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
37static int ape_tag_read_field(AVFormatContext *s)
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        AVStream *st = avformat_new_stream(s, NULL);
66        if (!st)
67            return AVERROR(ENOMEM);
68
69        size -= avio_get_str(pb, size, filename, sizeof(filename));
70        if (size <= 0) {
71            av_log(s, AV_LOG_WARNING, "Skipping binary tag '%s'.\n", key);
72            return 0;
73        }
74
75        av_dict_set(&st->metadata, key, filename, 0);
76
77        if ((id = ff_guess_image2_codec(filename)) != AV_CODEC_ID_NONE) {
78            AVPacket pkt;
79            int ret;
80
81            ret = av_get_packet(s->pb, &pkt, size);
82            if (ret < 0) {
83                av_log(s, AV_LOG_ERROR, "Error reading cover art.\n");
84                return ret;
85            }
86
87            st->disposition      |= AV_DISPOSITION_ATTACHED_PIC;
88            st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
89            st->codec->codec_id   = id;
90
91            st->attached_pic              = pkt;
92            st->attached_pic.stream_index = st->index;
93            st->attached_pic.flags       |= AV_PKT_FLAG_KEY;
94        } else {
95            if (ff_get_extradata(st->codec, s->pb, size) < 0)
96                return AVERROR(ENOMEM);
97            st->codec->codec_type = AVMEDIA_TYPE_ATTACHMENT;
98        }
99    } else {
100        value = av_malloc(size+1);
101        if (!value)
102            return AVERROR(ENOMEM);
103        c = avio_read(pb, value, size);
104        if (c < 0) {
105            av_free(value);
106            return c;
107        }
108        value[c] = 0;
109        av_dict_set(&s->metadata, key, value, AV_DICT_DONT_STRDUP_VAL);
110    }
111    return 0;
112}
113
114int64_t ff_ape_parse_tag(AVFormatContext *s)
115{
116    AVIOContext *pb = s->pb;
117    int64_t file_size = avio_size(pb);
118    uint32_t val, fields, tag_bytes;
119    uint8_t buf[8];
120    int64_t tag_start;
121    int i;
122
123    if (file_size < APE_TAG_FOOTER_BYTES)
124        return 0;
125
126    avio_seek(pb, file_size - APE_TAG_FOOTER_BYTES, SEEK_SET);
127
128    avio_read(pb, buf, 8);     /* APETAGEX */
129    if (strncmp(buf, APE_TAG_PREAMBLE, 8)) {
130        return 0;
131    }
132
133    val = avio_rl32(pb);       /* APE tag version */
134    if (val > APE_TAG_VERSION) {
135        av_log(s, AV_LOG_ERROR, "Unsupported tag version. (>=%d)\n", APE_TAG_VERSION);
136        return 0;
137    }
138
139    tag_bytes = avio_rl32(pb); /* tag size */
140    if (tag_bytes - APE_TAG_FOOTER_BYTES > (1024 * 1024 * 16)) {
141        av_log(s, AV_LOG_ERROR, "Tag size is way too big\n");
142        return 0;
143    }
144
145    if (tag_bytes > file_size - APE_TAG_FOOTER_BYTES) {
146        av_log(s, AV_LOG_ERROR, "Invalid tag size %"PRIu32".\n", tag_bytes);
147        return 0;
148    }
149    tag_start = file_size - tag_bytes - APE_TAG_FOOTER_BYTES;
150
151    fields = avio_rl32(pb);    /* number of fields */
152    if (fields > 65536) {
153        av_log(s, AV_LOG_ERROR, "Too many tag fields (%"PRIu32")\n", fields);
154        return 0;
155    }
156
157    val = avio_rl32(pb);       /* flags */
158    if (val & APE_TAG_FLAG_IS_HEADER) {
159        av_log(s, AV_LOG_ERROR, "APE Tag is a header\n");
160        return 0;
161    }
162
163    avio_seek(pb, file_size - tag_bytes, SEEK_SET);
164
165    for (i=0; i<fields; i++)
166        if (ape_tag_read_field(s) < 0) break;
167
168    return tag_start;
169}
170
171static int string_is_ascii(const uint8_t *str)
172{
173    while (*str && *str >= 0x20 && *str <= 0x7e ) str++;
174    return !*str;
175}
176
177int ff_ape_write_tag(AVFormatContext *s)
178{
179    AVDictionaryEntry *e = NULL;
180    int size, ret, count = 0;
181    AVIOContext *dyn_bc = NULL;
182    uint8_t *dyn_buf = NULL;
183
184    if ((ret = avio_open_dyn_buf(&dyn_bc)) < 0)
185        goto end;
186
187    // flags
188    avio_wl32(dyn_bc, APE_TAG_FLAG_CONTAINS_HEADER | APE_TAG_FLAG_CONTAINS_FOOTER |
189                     APE_TAG_FLAG_IS_HEADER);
190    ffio_fill(dyn_bc, 0, 8);             // reserved
191
192    while ((e = av_dict_get(s->metadata, "", e, AV_DICT_IGNORE_SUFFIX))) {
193        int val_len;
194
195        if (!string_is_ascii(e->key)) {
196            av_log(s, AV_LOG_WARNING, "Non ASCII keys are not allowed\n");
197            continue;
198        }
199
200        val_len = strlen(e->value);
201        avio_wl32(dyn_bc, val_len);            // value length
202        avio_wl32(dyn_bc, 0);                  // item flags
203        avio_put_str(dyn_bc, e->key);          // key
204        avio_write(dyn_bc, e->value, val_len); // value
205        count++;
206    }
207    if (!count)
208        goto end;
209
210    size = avio_close_dyn_buf(dyn_bc, &dyn_buf);
211    if (size <= 0)
212        goto end;
213    size += 20;
214
215    // header
216    avio_write(s->pb, "APETAGEX", 8);   // id
217    avio_wl32(s->pb, APE_TAG_VERSION);  // version
218    avio_wl32(s->pb, size);
219    avio_wl32(s->pb, count);
220
221    avio_write(s->pb, dyn_buf, size - 20);
222
223    // footer
224    avio_write(s->pb, "APETAGEX", 8);   // id
225    avio_wl32(s->pb, APE_TAG_VERSION);  // version
226    avio_wl32(s->pb, size);             // size
227    avio_wl32(s->pb, count);            // tag count
228
229    // flags
230    avio_wl32(s->pb, APE_TAG_FLAG_CONTAINS_HEADER | APE_TAG_FLAG_CONTAINS_FOOTER);
231    ffio_fill(s->pb, 0, 8);             // reserved
232
233end:
234    if (dyn_bc && !dyn_buf)
235        avio_close_dyn_buf(dyn_bc, &dyn_buf);
236    av_freep(&dyn_buf);
237
238    return ret;
239}
240