FFmpeg
apetag.c
Go to the documentation of this file.
1 /*
2  * APE tag handling
3  * Copyright (c) 2007 Benjamin Zores <ben@geexbox.org>
4  * based upon libdemac from Dave Chapman.
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 <inttypes.h>
24 
25 #include "libavutil/intreadwrite.h"
26 #include "libavutil/dict.h"
27 #include "avformat.h"
28 #include "avio_internal.h"
29 #include "apetag.h"
30 #include "internal.h"
31 
32 #define APE_TAG_FLAG_CONTAINS_HEADER (1U << 31)
33 #define APE_TAG_FLAG_LACKS_FOOTER (1 << 30)
34 #define APE_TAG_FLAG_IS_HEADER (1 << 29)
35 #define APE_TAG_FLAG_IS_BINARY (1 << 1)
36 
37 static int ape_tag_read_field(AVFormatContext *s)
38 {
39  AVIOContext *pb = s->pb;
40  uint8_t key[1024], *value;
41  int64_t size, flags;
42  int i, c;
43 
44  size = avio_rl32(pb); /* field size */
45  flags = avio_rl32(pb); /* field flags */
46  for (i = 0; i < sizeof(key) - 1; i++) {
47  c = avio_r8(pb);
48  if (c < 0x20 || c > 0x7E)
49  break;
50  else
51  key[i] = c;
52  }
53  key[i] = 0;
54  if (c != 0) {
55  av_log(s, AV_LOG_WARNING, "Invalid APE tag key '%s'.\n", key);
56  return -1;
57  }
58  if (size > INT32_MAX - AV_INPUT_BUFFER_PADDING_SIZE) {
59  av_log(s, AV_LOG_ERROR, "APE tag size too large.\n");
60  return AVERROR_INVALIDDATA;
61  }
62  if (flags & APE_TAG_FLAG_IS_BINARY) {
63  uint8_t filename[1024];
64  enum AVCodecID id;
65  int ret;
66  AVStream *st = avformat_new_stream(s, NULL);
67  if (!st)
68  return AVERROR(ENOMEM);
69 
70  ret = avio_get_str(pb, size, filename, sizeof(filename));
71  if (ret < 0)
72  return ret;
73  if (size <= ret) {
74  av_log(s, AV_LOG_WARNING, "Skipping binary tag '%s'.\n", key);
75  return 0;
76  }
77  size -= ret;
78 
79  av_dict_set(&st->metadata, key, filename, 0);
80 
81  if ((id = ff_guess_image2_codec(filename)) != AV_CODEC_ID_NONE) {
82  int ret = ff_add_attached_pic(s, st, s->pb, NULL, size);
83  if (ret < 0) {
84  av_log(s, AV_LOG_ERROR, "Error reading cover art.\n");
85  return ret;
86  }
87  st->codecpar->codec_id = id;
88  } else {
89  if ((ret = ff_get_extradata(s, st->codecpar, s->pb, size)) < 0)
90  return ret;
91  st->codecpar->codec_type = AVMEDIA_TYPE_ATTACHMENT;
92  }
93  } else {
94  value = av_malloc(size+1);
95  if (!value)
96  return AVERROR(ENOMEM);
97  c = avio_read(pb, value, size);
98  if (c < 0) {
99  av_free(value);
100  return c;
101  }
102  value[c] = 0;
103  av_dict_set(&s->metadata, key, value, AV_DICT_DONT_STRDUP_VAL);
104  }
105  return 0;
106 }
107 
108 int64_t ff_ape_parse_tag(AVFormatContext *s)
109 {
110  AVIOContext *pb = s->pb;
111  int64_t file_size = avio_size(pb);
112  uint32_t val, fields, tag_bytes;
113  uint8_t buf[8];
114  int64_t tag_start;
115  int i;
116 
117  if (file_size < APE_TAG_FOOTER_BYTES)
118  return 0;
119 
120  avio_seek(pb, file_size - APE_TAG_FOOTER_BYTES, SEEK_SET);
121 
122  avio_read(pb, buf, 8); /* APETAGEX */
123  if (strncmp(buf, APE_TAG_PREAMBLE, 8)) {
124  return 0;
125  }
126 
127  val = avio_rl32(pb); /* APE tag version */
128  if (val > APE_TAG_VERSION) {
129  av_log(s, AV_LOG_ERROR, "Unsupported tag version. (>=%d)\n", APE_TAG_VERSION);
130  return 0;
131  }
132 
133  tag_bytes = avio_rl32(pb); /* tag size */
134  if (tag_bytes - APE_TAG_FOOTER_BYTES > (1024 * 1024 * 16)) {
135  av_log(s, AV_LOG_ERROR, "Tag size is way too big\n");
136  return 0;
137  }
138 
139  if (tag_bytes > file_size - APE_TAG_FOOTER_BYTES) {
140  av_log(s, AV_LOG_ERROR, "Invalid tag size %"PRIu32".\n", tag_bytes);
141  return 0;
142  }
143 
144  fields = avio_rl32(pb); /* number of fields */
145  if (fields > 65536) {
146  av_log(s, AV_LOG_ERROR, "Too many tag fields (%"PRIu32")\n", fields);
147  return 0;
148  }
149 
150  val = avio_rl32(pb); /* flags */
151  if (val & APE_TAG_FLAG_IS_HEADER) {
152  av_log(s, AV_LOG_ERROR, "APE Tag is a header\n");
153  return 0;
154  }
155 
156  avio_seek(pb, file_size - tag_bytes, SEEK_SET);
157 
158  if (val & APE_TAG_FLAG_CONTAINS_HEADER)
159  tag_bytes += APE_TAG_HEADER_BYTES;
160 
161  tag_start = file_size - tag_bytes;
162 
163  for (i=0; i<fields; i++)
164  if (ape_tag_read_field(s) < 0) break;
165 
166  return tag_start;
167 }
168 
169 static int string_is_ascii(const uint8_t *str)
170 {
171  while (*str && *str >= 0x20 && *str <= 0x7e ) str++;
172  return !*str;
173 }
174 
175 int ff_ape_write_tag(AVFormatContext *s)
176 {
177  AVDictionaryEntry *e = NULL;
178  int size, ret, count = 0;
179  AVIOContext *dyn_bc;
180  uint8_t *dyn_buf;
181 
182  if ((ret = avio_open_dyn_buf(&dyn_bc)) < 0)
183  return ret;
184 
185  ff_standardize_creation_time(s);
186  while ((e = av_dict_get(s->metadata, "", e, AV_DICT_IGNORE_SUFFIX))) {
187  int val_len;
188 
189  if (!string_is_ascii(e->key)) {
190  av_log(s, AV_LOG_WARNING, "Non ASCII keys are not allowed\n");
191  continue;
192  }
193 
194  val_len = strlen(e->value);
195  avio_wl32(dyn_bc, val_len); // value length
196  avio_wl32(dyn_bc, 0); // item flags
197  avio_put_str(dyn_bc, e->key); // key
198  avio_write(dyn_bc, e->value, val_len); // value
199  count++;
200  }
201  if (!count)
202  goto end;
203 
204  size = avio_get_dyn_buf(dyn_bc, &dyn_buf);
205  if (size <= 0)
206  goto end;
207  size += APE_TAG_FOOTER_BYTES;
208 
209  // header
210  avio_write(s->pb, "APETAGEX", 8); // id
211  avio_wl32(s->pb, APE_TAG_VERSION); // version
212  avio_wl32(s->pb, size);
213  avio_wl32(s->pb, count);
214 
215  // flags
216  avio_wl32(s->pb, APE_TAG_FLAG_CONTAINS_HEADER | APE_TAG_FLAG_IS_HEADER);
217  ffio_fill(s->pb, 0, 8); // reserved
218 
219  avio_write(s->pb, dyn_buf, size - APE_TAG_FOOTER_BYTES);
220 
221  // footer
222  avio_write(s->pb, "APETAGEX", 8); // id
223  avio_wl32(s->pb, APE_TAG_VERSION); // version
224  avio_wl32(s->pb, size); // size
225  avio_wl32(s->pb, count); // tag count
226 
227  // flags
228  avio_wl32(s->pb, APE_TAG_FLAG_CONTAINS_HEADER);
229  ffio_fill(s->pb, 0, 8); // reserved
230 
231 end:
232  ffio_free_dyn_buf(&dyn_bc);
233 
234  return ret;
235 }
AV_LOG_WARNING
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:186
AVERROR
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
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:724
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
ff_get_extradata
int ff_get_extradata(AVFormatContext *s, AVCodecParameters *par, AVIOContext *pb, int size)
Allocate extradata with additional AV_INPUT_BUFFER_PADDING_SIZE at end which is always set to 0 and f...
Definition: utils.c:469
apetag.h
ff_guess_image2_codec
enum AVCodecID ff_guess_image2_codec(const char *filename)
Definition: img2.c:106
AV_DICT_IGNORE_SUFFIX
#define AV_DICT_IGNORE_SUFFIX
Return first entry in a dictionary whose first part corresponds to the search key,...
Definition: dict.h:68
APE_TAG_FLAG_IS_BINARY
#define APE_TAG_FLAG_IS_BINARY
Definition: apetag.c:35
avio_size
int64_t avio_size(AVIOContext *s)
Get the filesize.
Definition: aviobuf.c:338
avio_get_dyn_buf
int avio_get_dyn_buf(AVIOContext *s, uint8_t **pbuffer)
Return the written size and a pointer to the buffer.
Definition: aviobuf.c:1411
APE_TAG_PREAMBLE
#define APE_TAG_PREAMBLE
Definition: apetag.h:28
ff_ape_parse_tag
int64_t ff_ape_parse_tag(AVFormatContext *s)
Read and parse an APE tag.
Definition: apetag.c:108
APE_TAG_VERSION
#define APE_TAG_VERSION
Definition: apetag.h:29
av_malloc
#define av_malloc(s)
Definition: tableprint_vlc.h:31
string_is_ascii
static int string_is_ascii(const uint8_t *str)
Definition: apetag.c:169
ape_tag_read_field
static int ape_tag_read_field(AVFormatContext *s)
Definition: apetag.c:37
val
static double val(void *priv, double ch)
Definition: aeval.c:76
APE_TAG_FLAG_CONTAINS_HEADER
#define APE_TAG_FLAG_CONTAINS_HEADER
Definition: apetag.c:32
AV_DICT_DONT_STRDUP_VAL
#define AV_DICT_DONT_STRDUP_VAL
Take ownership of a value that's been allocated with av_malloc() or another memory allocation functio...
Definition: dict.h:72
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
av_dict_get
AVDictionaryEntry * av_dict_get(const AVDictionary *m, const char *key, const AVDictionaryEntry *prev, int flags)
Get a dictionary entry with matching key.
Definition: dict.c:40
avio_open_dyn_buf
int avio_open_dyn_buf(AVIOContext **s)
Open a write only memory stream.
Definition: aviobuf.c:1399
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:257
AVDictionaryEntry::key
char * key
Definition: dict.h:80
key
const char * key
Definition: hwcontext_opencl.c:168
ff_ape_write_tag
int ff_ape_write_tag(AVFormatContext *s)
Write an APE tag into a file.
Definition: apetag.c:175
fields
the definition of that something depends on the semantic of the filter The callback must examine the status of the filter s links and proceed accordingly The status of output links is stored in the status_in and status_out fields and tested by the then the processing requires a frame on this link and the filter is expected to make efforts in that direction The status of input links is stored by the fifo and status_out fields
Definition: filter_design.txt:155
APE_TAG_FLAG_IS_HEADER
#define APE_TAG_FLAG_IS_HEADER
Definition: apetag.c:34
AVFormatContext
Format I/O context.
Definition: avformat.h:1097
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:992
NULL
#define NULL
Definition: coverity.c:32
AVStream::metadata
AVDictionary * metadata
Definition: avformat.h:903
ffio_fill
void ffio_fill(AVIOContext *s, int b, int64_t count)
Definition: aviobuf.c:204
c
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
AVCodecID
AVCodecID
Identify the syntax and semantics of the bitstream.
Definition: codec_id.h:47
avio_rl32
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:742
AVIOContext
Bytestream IO Context.
Definition: avio.h:161
id
enum AVCodecID id
Definition: extract_extradata_bsf.c:325
avio_get_str
int avio_get_str(AVIOContext *pb, int maxlen, char *buf, int buflen)
Read a string from pb into buf.
Definition: aviobuf.c:852
size
int size
Definition: twinvq_data.h:10344
avio_write
void avio_write(AVIOContext *s, const unsigned char *buf, int size)
Definition: aviobuf.c:218
avio_r8
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:616
avio_wl32
void avio_wl32(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:371
ff_standardize_creation_time
int ff_standardize_creation_time(AVFormatContext *s)
Standardize creation_time metadata in AVFormatContext to an ISO-8601 timestamp string.
Definition: utils.c:1827
i
int i
Definition: input.c:406
AV_CODEC_ID_NONE
@ AV_CODEC_ID_NONE
Definition: codec_id.h:48
avio_internal.h
value
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf default value
Definition: writing_filters.txt:86
AVMEDIA_TYPE_ATTACHMENT
@ AVMEDIA_TYPE_ATTACHMENT
Opaque data information usually sparse.
Definition: avutil.h:205
ffio_free_dyn_buf
void ffio_free_dyn_buf(AVIOContext **s)
Free a dynamic buffer.
Definition: aviobuf.c:1472
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:845
APE_TAG_HEADER_BYTES
#define APE_TAG_HEADER_BYTES
Definition: apetag.h:31
avio_seek
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:246
avformat.h
dict.h
AV_INPUT_BUFFER_PADDING_SIZE
#define AV_INPUT_BUFFER_PADDING_SIZE
Definition: defs.h:40
avio_read
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:625
APE_TAG_FOOTER_BYTES
#define APE_TAG_FOOTER_BYTES
Definition: apetag.h:30
av_free
#define av_free(p)
Definition: tableprint_vlc.h:34
AVDictionaryEntry
Definition: dict.h:79
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
av_dict_set
int av_dict_set(AVDictionary **pm, const char *key, const char *value, int flags)
Set the given entry in *pm, overwriting an existing entry.
Definition: dict.c:70
convert_header.str
string str
Definition: convert_header.py:20
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:561
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
AVDictionaryEntry::value
char * value
Definition: dict.h:81
avio_put_str
int avio_put_str(AVIOContext *s, const char *str)
Write a NULL-terminated string.
Definition: aviobuf.c:387
ff_add_attached_pic
int ff_add_attached_pic(AVFormatContext *s, AVStream *st, AVIOContext *pb, AVBufferRef **buf, int size)
Add an attached pic to an AVStream.
Definition: utils.c:250
Generated on Sat Sep 25 2021 19:22:01 for FFmpeg by   doxygen 1.8.17