1/*
2 * Apple HTTP Live Streaming segmenter
3 * Copyright (c) 2012, Luca Barbato
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg 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 * FFmpeg 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 FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22#include <float.h>
23#include <stdint.h>
24
25#include "libavutil/mathematics.h"
26#include "libavutil/parseutils.h"
27#include "libavutil/avstring.h"
28#include "libavutil/opt.h"
29#include "libavutil/log.h"
30
31#include "avformat.h"
32#include "internal.h"
33
34typedef struct ListEntry {
35    char  name[1024];
36    double   duration;
37    struct ListEntry *next;
38} ListEntry;
39
40typedef struct HLSContext {
41    const AVClass *class;  // Class for private options.
42    unsigned number;
43    int64_t sequence;
44    int64_t start_sequence;
45    AVOutputFormat *oformat;
46    AVFormatContext *avf;
47    float time;            // Set by a private option.
48    int  size;             // Set by a private option.
49    int  wrap;             // Set by a private option.
50    int64_t recording_time;
51    int has_video;
52    int64_t start_pts;
53    int64_t end_pts;
54    double duration;      // last segment duration computed so far, in seconds
55    int nb_entries;
56    ListEntry *list;
57    ListEntry *end_list;
58    char *basename;
59    char *baseurl;
60    AVIOContext *pb;
61} HLSContext;
62
63static int hls_mux_init(AVFormatContext *s)
64{
65    HLSContext *hls = s->priv_data;
66    AVFormatContext *oc;
67    int i;
68
69    hls->avf = oc = avformat_alloc_context();
70    if (!oc)
71        return AVERROR(ENOMEM);
72
73    oc->oformat            = hls->oformat;
74    oc->interrupt_callback = s->interrupt_callback;
75    av_dict_copy(&oc->metadata, s->metadata, 0);
76
77    for (i = 0; i < s->nb_streams; i++) {
78        AVStream *st;
79        if (!(st = avformat_new_stream(oc, NULL)))
80            return AVERROR(ENOMEM);
81        avcodec_copy_context(st->codec, s->streams[i]->codec);
82        st->sample_aspect_ratio = s->streams[i]->sample_aspect_ratio;
83    }
84
85    return 0;
86}
87
88static int append_entry(HLSContext *hls, double duration)
89{
90    ListEntry *en = av_malloc(sizeof(*en));
91
92    if (!en)
93        return AVERROR(ENOMEM);
94
95    av_strlcpy(en->name, av_basename(hls->avf->filename), sizeof(en->name));
96
97    en->duration = duration;
98    en->next     = NULL;
99
100    if (!hls->list)
101        hls->list = en;
102    else
103        hls->end_list->next = en;
104
105    hls->end_list = en;
106
107    if (hls->size && hls->nb_entries >= hls->size) {
108        en = hls->list;
109        hls->list = en->next;
110        av_free(en);
111    } else
112        hls->nb_entries++;
113
114    hls->sequence++;
115
116    return 0;
117}
118
119static void free_entries(HLSContext *hls)
120{
121    ListEntry *p = hls->list, *en;
122
123    while(p) {
124        en = p;
125        p = p->next;
126        av_free(en);
127    }
128}
129
130static int hls_window(AVFormatContext *s, int last)
131{
132    HLSContext *hls = s->priv_data;
133    ListEntry *en;
134    int target_duration = 0;
135    int ret = 0;
136    int64_t sequence = FFMAX(hls->start_sequence, hls->sequence - hls->nb_entries);
137
138    if ((ret = avio_open2(&hls->pb, s->filename, AVIO_FLAG_WRITE,
139                          &s->interrupt_callback, NULL)) < 0)
140        goto fail;
141
142    for (en = hls->list; en; en = en->next) {
143        if (target_duration < en->duration)
144            target_duration = ceil(en->duration);
145    }
146
147    avio_printf(hls->pb, "#EXTM3U\n");
148    avio_printf(hls->pb, "#EXT-X-VERSION:3\n");
149    avio_printf(hls->pb, "#EXT-X-TARGETDURATION:%d\n", target_duration);
150    avio_printf(hls->pb, "#EXT-X-MEDIA-SEQUENCE:%"PRId64"\n", sequence);
151
152    av_log(s, AV_LOG_VERBOSE, "EXT-X-MEDIA-SEQUENCE:%"PRId64"\n",
153           sequence);
154
155    for (en = hls->list; en; en = en->next) {
156        avio_printf(hls->pb, "#EXTINF:%f,\n", en->duration);
157        if (hls->baseurl)
158            avio_printf(hls->pb, "%s", hls->baseurl);
159        avio_printf(hls->pb, "%s\n", en->name);
160    }
161
162    if (last)
163        avio_printf(hls->pb, "#EXT-X-ENDLIST\n");
164
165fail:
166    avio_closep(&hls->pb);
167    return ret;
168}
169
170static int hls_start(AVFormatContext *s)
171{
172    HLSContext *c = s->priv_data;
173    AVFormatContext *oc = c->avf;
174    int err = 0;
175
176    if (av_get_frame_filename(oc->filename, sizeof(oc->filename),
177                              c->basename, c->wrap ? c->sequence % c->wrap : c->sequence) < 0) {
178        av_log(oc, AV_LOG_ERROR, "Invalid segment filename template '%s'\n", c->basename);
179        return AVERROR(EINVAL);
180    }
181    c->number++;
182
183    if ((err = avio_open2(&oc->pb, oc->filename, AVIO_FLAG_WRITE,
184                          &s->interrupt_callback, NULL)) < 0)
185        return err;
186
187    if (oc->oformat->priv_class && oc->priv_data)
188        av_opt_set(oc->priv_data, "mpegts_flags", "resend_headers", 0);
189
190    return 0;
191}
192
193static int hls_write_header(AVFormatContext *s)
194{
195    HLSContext *hls = s->priv_data;
196    int ret, i;
197    char *p;
198    const char *pattern = "%d.ts";
199    int basename_size = strlen(s->filename) + strlen(pattern) + 1;
200
201    hls->sequence       = hls->start_sequence;
202    hls->recording_time = hls->time * AV_TIME_BASE;
203    hls->start_pts      = AV_NOPTS_VALUE;
204
205    for (i = 0; i < s->nb_streams; i++)
206        hls->has_video +=
207            s->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO;
208
209    if (hls->has_video > 1)
210        av_log(s, AV_LOG_WARNING,
211               "More than a single video stream present, "
212               "expect issues decoding it.\n");
213
214    hls->oformat = av_guess_format("mpegts", NULL, NULL);
215
216    if (!hls->oformat) {
217        ret = AVERROR_MUXER_NOT_FOUND;
218        goto fail;
219    }
220
221    hls->basename = av_malloc(basename_size);
222
223    if (!hls->basename) {
224        ret = AVERROR(ENOMEM);
225        goto fail;
226    }
227
228    strcpy(hls->basename, s->filename);
229
230    p = strrchr(hls->basename, '.');
231
232    if (p)
233        *p = '\0';
234
235    av_strlcat(hls->basename, pattern, basename_size);
236
237    if ((ret = hls_mux_init(s)) < 0)
238        goto fail;
239
240    if ((ret = hls_start(s)) < 0)
241        goto fail;
242
243    if ((ret = avformat_write_header(hls->avf, NULL)) < 0)
244        return ret;
245
246
247fail:
248    if (ret) {
249        av_free(hls->basename);
250        if (hls->avf)
251            avformat_free_context(hls->avf);
252    }
253    return ret;
254}
255
256static int hls_write_packet(AVFormatContext *s, AVPacket *pkt)
257{
258    HLSContext *hls = s->priv_data;
259    AVFormatContext *oc = hls->avf;
260    AVStream *st = s->streams[pkt->stream_index];
261    int64_t end_pts = hls->recording_time * hls->number;
262    int is_ref_pkt = 1;
263    int ret, can_split = 1;
264
265    if (hls->start_pts == AV_NOPTS_VALUE) {
266        hls->start_pts = pkt->pts;
267        hls->end_pts   = pkt->pts;
268    }
269
270    if (hls->has_video) {
271        can_split = st->codec->codec_type == AVMEDIA_TYPE_VIDEO &&
272                    pkt->flags & AV_PKT_FLAG_KEY;
273        is_ref_pkt = st->codec->codec_type == AVMEDIA_TYPE_VIDEO;
274    }
275    if (pkt->pts == AV_NOPTS_VALUE)
276        is_ref_pkt = can_split = 0;
277
278    if (is_ref_pkt)
279        hls->duration = (double)(pkt->pts - hls->end_pts)
280                                   * st->time_base.num / st->time_base.den;
281
282    if (can_split && av_compare_ts(pkt->pts - hls->start_pts, st->time_base,
283                                   end_pts, AV_TIME_BASE_Q) >= 0) {
284        ret = append_entry(hls, hls->duration);
285        if (ret)
286            return ret;
287
288        hls->end_pts = pkt->pts;
289        hls->duration = 0;
290
291        av_write_frame(oc, NULL); /* Flush any buffered data */
292        avio_close(oc->pb);
293
294        ret = hls_start(s);
295
296        if (ret)
297            return ret;
298
299        oc = hls->avf;
300
301        if ((ret = hls_window(s, 0)) < 0)
302            return ret;
303    }
304
305    ret = ff_write_chained(oc, pkt->stream_index, pkt, s);
306
307    return ret;
308}
309
310static int hls_write_trailer(struct AVFormatContext *s)
311{
312    HLSContext *hls = s->priv_data;
313    AVFormatContext *oc = hls->avf;
314
315    av_write_trailer(oc);
316    avio_closep(&oc->pb);
317    avformat_free_context(oc);
318    av_free(hls->basename);
319    append_entry(hls, hls->duration);
320    hls_window(s, 1);
321
322    free_entries(hls);
323    avio_close(hls->pb);
324    return 0;
325}
326
327#define OFFSET(x) offsetof(HLSContext, x)
328#define E AV_OPT_FLAG_ENCODING_PARAM
329static const AVOption options[] = {
330    {"start_number",  "set first number in the sequence",        OFFSET(start_sequence),AV_OPT_TYPE_INT64,  {.i64 = 0},     0, INT64_MAX, E},
331    {"hls_time",      "set segment length in seconds",           OFFSET(time),    AV_OPT_TYPE_FLOAT,  {.dbl = 2},     0, FLT_MAX, E},
332    {"hls_list_size", "set maximum number of playlist entries",  OFFSET(size),    AV_OPT_TYPE_INT,    {.i64 = 5},     0, INT_MAX, E},
333    {"hls_wrap",      "set number after which the index wraps",  OFFSET(wrap),    AV_OPT_TYPE_INT,    {.i64 = 0},     0, INT_MAX, E},
334    {"hls_base_url",  "url to prepend to each playlist entry",   OFFSET(baseurl), AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,       E},
335    { NULL },
336};
337
338static const AVClass hls_class = {
339    .class_name = "hls muxer",
340    .item_name  = av_default_item_name,
341    .option     = options,
342    .version    = LIBAVUTIL_VERSION_INT,
343};
344
345
346AVOutputFormat ff_hls_muxer = {
347    .name           = "hls",
348    .long_name      = NULL_IF_CONFIG_SMALL("Apple HTTP Live Streaming"),
349    .extensions     = "m3u8",
350    .priv_data_size = sizeof(HLSContext),
351    .audio_codec    = AV_CODEC_ID_AAC,
352    .video_codec    = AV_CODEC_ID_H264,
353    .flags          = AVFMT_NOFILE | AVFMT_ALLOW_FLUSH,
354    .write_header   = hls_write_header,
355    .write_packet   = hls_write_packet,
356    .write_trailer  = hls_write_trailer,
357    .priv_class     = &hls_class,
358};
359