FFmpeg
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:200
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:253
static AVPacket pkt
#define AV_CH_LAYOUT_STEREO
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_RL16
Definition: bytestream.h:87
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:379
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:225
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:637
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:194
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:153
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
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:1193
#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
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later.That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another.Frame references ownership and permissions
#define AV_CH_LAYOUT_MONO
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:87
This structure stores compressed data.
Definition: packet.h:332
#define AV_WL32(p, v)
Definition: intreadwrite.h:426