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apetag.c
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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 (1 << 31)
33 #define APE_TAG_FLAG_CONTAINS_FOOTER (1 << 30)
34 #define APE_TAG_FLAG_IS_HEADER (1 << 29)
35 #define APE_TAG_FLAG_IS_BINARY (1 << 1)
36 
38 {
39  AVIOContext *pb = s->pb;
40  uint8_t key[1024], *value;
41  uint32_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 - FF_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  AVPacket pkt;
83  int ret;
84 
85  ret = av_get_packet(s->pb, &pkt, size);
86  if (ret < 0) {
87  av_log(s, AV_LOG_ERROR, "Error reading cover art.\n");
88  return ret;
89  }
90 
93  st->codec->codec_id = id;
94 
95  st->attached_pic = pkt;
98  } else {
99  if (ff_get_extradata(st->codec, s->pb, size) < 0)
100  return AVERROR(ENOMEM);
102  }
103  } else {
104  value = av_malloc(size+1);
105  if (!value)
106  return AVERROR(ENOMEM);
107  c = avio_read(pb, value, size);
108  if (c < 0) {
109  av_free(value);
110  return c;
111  }
112  value[c] = 0;
113  av_dict_set(&s->metadata, key, value, AV_DICT_DONT_STRDUP_VAL);
114  }
115  return 0;
116 }
117 
119 {
120  AVIOContext *pb = s->pb;
121  int64_t file_size = avio_size(pb);
122  uint32_t val, fields, tag_bytes;
123  uint8_t buf[8];
124  int64_t tag_start;
125  int i;
126 
127  if (file_size < APE_TAG_FOOTER_BYTES)
128  return 0;
129 
130  avio_seek(pb, file_size - APE_TAG_FOOTER_BYTES, SEEK_SET);
131 
132  avio_read(pb, buf, 8); /* APETAGEX */
133  if (strncmp(buf, APE_TAG_PREAMBLE, 8)) {
134  return 0;
135  }
136 
137  val = avio_rl32(pb); /* APE tag version */
138  if (val > APE_TAG_VERSION) {
139  av_log(s, AV_LOG_ERROR, "Unsupported tag version. (>=%d)\n", APE_TAG_VERSION);
140  return 0;
141  }
142 
143  tag_bytes = avio_rl32(pb); /* tag size */
144  if (tag_bytes - APE_TAG_FOOTER_BYTES > (1024 * 1024 * 16)) {
145  av_log(s, AV_LOG_ERROR, "Tag size is way too big\n");
146  return 0;
147  }
148 
149  if (tag_bytes > file_size - APE_TAG_FOOTER_BYTES) {
150  av_log(s, AV_LOG_ERROR, "Invalid tag size %"PRIu32".\n", tag_bytes);
151  return 0;
152  }
153  tag_start = file_size - tag_bytes - APE_TAG_FOOTER_BYTES;
154 
155  fields = avio_rl32(pb); /* number of fields */
156  if (fields > 65536) {
157  av_log(s, AV_LOG_ERROR, "Too many tag fields (%"PRIu32")\n", fields);
158  return 0;
159  }
160 
161  val = avio_rl32(pb); /* flags */
162  if (val & APE_TAG_FLAG_IS_HEADER) {
163  av_log(s, AV_LOG_ERROR, "APE Tag is a header\n");
164  return 0;
165  }
166 
167  avio_seek(pb, file_size - tag_bytes, SEEK_SET);
168 
169  for (i=0; i<fields; i++)
170  if (ape_tag_read_field(s) < 0) break;
171 
172  return tag_start;
173 }
174 
175 static int string_is_ascii(const uint8_t *str)
176 {
177  while (*str && *str >= 0x20 && *str <= 0x7e ) str++;
178  return !*str;
179 }
180 
182 {
183  AVDictionaryEntry *e = NULL;
184  int size, ret, count = 0;
185  AVIOContext *dyn_bc = NULL;
186  uint8_t *dyn_buf = NULL;
187 
188  if ((ret = avio_open_dyn_buf(&dyn_bc)) < 0)
189  goto end;
190 
191  // flags
194  ffio_fill(dyn_bc, 0, 8); // reserved
195 
196  while ((e = av_dict_get(s->metadata, "", e, AV_DICT_IGNORE_SUFFIX))) {
197  int val_len;
198 
199  if (!string_is_ascii(e->key)) {
200  av_log(s, AV_LOG_WARNING, "Non ASCII keys are not allowed\n");
201  continue;
202  }
203 
204  val_len = strlen(e->value);
205  avio_wl32(dyn_bc, val_len); // value length
206  avio_wl32(dyn_bc, 0); // item flags
207  avio_put_str(dyn_bc, e->key); // key
208  avio_write(dyn_bc, e->value, val_len); // value
209  count++;
210  }
211  if (!count)
212  goto end;
213 
214  size = avio_close_dyn_buf(dyn_bc, &dyn_buf);
215  if (size <= 0)
216  goto end;
217  size += 20;
218 
219  // header
220  avio_write(s->pb, "APETAGEX", 8); // id
221  avio_wl32(s->pb, APE_TAG_VERSION); // version
222  avio_wl32(s->pb, size);
223  avio_wl32(s->pb, count);
224 
225  avio_write(s->pb, dyn_buf, size - 20);
226 
227  // footer
228  avio_write(s->pb, "APETAGEX", 8); // id
229  avio_wl32(s->pb, APE_TAG_VERSION); // version
230  avio_wl32(s->pb, size); // size
231  avio_wl32(s->pb, count); // tag count
232 
233  // flags
235  ffio_fill(s->pb, 0, 8); // reserved
236 
237 end:
238  if (dyn_bc && !dyn_buf)
239  avio_close_dyn_buf(dyn_bc, &dyn_buf);
240  av_freep(&dyn_buf);
241 
242  return ret;
243 }