FFmpeg  4.4.6
mca.c
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1 /*
2  * MCA demuxer
3  * Copyright (c) 2020 Zixing Liu
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 "avio_internal.h"
25 #include "internal.h"
26 
27 typedef struct MCADemuxContext {
28  uint32_t block_count;
29  uint16_t block_size;
30  uint32_t current_block;
31  uint32_t data_start;
34 
35 static int probe(const AVProbeData *p)
36 {
37  if (AV_RL32(p->buf) == MKTAG('M', 'A', 'D', 'P') &&
38  AV_RL16(p->buf + 4) <= 0x5)
39  return AVPROBE_SCORE_MAX / 3 * 2;
40  return 0;
41 }
42 
44 {
45  AVStream *st;
46  MCADemuxContext *m = s->priv_data;
47  AVCodecParameters *par;
48  int64_t file_size = avio_size(s->pb);
49  uint16_t version = 0;
50  uint32_t header_size, data_size, data_offset, loop_start, loop_end,
51  nb_samples, nb_metadata, coef_offset = 0;
52  int ch, ret;
53  int64_t ret_size;
54 
55  st = avformat_new_stream(s, NULL);
56  if (!st)
57  return AVERROR(ENOMEM);
58  par = st->codecpar;
60 
61  // parse file headers
62  avio_skip(s->pb, 0x4); // skip the file magic
63  version = avio_rl16(s->pb);
64  avio_skip(s->pb, 0x2); // padding
65  par->channels = avio_r8(s->pb);
66  avio_skip(s->pb, 0x1); // padding
67  m->block_size = avio_rl16(s->pb);
68  nb_samples = avio_rl32(s->pb);
69  par->sample_rate = avio_rl32(s->pb);
70  loop_start = avio_rl32(s->pb);
71  loop_end = avio_rl32(s->pb);
72  header_size = avio_rl32(s->pb);
73  data_size = avio_rl32(s->pb);
74  avio_skip(s->pb, 0x4);
75  nb_metadata = avio_rl16(s->pb);
76  avio_skip(s->pb, 0x2); // unknown u16 field
77 
78  // samples per frame = 14; frame size = 8 (2^3)
79  m->samples_per_block = (m->block_size * 14) >> 3;
80 
81  if (m->samples_per_block < 1)
82  return AVERROR_INVALIDDATA;
83 
84  m->block_count = nb_samples / m->samples_per_block;
85  st->duration = nb_samples;
86 
87  // sanity checks
88  if (!par->channels || par->sample_rate <= 0
89  || loop_start > loop_end || m->block_count < 1)
90  return AVERROR_INVALIDDATA;
91  if ((ret = av_dict_set_int(&s->metadata, "loop_start",
92  av_rescale(loop_start, AV_TIME_BASE,
93  par->sample_rate), 0)) < 0)
94  return ret;
95  if ((ret = av_dict_set_int(&s->metadata, "loop_end",
96  av_rescale(loop_end, AV_TIME_BASE,
97  par->sample_rate), 0)) < 0)
98  return ret;
99  if ((32 + 4 + m->block_size) > (INT_MAX / par->channels) ||
100  (32 + 4 + m->block_size) * par->channels > INT_MAX - 8)
101  return AVERROR_INVALIDDATA;
102  avpriv_set_pts_info(st, 64, 1, par->sample_rate);
103 
104  if (version <= 4) {
105  // version <= 4 needs to use the file size to calculate the offsets
106  if (file_size < 0) {
107  return AVERROR(EIO);
108  }
109  if (file_size - data_size > UINT32_MAX)
110  return AVERROR_INVALIDDATA;
111  m->data_start = file_size - data_size;
112  if (version <= 3) {
113  nb_metadata = 0;
114  // header_size is not available or incorrect in older versions
115  header_size = m->data_start;
116  }
117  } else if (version == 5) {
118  // read data_start location from the header
119  if (0x30 * par->channels + 0x4 > header_size)
120  return AVERROR_INVALIDDATA;
121  data_offset = header_size - 0x30 * par->channels - 0x4;
122  if ((ret_size = avio_seek(s->pb, data_offset, SEEK_SET)) < 0)
123  return ret_size;
124  m->data_start = avio_rl32(s->pb);
125  // check if the metadata is reasonable
126  if (file_size > 0 && (int64_t)m->data_start + data_size > file_size) {
127  // the header is broken beyond repair
128  if ((int64_t)header_size + data_size > file_size) {
130  "MCA metadata corrupted, unable to determine the data offset.\n");
131  return AVERROR_INVALIDDATA;
132  }
133  // recover the data_start information from the data size
135  "Incorrect header size found in metadata, "
136  "header size approximated from the data size\n");
137  if (file_size - data_offset > UINT32_MAX)
138  return AVERROR_INVALIDDATA;
139  m->data_start = file_size - data_size;
140  }
141  } else {
142  avpriv_request_sample(s, "version %d", version);
143  return AVERROR_PATCHWELCOME;
144  }
145 
146  // coefficient alignment = 0x30; metadata size = 0x14
147  if (0x30 * par->channels + nb_metadata * 0x14 > header_size)
148  return AVERROR_INVALIDDATA;
149  coef_offset =
150  header_size - 0x30 * par->channels + nb_metadata * 0x14;
151 
152  st->start_time = 0;
154 
155  ret = ff_alloc_extradata(st->codecpar, 32 * par->channels);
156  if (ret < 0)
157  return ret;
158 
159  if ((ret_size = avio_seek(s->pb, coef_offset, SEEK_SET)) < 0)
160  return ret_size;
161  for (ch = 0; ch < par->channels; ch++) {
162  if ((ret = ffio_read_size(s->pb, par->extradata + ch * 32, 32)) < 0)
163  return ret;
164  // 0x30 (alignment) - 0x20 (actual size, 32) = 0x10 (padding)
165  avio_skip(s->pb, 0x10);
166  }
167 
168  // seek to the beginning of the adpcm data
169  // there are some files where the adpcm audio data is not immediately after the header
170  if ((ret_size = avio_seek(s->pb, m->data_start, SEEK_SET)) < 0)
171  return ret_size;
172 
173  return 0;
174 }
175 
177 {
178  AVCodecParameters *par = s->streams[0]->codecpar;
179  MCADemuxContext *m = s->priv_data;
180  uint16_t size = m->block_size;
181  uint32_t samples = m->samples_per_block;
182  int ret = 0;
183 
184  if (avio_feof(s->pb))
185  return AVERROR_EOF;
186  m->current_block++;
187  if (m->current_block > m->block_count)
188  return AVERROR_EOF;
189 
190  if ((ret = av_get_packet(s->pb, pkt, size * par->channels)) < 0)
191  return ret;
192  pkt->duration = samples;
193  pkt->stream_index = 0;
194 
195  return 0;
196 }
197 
198 static int read_seek(AVFormatContext *s, int stream_index,
199  int64_t timestamp, int flags)
200 {
201  AVStream *st = s->streams[stream_index];
202  MCADemuxContext *m = s->priv_data;
203  int64_t ret = 0;
204 
205  if (timestamp < 0)
206  timestamp = 0;
207  timestamp /= m->samples_per_block;
208  if (timestamp >= m->block_count)
209  timestamp = m->block_count - 1;
210  ret = avio_seek(s->pb, m->data_start + timestamp * m->block_size *
211  st->codecpar->channels, SEEK_SET);
212  if (ret < 0)
213  return ret;
214 
215  m->current_block = timestamp;
216  ff_update_cur_dts(s, st, timestamp * m->samples_per_block);
217  return 0;
218 }
219 
221  .name = "mca",
222  .long_name = NULL_IF_CONFIG_SMALL("MCA Audio Format"),
223  .priv_data_size = sizeof(MCADemuxContext),
224  .read_probe = probe,
227  .read_seek = read_seek,
228  .extensions = "mca",
229 };
Main libavformat public API header.
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:453
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:310
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:253
int64_t avio_size(AVIOContext *s)
Get the filesize.
Definition: aviobuf.c:342
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:364
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:734
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:337
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:750
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:624
int ffio_read_size(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:682
#define AV_RL16
Definition: intreadwrite.h:42
#define AV_RL32
Definition: intreadwrite.h:146
#define flags(name, subs,...)
Definition: cbs_av1.c:572
#define s(width, name)
Definition: cbs_vp9.c:257
#define MKTAG(a, b, c, d)
Definition: common.h:478
#define NULL
Definition: coverity.c:32
long long int64_t
Definition: coverity.c:34
@ AV_CODEC_ID_ADPCM_THP_LE
Definition: codec_id.h:390
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4509
int av_dict_set_int(AVDictionary **pm, const char *key, int64_t value, int flags)
Convenience wrapper for av_dict_set that converts the value to a string and stores it.
Definition: dict.c:147
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:62
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
#define AVERROR_EOF
End of file.
Definition: error.h:55
#define AVERROR(e)
Definition: error.h:43
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:200
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:194
int64_t av_rescale(int64_t a, int64_t b, int64_t c)
Rescale a 64-bit integer with rounding to nearest.
Definition: mathematics.c:129
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
#define AV_TIME_BASE
Internal time base represented as integer.
Definition: avutil.h:254
void ff_update_cur_dts(AVFormatContext *s, AVStream *ref_st, int64_t timestamp)
Update cur_dts of all streams based on the given timestamp and AVStream.
Definition: utils.c:1927
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:4945
int ff_alloc_extradata(AVCodecParameters *par, int size)
Allocate extradata with additional AV_INPUT_BUFFER_PADDING_SIZE at end which is always set to 0.
Definition: utils.c:3314
static int read_probe(const AVProbeData *pd)
Definition: jvdec.c:55
common internal API header
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
version
Definition: libkvazaar.c:326
static int read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
Definition: mca.c:198
AVInputFormat ff_mca_demuxer
Definition: mca.c:220
static int read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: mca.c:176
static int read_header(AVFormatContext *s)
Definition: mca.c:43
static int probe(const AVProbeData *p)
Definition: mca.c:35
This struct describes the properties of an encoded stream.
Definition: codec_par.h:52
int channels
Audio only.
Definition: codec_par.h:166
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
uint8_t * extradata
Extra binary data needed for initializing the decoder, codec-dependent.
Definition: codec_par.h:74
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
int sample_rate
Audio only.
Definition: codec_par.h:170
Format I/O context.
Definition: avformat.h:1232
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:645
This structure stores compressed data.
Definition: packet.h:346
int stream_index
Definition: packet.h:371
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: packet.h:387
This structure contains the data a format has to probe a file.
Definition: avformat.h:441
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:443
Stream structure.
Definition: avformat.h:873
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1038
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:922
int64_t start_time
Decoding: pts of the first frame of the stream in presentation order, in stream time base.
Definition: avformat.h:912
uint32_t data_start
Definition: mca.c:31
uint32_t samples_per_block
Definition: mca.c:32
uint32_t block_count
Definition: mca.c:28
uint32_t current_block
Definition: mca.c:30
uint16_t block_size
Definition: mca.c:29
#define avpriv_request_sample(...)
#define av_log(a,...)
AVPacket * pkt
Definition: movenc.c:59
int size