mpjpeg: Initial implementation
[libav.git] / libavformat / mpjpegdec.c
1 /*
2 * Multipart JPEG format
3 * Copyright (c) 2015 Luca Barbato
4 *
5 * This file is part of Libav.
6 *
7 * Libav 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 * Libav 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 Libav; 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/avstring.h"
23
24 #include "avformat.h"
25 #include "internal.h"
26
27 static int get_line(AVIOContext *pb, char *line, int line_size)
28 {
29 int i = ff_get_line(pb, line, line_size);
30
31 if (i > 1 && line[i - 2] == '\r')
32 line[i - 2] = '\0';
33
34 if (pb->error)
35 return pb->error;
36
37 if (pb->eof_reached)
38 return AVERROR_EOF;
39
40 return 0;
41 }
42
43 static int split_tag_value(char **tag, char **value, char *line)
44 {
45 char *p = line;
46
47 while (*p != '\0' && *p != ':')
48 p++;
49 if (*p != ':')
50 return AVERROR_INVALIDDATA;
51
52 *p = '\0';
53 *tag = line;
54
55 p++;
56
57 while (av_isspace(*p))
58 p++;
59
60 *value = p;
61
62 return 0;
63 }
64
65 static int check_content_type(char *line)
66 {
67 char *tag, *value;
68 int ret = split_tag_value(&tag, &value, line);
69
70 if (ret < 0)
71 return ret;
72
73 if (av_strcasecmp(tag, "Content-type") ||
74 av_strcasecmp(value, "image/jpeg"))
75 return AVERROR_INVALIDDATA;
76
77 return 0;
78 }
79
80 static int mpjpeg_read_probe(AVProbeData *p)
81 {
82 AVIOContext *pb;
83 char line[128] = { 0 };
84 int ret = 0;
85
86 pb = avio_alloc_context(p->buf, p->buf_size, 0, NULL, NULL, NULL, NULL);
87 if (!pb)
88 return AVERROR(ENOMEM);
89
90 if (p->buf_size < 2 || p->buf[0] != '-' || p->buf[1] != '-')
91 return 0;
92
93 while (!pb->eof_reached) {
94 ret = get_line(pb, line, sizeof(line));
95 if (ret < 0)
96 break;
97
98 ret = check_content_type(line);
99 if (!ret) {
100 ret = AVPROBE_SCORE_MAX;
101 break;
102 }
103 }
104
105 av_free(pb);
106
107 return ret;
108 }
109
110 static int mpjpeg_read_header(AVFormatContext *s)
111 {
112 AVStream *st;
113 char boundary[70 + 2 + 1];
114 int64_t pos = avio_tell(s->pb);
115 int ret;
116
117
118 ret = get_line(s->pb, boundary, sizeof(boundary));
119 if (ret < 0)
120 return ret;
121
122 if (strncmp(boundary, "--", 2))
123 return AVERROR_INVALIDDATA;
124
125 st = avformat_new_stream(s, NULL);
126
127 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
128 st->codec->codec_id = AV_CODEC_ID_MJPEG;
129
130 avpriv_set_pts_info(st, 60, 1, 25);
131
132 avio_seek(s->pb, pos, SEEK_SET);
133
134 return 0;
135 }
136
137 static int parse_content_length(const char *value)
138 {
139 long int val = strtol(value, NULL, 10);
140
141 if (val == LONG_MIN || val == LONG_MAX)
142 return AVERROR(errno);
143 if (val > INT_MAX)
144 return AVERROR(ERANGE);
145 return val;
146 }
147
148 static int parse_multipart_header(AVFormatContext *s)
149 {
150 char line[128];
151 int found_content_type = 0;
152 int ret, size = -1;
153
154 ret = get_line(s->pb, line, sizeof(line));
155 if (ret < 0)
156 return ret;
157
158 if (strncmp(line, "--", 2))
159 return AVERROR_INVALIDDATA;
160
161 while (!s->pb->eof_reached) {
162 char *tag, *value;
163
164 ret = get_line(s->pb, line, sizeof(line));
165 if (ret < 0)
166 return ret;
167
168 if (line[0] == '\0')
169 break;
170
171 ret = split_tag_value(&tag, &value, line);
172 if (ret < 0)
173 return ret;
174
175 if (!av_strcasecmp(tag, "Content-type")) {
176 if (av_strcasecmp(value, "image/jpeg")) {
177 av_log(s, AV_LOG_ERROR,
178 "Unexpected %s : %s\n",
179 tag, value);
180 return AVERROR_INVALIDDATA;
181 } else
182 found_content_type = 1;
183 } else if (!av_strcasecmp(tag, "Content-Length")) {
184 size = parse_content_length(value);
185 if (size < 0)
186 return size;
187 }
188 }
189
190 if (!found_content_type || size < 0) {
191 return AVERROR_INVALIDDATA;
192 }
193
194 return size;
195 }
196
197 static int mpjpeg_read_packet(AVFormatContext *s, AVPacket *pkt)
198 {
199 int ret;
200 int size = parse_multipart_header(s);
201
202 if (size < 0)
203 return size;
204
205 ret = av_get_packet(s->pb, pkt, size);
206 if (ret < 0)
207 return ret;
208
209 // trailing empty line
210 avio_skip(s->pb, 2);
211
212 return 0;
213 }
214
215 AVInputFormat ff_mpjpeg_demuxer = {
216 .name = "mpjpeg",
217 .long_name = NULL_IF_CONFIG_SMALL("MIME multipart JPEG"),
218 .mime_type = "multipart/x-mixed-replace",
219 .extensions = "mjpg",
220 .read_probe = mpjpeg_read_probe,
221 .read_header = mpjpeg_read_header,
222 .read_packet = mpjpeg_read_packet,
223 };