_ADPCM_IMA_SSI) {
135  av_log(s, AV_LOG_ERROR, "%s codec not supported\n",
136  avcodec_get_name(par->codec_id));
137  return AVERROR(EINVAL);
138  }
139 
140  if (par->channels > 2) {
141  av_log(s, AV_LOG_ERROR, "KVAG files only support up to 2 channels\n");
142  return AVERROR(EINVAL);
143  }
144 
145  if (!(s->pb->seekable & AVIO_SEEKABLE_NORMAL)) {
146  av_log(s, AV_LOG_WARNING, "Stream not seekable, unable to write output file\n");
147  return AVERROR(EINVAL);
148  }
149 
150  return 0;
151 }
152 
153 static int kvag_write_header(AVFormatContext *s)
154 {
156  AVCodecParameters *par = s->streams[0]->codecpar;
157 
158  AV_WL32(buf + 0, KVAG_TAG);
159  AV_WL32(buf + 4, 0); /* Data size, we fix this up later. */
160  AV_WL32(buf + 8, par->sample_rate);
161  AV_WL16(buf + 12, par->channels == 2);
162 
163  avio_write(s->pb, buf, sizeof(buf));
164  return 0;
165 }
166 
167 static int kvag_write_trailer(AVFormatContext *s)
168 {
169  int64_t file_size, data_size;
170 
171  file_size = avio_tell(s->pb);
172  data_size = file_size - KVAG_HEADER_SIZE;
173  if (data_size < UINT32_MAX) {
174  avio_seek(s->pb, 4, SEEK_SET);
175  avio_wl32(s->pb, (uint32_t)data_size);
176  avio_seek(s->pb, file_size, SEEK_SET);
177  } else {
179  "Filesize %"PRId64" invalid for KVAG, output file will be broken\n",
180  file_size);
181  }
182 
183  return 0;
184 }
185 
187  .name = "kvag",
188  .long_name = NULL_IF_CONFIG_SMALL("Simon & Schuster Interactive VAG"),
189  .extensions = "vag",
190  .audio_codec = AV_CODEC_ID_ADPCM_IMA_SSI,
191  .video_codec = AV_CODEC_ID_NONE,
192  .init = kvag_write_init,
193  .write_header = kvag_write_header,
194  .write_packet = ff_raw_write_packet,
195  .write_trailer = kvag_write_trailer
196 };
197 #endif
#define NULL
Definition: coverity.c:32
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: utils.c:4938
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:241
#define AV_RL16
Definition: intreadwrite.h:42
static AVPacket pkt
#define AV_CH_LAYOUT_STEREO
This struct describes the properties of an encoded stream.
Definition: codec_par.h:52
AVOutputFormat ff_kvag_muxer
Format I/O context.
Definition: avformat.h:1351
#define KVAG_MAX_READ_SIZE
Definition: kvag.c:29
void avio_wl32(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:367
uint8_t
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: packet.h:373
AVInputFormat ff_kvag_demuxer
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4519
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1419
int av_get_packet(AVIOContext *s, AVPacket *pkt, int size)
Allocate and read the payload of a packet and initialize its fields with default values.
Definition: utils.c:304
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
void avio_write(AVIOContext *s, const unsigned char *buf, int size)
Definition: aviobuf.c:213
uint64_t channel_layout
Audio only.
Definition: codec_par.h:162
#define av_log(a,...)
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:625
int64_t bit_rate
The average bitrate of the encoded data (in bits per second).
Definition: codec_par.h:89
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
int flags
A combination of AV_PKT_FLAG values.
Definition: packet.h:361
uint32_t magic
Definition: kvag.c:32
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:443
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:1407
int block_align
Audio only.
Definition: codec_par.h:177
int seekable
A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
Definition: avio.h:260
const char * name
Definition: avformat.h:500
#define s(width, name)
Definition: cbs_vp9.c:257
uint32_t sample_rate
Definition: kvag.c:34
#define KVAG_TAG
Definition: kvag.c:27
int ff_raw_write_packet(AVFormatContext *s, AVPacket *pkt)
Definition: rawenc.c:29
#define AV_RL32
Definition: intreadwrite.h:146
Stream structure.
Definition: avformat.h:876
#define AVIO_SEEKABLE_NORMAL
Seeking works like for a local file.
Definition: avio.h:40
AVIOContext * pb
I/O context.
Definition: avformat.h:1393
#define KVAG_HEADER_SIZE
Definition: kvag.c:28
#define AVPROBE_SCORE_EXTENSION
score for file extension
Definition: avformat.h:451
This structure contains the data a format has to probe a file.
Definition: avformat.h:441
int bits_per_raw_sample
This is the number of valid bits in each output sample.
Definition: codec_par.h:115
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:925
int sample_rate
Audio only.
Definition: codec_par.h:170
Main libavformat public API header.
uint16_t stereo
Definition: kvag.c:35
int64_t start_time
Decoding: pts of the first frame of the stream in presentation order, in stream time base...
Definition: avformat.h:915
signed 16 bits
Definition: samplefmt.h:61
uint32_t data_size
Definition: kvag.c:33
#define AV_WL16(p, v)
Definition: intreadwrite.h:412
const char * avcodec_get_name(enum AVCodecID id)
Get the name of a codec.
Definition: utils.c:1184
#define AV_PKT_FLAG_CORRUPT
The packet content is corrupted.
Definition: packet.h:389
int bits_per_coded_sample
The number of bits per sample in the codedwords.
Definition: codec_par.h:102
int channels
Audio only.
Definition: codec_par.h:166
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:650
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1023
int stream_index
Definition: packet.h:357
#define AV_CH_LAYOUT_MONO
This structure stores compressed data.
Definition: packet.h:332
#define AV_WL32(p, v)
Definition: intreadwrite.h:426