summaryrefslogtreecommitdiffstats
path: root/libavformat/concat.c
blob: 416bbf5fc3bef1fcc36846f7c7fcc4194597836f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
/*
 * Concat URL protocol
 * Copyright (c) 2006 Steve Lhomme
 * Copyright (c) 2007 Wolfram Gloger
 * Copyright (c) 2010 Michele OrrĂ¹
 *
 * This file is part of Libav.
 *
 * Libav is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * Libav is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with Libav; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include "avformat.h"
#include "libavutil/avstring.h"
#include "libavutil/mem.h"
#include "url.h"

#define AV_CAT_SEPARATOR "|"

struct concat_nodes {
    URLContext *uc;                ///< node's URLContext
    int64_t     size;              ///< url filesize
};

struct concat_data {
    struct concat_nodes *nodes;    ///< list of nodes to concat
    size_t               length;   ///< number of cat'ed nodes
    size_t               current;  ///< index of currently read node
};

static av_cold int concat_close(URLContext *h)
{
    int err = 0;
    size_t i;
    struct concat_data  *data  = h->priv_data;
    struct concat_nodes *nodes = data->nodes;

    for (i = 0; i != data->length; i++)
        err |= ffurl_close(nodes[i].uc);

    av_freep(&data->nodes);

    return err < 0 ? -1 : 0;
}

static av_cold int concat_open(URLContext *h, const char *uri, int flags)
{
    char *node_uri = NULL;
    int err = 0;
    int64_t size;
    size_t  len, i;
    URLContext *uc;
    struct concat_data  *data = h->priv_data;
    struct concat_nodes *nodes;

    av_strstart(uri, "concat:", &uri);

    for (i = 0, len = 1; uri[i]; i++)
        if (uri[i] == *AV_CAT_SEPARATOR)
            /* integer overflow */
            if (++len == UINT_MAX / sizeof(*nodes)) {
                av_freep(&h->priv_data);
                return AVERROR(ENAMETOOLONG);
            }

    if (!(nodes = av_realloc(NULL, sizeof(*nodes) * len))) {
        return AVERROR(ENOMEM);
    } else
        data->nodes = nodes;

    /* handle input */
    if (!*uri)
        err = AVERROR(ENOENT);
    for (i = 0; *uri; i++) {
        /* parsing uri */
        len = strcspn(uri, AV_CAT_SEPARATOR);
        if ((err = av_reallocp(&node_uri, len + 1)) < 0)
            break;
        av_strlcpy(node_uri, uri, len+1);
        uri += len + strspn(uri+len, AV_CAT_SEPARATOR);

        /* creating URLContext */
        if ((err = ffurl_open(&uc, node_uri, flags,
                              &h->interrupt_callback, NULL)) < 0)
            break;

        /* creating size */
        if ((size = ffurl_size(uc)) < 0) {
            ffurl_close(uc);
            err = AVERROR(ENOSYS);
            break;
        }

        /* assembling */
        nodes[i].uc   = uc;
        nodes[i].size = size;
    }
    av_free(node_uri);
    data->length = i;

    if (err < 0)
        concat_close(h);
    else if ((err = av_reallocp(&nodes, data->length * sizeof(*nodes))) < 0)
        concat_close(h);
    else
        data->nodes = nodes;
    return err;
}

static int concat_read(URLContext *h, unsigned char *buf, int size)
{
    int result, total = 0;
    struct concat_data  *data  = h->priv_data;
    struct concat_nodes *nodes = data->nodes;
    size_t i = data->current;

    while (size > 0) {
        result = ffurl_read(nodes[i].uc, buf, size);
        if (result < 0)
            return total ? total : result;
        if (!result)
            if (i + 1 == data->length ||
                ffurl_seek(nodes[++i].uc, 0, SEEK_SET) < 0)
                break;
        total += result;
        buf   += result;
        size  -= result;
    }
    data->current = i;
    return total;
}

static int64_t concat_seek(URLContext *h, int64_t pos, int whence)
{
    int64_t result;
    struct concat_data  *data  = h->priv_data;
    struct concat_nodes *nodes = data->nodes;
    size_t i;

    switch (whence) {
    case SEEK_END:
        for (i = data->length - 1;
             i && pos < -nodes[i].size;
             i--)
            pos += nodes[i].size;
        break;
    case SEEK_CUR:
        /* get the absolute position */
        for (i = 0; i != data->current; i++)
            pos += nodes[i].size;
        pos += ffurl_seek(nodes[i].uc, 0, SEEK_CUR);
        whence = SEEK_SET;
        /* fall through with the absolute position */
    case SEEK_SET:
        for (i = 0; i != data->length - 1 && pos >= nodes[i].size; i++)
            pos -= nodes[i].size;
        break;
    default:
        return AVERROR(EINVAL);
    }

    result = ffurl_seek(nodes[i].uc, pos, whence);
    if (result >= 0) {
        data->current = i;
        while (i)
            result += nodes[--i].size;
    }
    return result;
}

URLProtocol ff_concat_protocol = {
    .name           = "concat",
    .url_open       = concat_open,
    .url_read       = concat_read,
    .url_seek       = concat_seek,
    .url_close      = concat_close,
    .priv_data_size = sizeof(struct concat_data),
};
OpenPOWER on IntegriCloud