segment: introduce segmented chain muxer
[libav.git] / libavformat / segment.c
1 /*
2 * Generic segmenter
3 * Copyright (c) 2011, 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 <strings.h>
23 #include <float.h>
24
25 #include "avformat.h"
26 #include "internal.h"
27
28 #include "libavutil/log.h"
29 #include "libavutil/opt.h"
30 #include "libavutil/avstring.h"
31 #include "libavutil/parseutils.h"
32 #include "libavutil/mathematics.h"
33
34 typedef struct {
35 const AVClass *class; /**< Class for private options. */
36 int number;
37 AVFormatContext *avf;
38 char *format; /**< Set by a private option. */
39 char *list; /**< Set by a private option. */
40 float time; /**< Set by a private option. */
41 int size; /**< Set by a private option. */
42 int64_t offset_time;
43 int64_t recording_time;
44 int has_video;
45 AVIOContext *pb;
46 } SegmentContext;
47
48 static int segment_start(AVFormatContext *s)
49 {
50 SegmentContext *c = s->priv_data;
51 AVFormatContext *oc = c->avf;
52 int err = 0;
53
54 if (av_get_frame_filename(oc->filename, sizeof(oc->filename),
55 s->filename, c->number++) < 0)
56 return AVERROR(EINVAL);
57
58 if ((err = avio_open2(&oc->pb, oc->filename, AVIO_FLAG_WRITE,
59 &s->interrupt_callback, NULL)) < 0)
60 return err;
61
62 if (!oc->priv_data && oc->oformat->priv_data_size > 0) {
63 oc->priv_data = av_mallocz(oc->oformat->priv_data_size);
64 if (!oc->priv_data) {
65 avio_close(oc->pb);
66 return AVERROR(ENOMEM);
67 }
68 if (oc->oformat->priv_class) {
69 *(const AVClass**)oc->priv_data = oc->oformat->priv_class;
70 av_opt_set_defaults(oc->priv_data);
71 }
72 }
73
74 if ((err = oc->oformat->write_header(oc)) < 0) {
75 goto fail;
76 }
77
78 return 0;
79
80 fail:
81 avio_close(oc->pb);
82 av_freep(&oc->priv_data);
83
84 return err;
85 }
86
87 static int segment_end(AVFormatContext *oc)
88 {
89 int ret = 0;
90
91 if (oc->oformat->write_trailer)
92 ret = oc->oformat->write_trailer(oc);
93
94 avio_close(oc->pb);
95 if (oc->oformat->priv_class)
96 av_opt_free(oc->priv_data);
97 av_freep(&oc->priv_data);
98
99 return ret;
100 }
101
102 static int seg_write_header(AVFormatContext *s)
103 {
104 SegmentContext *seg = s->priv_data;
105 AVFormatContext *oc;
106 int ret, i;
107
108 seg->number = 0;
109 seg->offset_time = 0;
110 seg->recording_time = seg->time * 1000000;
111
112 if (seg->list)
113 if ((ret = avio_open2(&seg->pb, seg->list, AVIO_FLAG_WRITE,
114 &s->interrupt_callback, NULL)) < 0)
115 return ret;
116
117 for (i = 0; i< s->nb_streams; i++)
118 seg->has_video +=
119 (s->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO);
120
121 if (seg->has_video > 1)
122 av_log(s, AV_LOG_WARNING,
123 "More than a single video stream present, "
124 "expect issues decoding it.\n");
125
126 oc = avformat_alloc_context();
127
128 if (!oc) {
129 ret = AVERROR(ENOMEM);
130 goto fail;
131 }
132
133 oc->oformat = av_guess_format(seg->format, s->filename, NULL);
134
135 if (!oc->oformat) {
136 ret = AVERROR_MUXER_NOT_FOUND;
137 goto fail;
138 }
139 if (oc->oformat->flags & AVFMT_NOFILE) {
140 av_log(s, AV_LOG_ERROR, "format %s not supported.\n",
141 oc->oformat->name);
142 ret = AVERROR(EINVAL);
143 goto fail;
144 }
145
146 seg->avf = oc;
147
148 oc->streams = s->streams;
149 oc->nb_streams = s->nb_streams;
150
151 if (av_get_frame_filename(oc->filename, sizeof(oc->filename),
152 s->filename, seg->number++) < 0) {
153 ret = AVERROR(EINVAL);
154 goto fail;
155 }
156
157 if ((ret = avio_open2(&oc->pb, oc->filename, AVIO_FLAG_WRITE,
158 &s->interrupt_callback, NULL)) < 0)
159 goto fail;
160
161 if ((ret = avformat_write_header(oc, NULL)) < 0) {
162 avio_close(oc->pb);
163 goto fail;
164 }
165
166 if (seg->list) {
167 avio_printf(seg->pb, "%s\n", oc->filename);
168 avio_flush(seg->pb);
169 }
170
171 fail:
172 if (ret) {
173 oc->streams = NULL;
174 oc->nb_streams = 0;
175 if (seg->list)
176 avio_close(seg->pb);
177 avformat_free_context(oc);
178 }
179 return ret;
180 }
181
182 static int seg_write_packet(AVFormatContext *s, AVPacket *pkt)
183 {
184 SegmentContext *seg = s->priv_data;
185 AVFormatContext *oc = seg->avf;
186 AVStream *st = oc->streams[pkt->stream_index];
187 int64_t end_pts = seg->recording_time * seg->number;
188 int ret;
189
190 if ((seg->has_video && st->codec->codec_type == AVMEDIA_TYPE_VIDEO) &&
191 av_compare_ts(pkt->pts, st->time_base,
192 end_pts, AV_TIME_BASE_Q) >= 0 &&
193 pkt->flags & AV_PKT_FLAG_KEY) {
194
195 av_log(s, AV_LOG_DEBUG, "Next segment starts at %d %"PRId64"\n",
196 pkt->stream_index, pkt->pts);
197
198 ret = segment_end(oc);
199
200 if (!ret)
201 ret = segment_start(s);
202
203 if (ret)
204 goto fail;
205
206 if (seg->list) {
207 avio_printf(seg->pb, "%s\n", oc->filename);
208 avio_flush(seg->pb);
209 if (!(seg->number % seg->size)) {
210 avio_close(seg->pb);
211 if ((ret = avio_open2(&seg->pb, seg->list, AVIO_FLAG_WRITE,
212 &s->interrupt_callback, NULL)) < 0)
213 goto fail;
214
215 }
216 }
217 }
218
219 ret = oc->oformat->write_packet(oc, pkt);
220
221 fail:
222 if (ret < 0) {
223 oc->streams = NULL;
224 oc->nb_streams = 0;
225 if (seg->list)
226 avio_close(seg->pb);
227 avformat_free_context(oc);
228 }
229
230 return ret;
231 }
232
233 static int seg_write_trailer(struct AVFormatContext *s)
234 {
235 SegmentContext *seg = s->priv_data;
236 AVFormatContext *oc = seg->avf;
237 int ret = segment_end(oc);
238 if (seg->list)
239 avio_close(seg->pb);
240 oc->streams = NULL;
241 oc->nb_streams = 0;
242 avformat_free_context(oc);
243 return ret;
244 }
245
246 #define OFFSET(x) offsetof(SegmentContext, x)
247 #define E AV_OPT_FLAG_ENCODING_PARAM
248 static const AVOption options[] = {
249 { "segment_format", "container format used for the segments", OFFSET(format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, E },
250 { "segment_time", "segment length in seconds", OFFSET(time), AV_OPT_TYPE_FLOAT, {.dbl = 2}, 0, FLT_MAX, E },
251 { "segment_list", "output the segment list", OFFSET(list), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, E },
252 { "segment_list_size", "maximum number of playlist entries", OFFSET(size), AV_OPT_TYPE_INT, {.dbl = 5}, 0, INT_MAX, E },
253 { NULL },
254 };
255
256 static const AVClass seg_class = {
257 .class_name = "segment muxer",
258 .item_name = av_default_item_name,
259 .option = options,
260 .version = LIBAVUTIL_VERSION_INT,
261 };
262
263
264 AVOutputFormat ff_segment_muxer = {
265 .name = "segment",
266 .long_name = NULL_IF_CONFIG_SMALL("segment muxer"),
267 .priv_data_size = sizeof(SegmentContext),
268 .flags = AVFMT_GLOBALHEADER | AVFMT_NOFILE,
269 .write_header = seg_write_header,
270 .write_packet = seg_write_packet,
271 .write_trailer = seg_write_trailer,
272 .priv_class = &seg_class,
273 };