1/*
2 * Live smooth streaming fragmenter
3 * Copyright (c) 2012 Martin Storsjo
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 "config.h"
23#if HAVE_UNISTD_H
24#include <unistd.h>
25#endif
26
27#include "avformat.h"
28#include "internal.h"
29#include "mux.h"
30#include "os_support.h"
31#include "avc.h"
32#include "url.h"
33
34#include "libavutil/opt.h"
35#include "libavutil/avstring.h"
36#include "libavutil/mathematics.h"
37#include "libavutil/uuid.h"
38
39typedef struct Fragment {
40    int64_t start_time, duration;
41    int n;
42    int64_t start_pos, size;
43    char file[1024];
44    char infofile[1024];
45} Fragment;
46
47typedef struct OutputStream {
48    AVFormatContext *ctx;
49    URLContext *out;  // Current output stream where all output is written
50    URLContext *out2; // Auxiliary output stream where all output is also written
51    URLContext *tail_out; // The actual main output stream, if we're currently seeked back to write elsewhere
52    int64_t tail_pos, cur_pos, cur_start_pos;
53    int packets_written;
54    const char *stream_type_tag;
55    int nb_fragments, fragments_size, fragment_index;
56    Fragment **fragments;
57
58    const char *fourcc;
59    char *private_str;
60    int packet_size;
61    int audio_tag;
62    char dirname[1024];
63    uint8_t iobuf[32768];
64} OutputStream;
65
66typedef struct SmoothStreamingContext {
67    const AVClass *class;  /* Class for private options. */
68    int window_size;
69    int extra_window_size;
70    int lookahead_count;
71    int min_frag_duration;
72    int remove_at_exit;
73    OutputStream *streams;
74    int has_video, has_audio;
75    int nb_fragments;
76} SmoothStreamingContext;
77
78static int ism_write(void *opaque, uint8_t *buf, int buf_size)
79{
80    OutputStream *os = opaque;
81    if (os->out)
82        ffurl_write(os->out, buf, buf_size);
83    if (os->out2)
84        ffurl_write(os->out2, buf, buf_size);
85    os->cur_pos += buf_size;
86    if (os->cur_pos >= os->tail_pos)
87        os->tail_pos = os->cur_pos;
88    return buf_size;
89}
90
91static int64_t ism_seek(void *opaque, int64_t offset, int whence)
92{
93    OutputStream *os = opaque;
94    int i;
95    if (whence != SEEK_SET)
96        return AVERROR(ENOSYS);
97    if (os->tail_out) {
98        ffurl_closep(&os->out);
99        ffurl_closep(&os->out2);
100        os->out = os->tail_out;
101        os->tail_out = NULL;
102    }
103    if (offset >= os->cur_start_pos) {
104        if (os->out)
105            ffurl_seek(os->out, offset - os->cur_start_pos, SEEK_SET);
106        os->cur_pos = offset;
107        return offset;
108    }
109    for (i = os->nb_fragments - 1; i >= 0; i--) {
110        Fragment *frag = os->fragments[i];
111        if (offset >= frag->start_pos && offset < frag->start_pos + frag->size) {
112            int ret;
113            AVDictionary *opts = NULL;
114            os->tail_out = os->out;
115            av_dict_set(&opts, "truncate", "0", 0);
116            ret = ffurl_open_whitelist(&os->out, frag->file, AVIO_FLAG_WRITE,
117                                       &os->ctx->interrupt_callback, &opts, os->ctx->protocol_whitelist, os->ctx->protocol_blacklist, NULL);
118            av_dict_free(&opts);
119            if (ret < 0) {
120                os->out = os->tail_out;
121                os->tail_out = NULL;
122                return ret;
123            }
124            av_dict_set(&opts, "truncate", "0", 0);
125            ffurl_open_whitelist(&os->out2, frag->infofile, AVIO_FLAG_WRITE,
126                                 &os->ctx->interrupt_callback, &opts, os->ctx->protocol_whitelist, os->ctx->protocol_blacklist, NULL);
127            av_dict_free(&opts);
128            ffurl_seek(os->out, offset - frag->start_pos, SEEK_SET);
129            if (os->out2)
130                ffurl_seek(os->out2, offset - frag->start_pos, SEEK_SET);
131            os->cur_pos = offset;
132            return offset;
133        }
134    }
135    return AVERROR(EIO);
136}
137
138static void get_private_data(OutputStream *os)
139{
140    AVCodecParameters *par = os->ctx->streams[0]->codecpar;
141    uint8_t *ptr = par->extradata;
142    int size = par->extradata_size;
143    int i;
144    if (par->codec_id == AV_CODEC_ID_H264) {
145        ff_avc_write_annexb_extradata(ptr, &ptr, &size);
146        if (!ptr)
147            ptr = par->extradata;
148    }
149    if (!ptr)
150        return;
151    os->private_str = av_mallocz(2*size + 1);
152    if (!os->private_str)
153        goto fail;
154    for (i = 0; i < size; i++)
155        snprintf(&os->private_str[2*i], 3, "%02x", ptr[i]);
156fail:
157    if (ptr != par->extradata)
158        av_free(ptr);
159}
160
161static void ism_free(AVFormatContext *s)
162{
163    SmoothStreamingContext *c = s->priv_data;
164    int i, j;
165    if (!c->streams)
166        return;
167    for (i = 0; i < s->nb_streams; i++) {
168        OutputStream *os = &c->streams[i];
169        ffurl_closep(&os->out);
170        ffurl_closep(&os->out2);
171        ffurl_closep(&os->tail_out);
172        if (os->ctx && os->ctx->pb)
173            avio_context_free(&os->ctx->pb);
174        avformat_free_context(os->ctx);
175        av_freep(&os->private_str);
176        for (j = 0; j < os->nb_fragments; j++)
177            av_freep(&os->fragments[j]);
178        av_freep(&os->fragments);
179    }
180    av_freep(&c->streams);
181}
182
183static void output_chunk_list(OutputStream *os, AVIOContext *out, int final, int skip, int window_size)
184{
185    int removed = 0, i, start = 0;
186    if (os->nb_fragments <= 0)
187        return;
188    if (os->fragments[0]->n > 0)
189        removed = 1;
190    if (final)
191        skip = 0;
192    if (window_size)
193        start = FFMAX(os->nb_fragments - skip - window_size, 0);
194    for (i = start; i < os->nb_fragments - skip; i++) {
195        Fragment *frag = os->fragments[i];
196        if (!final || removed)
197            avio_printf(out, "<c t=\"%"PRIu64"\" d=\"%"PRIu64"\" />\n", frag->start_time, frag->duration);
198        else
199            avio_printf(out, "<c n=\"%d\" d=\"%"PRIu64"\" />\n", frag->n, frag->duration);
200    }
201}
202
203static int write_manifest(AVFormatContext *s, int final)
204{
205    SmoothStreamingContext *c = s->priv_data;
206    AVIOContext *out;
207    char filename[1024], temp_filename[1024];
208    int ret, i, video_chunks = 0, audio_chunks = 0, video_streams = 0, audio_streams = 0;
209    int64_t duration = 0;
210
211    snprintf(filename, sizeof(filename), "%s/Manifest", s->url);
212    snprintf(temp_filename, sizeof(temp_filename), "%s/Manifest.tmp", s->url);
213    ret = s->io_open(s, &out, temp_filename, AVIO_FLAG_WRITE, NULL);
214    if (ret < 0) {
215        av_log(s, AV_LOG_ERROR, "Unable to open %s for writing\n", temp_filename);
216        return ret;
217    }
218    avio_printf(out, "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n");
219    for (i = 0; i < s->nb_streams; i++) {
220        OutputStream *os = &c->streams[i];
221        if (os->nb_fragments > 0) {
222            Fragment *last = os->fragments[os->nb_fragments - 1];
223            duration = last->start_time + last->duration;
224        }
225        if (s->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
226            video_chunks = os->nb_fragments;
227            video_streams++;
228        } else {
229            audio_chunks = os->nb_fragments;
230            audio_streams++;
231        }
232    }
233    if (!final) {
234        duration = 0;
235        video_chunks = audio_chunks = 0;
236    }
237    if (c->window_size) {
238        video_chunks = FFMIN(video_chunks, c->window_size);
239        audio_chunks = FFMIN(audio_chunks, c->window_size);
240    }
241    avio_printf(out, "<SmoothStreamingMedia MajorVersion=\"2\" MinorVersion=\"0\" Duration=\"%"PRIu64"\"", duration);
242    if (!final)
243        avio_printf(out, " IsLive=\"true\" LookAheadFragmentCount=\"%d\" DVRWindowLength=\"0\"", c->lookahead_count);
244    avio_printf(out, ">\n");
245    if (c->has_video) {
246        int last = -1, index = 0;
247        avio_printf(out, "<StreamIndex Type=\"video\" QualityLevels=\"%d\" Chunks=\"%d\" Url=\"QualityLevels({bitrate})/Fragments(video={start time})\">\n", video_streams, video_chunks);
248        for (i = 0; i < s->nb_streams; i++) {
249            OutputStream *os = &c->streams[i];
250            if (s->streams[i]->codecpar->codec_type != AVMEDIA_TYPE_VIDEO)
251                continue;
252            last = i;
253            avio_printf(out, "<QualityLevel Index=\"%d\" Bitrate=\"%"PRId64"\" FourCC=\"%s\" MaxWidth=\"%d\" MaxHeight=\"%d\" CodecPrivateData=\"%s\" />\n", index, s->streams[i]->codecpar->bit_rate, os->fourcc, s->streams[i]->codecpar->width, s->streams[i]->codecpar->height, os->private_str);
254            index++;
255        }
256        output_chunk_list(&c->streams[last], out, final, c->lookahead_count, c->window_size);
257        avio_printf(out, "</StreamIndex>\n");
258    }
259    if (c->has_audio) {
260        int last = -1, index = 0;
261        avio_printf(out, "<StreamIndex Type=\"audio\" QualityLevels=\"%d\" Chunks=\"%d\" Url=\"QualityLevels({bitrate})/Fragments(audio={start time})\">\n", audio_streams, audio_chunks);
262        for (i = 0; i < s->nb_streams; i++) {
263            OutputStream *os = &c->streams[i];
264            if (s->streams[i]->codecpar->codec_type != AVMEDIA_TYPE_AUDIO)
265                continue;
266            last = i;
267            avio_printf(out, "<QualityLevel Index=\"%d\" Bitrate=\"%"PRId64"\" FourCC=\"%s\" SamplingRate=\"%d\" Channels=\"%d\" BitsPerSample=\"16\" PacketSize=\"%d\" AudioTag=\"%d\" CodecPrivateData=\"%s\" />\n",
268                        index, s->streams[i]->codecpar->bit_rate, os->fourcc, s->streams[i]->codecpar->sample_rate,
269                        s->streams[i]->codecpar->ch_layout.nb_channels, os->packet_size, os->audio_tag, os->private_str);
270            index++;
271        }
272        output_chunk_list(&c->streams[last], out, final, c->lookahead_count, c->window_size);
273        avio_printf(out, "</StreamIndex>\n");
274    }
275    avio_printf(out, "</SmoothStreamingMedia>\n");
276    avio_flush(out);
277    ff_format_io_close(s, &out);
278    return ff_rename(temp_filename, filename, s);
279}
280
281static int ism_write_header(AVFormatContext *s)
282{
283    SmoothStreamingContext *c = s->priv_data;
284    int ret = 0, i;
285    const AVOutputFormat *oformat;
286
287    if (mkdir(s->url, 0777) == -1 && errno != EEXIST) {
288        av_log(s, AV_LOG_ERROR, "mkdir failed\n");
289        return AVERROR(errno);
290    }
291
292    oformat = av_guess_format("ismv", NULL, NULL);
293    if (!oformat) {
294        return AVERROR_MUXER_NOT_FOUND;
295    }
296
297    c->streams = av_calloc(s->nb_streams, sizeof(*c->streams));
298    if (!c->streams) {
299        return AVERROR(ENOMEM);
300    }
301
302    for (i = 0; i < s->nb_streams; i++) {
303        OutputStream *os = &c->streams[i];
304        AVFormatContext *ctx;
305        AVStream *st;
306        AVDictionary *opts = NULL;
307
308        if (!s->streams[i]->codecpar->bit_rate) {
309            av_log(s, AV_LOG_WARNING, "No bit rate set for stream %d\n", i);
310            // create a tmp name for the directory of fragments
311            snprintf(os->dirname, sizeof(os->dirname), "%s/QualityLevels(Tmp_%d)", s->url, i);
312        } else {
313            snprintf(os->dirname, sizeof(os->dirname), "%s/QualityLevels(%"PRId64")", s->url, s->streams[i]->codecpar->bit_rate);
314        }
315
316        if (mkdir(os->dirname, 0777) == -1 && errno != EEXIST) {
317            av_log(s, AV_LOG_ERROR, "mkdir failed\n");
318            return AVERROR(errno);
319        }
320
321        os->ctx = ctx = avformat_alloc_context();
322        if (!ctx) {
323            return AVERROR(ENOMEM);
324        }
325        if ((ret = ff_copy_whiteblacklists(ctx, s)) < 0)
326            return ret;
327        ctx->oformat = oformat;
328        ctx->interrupt_callback = s->interrupt_callback;
329
330        if (!(st = avformat_new_stream(ctx, NULL))) {
331            return AVERROR(ENOMEM);
332        }
333        avcodec_parameters_copy(st->codecpar, s->streams[i]->codecpar);
334        st->sample_aspect_ratio = s->streams[i]->sample_aspect_ratio;
335        st->time_base = s->streams[i]->time_base;
336
337        ctx->pb = avio_alloc_context(os->iobuf, sizeof(os->iobuf), 1, os, NULL, ism_write, ism_seek);
338        if (!ctx->pb) {
339            return AVERROR(ENOMEM);
340        }
341
342        av_dict_set_int(&opts, "ism_lookahead", c->lookahead_count, 0);
343        av_dict_set(&opts, "movflags", "frag_custom", 0);
344        ret = avformat_write_header(ctx, &opts);
345        av_dict_free(&opts);
346        if (ret < 0) {
347             return ret;
348        }
349        avio_flush(ctx->pb);
350        s->streams[i]->time_base = st->time_base;
351        if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
352            c->has_video = 1;
353            os->stream_type_tag = "video";
354            if (st->codecpar->codec_id == AV_CODEC_ID_H264) {
355                os->fourcc = "H264";
356            } else if (st->codecpar->codec_id == AV_CODEC_ID_VC1) {
357                os->fourcc = "WVC1";
358            } else {
359                av_log(s, AV_LOG_ERROR, "Unsupported video codec\n");
360                return AVERROR(EINVAL);
361            }
362        } else {
363            c->has_audio = 1;
364            os->stream_type_tag = "audio";
365            if (st->codecpar->codec_id == AV_CODEC_ID_AAC) {
366                os->fourcc = "AACL";
367                os->audio_tag = 0xff;
368            } else if (st->codecpar->codec_id == AV_CODEC_ID_WMAPRO) {
369                os->fourcc = "WMAP";
370                os->audio_tag = 0x0162;
371            } else {
372                av_log(s, AV_LOG_ERROR, "Unsupported audio codec\n");
373                return AVERROR(EINVAL);
374            }
375            os->packet_size = st->codecpar->block_align ? st->codecpar->block_align : 4;
376        }
377        get_private_data(os);
378    }
379
380    if (!c->has_video && c->min_frag_duration <= 0) {
381        av_log(s, AV_LOG_WARNING, "no video stream and no min frag duration set\n");
382        return AVERROR(EINVAL);
383    }
384    ret = write_manifest(s, 0);
385    if (ret < 0)
386        return ret;
387
388    return 0;
389}
390
391static int parse_fragment(AVFormatContext *s, const char *filename, int64_t *start_ts, int64_t *duration, int64_t *moof_size, int64_t size)
392{
393    AVIOContext *in;
394    int ret;
395    uint32_t len;
396    if ((ret = s->io_open(s, &in, filename, AVIO_FLAG_READ, NULL)) < 0)
397        return ret;
398    ret = AVERROR(EIO);
399    *moof_size = avio_rb32(in);
400    if (*moof_size < 8 || *moof_size > size)
401        goto fail;
402    if (avio_rl32(in) != MKTAG('m','o','o','f'))
403        goto fail;
404    len = avio_rb32(in);
405    if (len > *moof_size)
406        goto fail;
407    if (avio_rl32(in) != MKTAG('m','f','h','d'))
408        goto fail;
409    avio_seek(in, len - 8, SEEK_CUR);
410    avio_rb32(in); /* traf size */
411    if (avio_rl32(in) != MKTAG('t','r','a','f'))
412        goto fail;
413    while (avio_tell(in) < *moof_size) {
414        uint32_t len = avio_rb32(in);
415        uint32_t tag = avio_rl32(in);
416        int64_t end = avio_tell(in) + len - 8;
417        if (len < 8 || len >= *moof_size)
418            goto fail;
419        if (tag == MKTAG('u','u','i','d')) {
420            static const AVUUID tfxd = {
421                0x6d, 0x1d, 0x9b, 0x05, 0x42, 0xd5, 0x44, 0xe6,
422                0x80, 0xe2, 0x14, 0x1d, 0xaf, 0xf7, 0x57, 0xb2
423            };
424            AVUUID uuid;
425            avio_read(in, uuid, 16);
426            if (av_uuid_equal(uuid, tfxd) && len >= 8 + 16 + 4 + 16) {
427                avio_seek(in, 4, SEEK_CUR);
428                *start_ts = avio_rb64(in);
429                *duration = avio_rb64(in);
430                ret = 0;
431                break;
432            }
433        }
434        avio_seek(in, end, SEEK_SET);
435    }
436fail:
437    ff_format_io_close(s, &in);
438    return ret;
439}
440
441static int add_fragment(OutputStream *os, const char *file, const char *infofile, int64_t start_time, int64_t duration, int64_t start_pos, int64_t size)
442{
443    int err;
444    Fragment *frag;
445    if (os->nb_fragments >= os->fragments_size) {
446        os->fragments_size = (os->fragments_size + 1) * 2;
447        if ((err = av_reallocp_array(&os->fragments, sizeof(*os->fragments),
448                               os->fragments_size)) < 0) {
449            os->fragments_size = 0;
450            os->nb_fragments = 0;
451            return err;
452        }
453    }
454    frag = av_mallocz(sizeof(*frag));
455    if (!frag)
456        return AVERROR(ENOMEM);
457    av_strlcpy(frag->file, file, sizeof(frag->file));
458    av_strlcpy(frag->infofile, infofile, sizeof(frag->infofile));
459    frag->start_time = start_time;
460    frag->duration = duration;
461    frag->start_pos = start_pos;
462    frag->size = size;
463    frag->n = os->fragment_index;
464    os->fragments[os->nb_fragments++] = frag;
465    os->fragment_index++;
466    return 0;
467}
468
469static int copy_moof(AVFormatContext *s, const char* infile, const char *outfile, int64_t size)
470{
471    AVIOContext *in, *out;
472    int ret = 0;
473    if ((ret = s->io_open(s, &in, infile, AVIO_FLAG_READ, NULL)) < 0)
474        return ret;
475    if ((ret = s->io_open(s, &out, outfile, AVIO_FLAG_WRITE, NULL)) < 0) {
476        ff_format_io_close(s, &in);
477        return ret;
478    }
479    while (size > 0) {
480        uint8_t buf[8192];
481        int n = FFMIN(size, sizeof(buf));
482        n = avio_read(in, buf, n);
483        if (n <= 0) {
484            ret = AVERROR(EIO);
485            break;
486        }
487        avio_write(out, buf, n);
488        size -= n;
489    }
490    avio_flush(out);
491    ff_format_io_close(s, &out);
492    ff_format_io_close(s, &in);
493    return ret;
494}
495
496static int ism_flush(AVFormatContext *s, int final)
497{
498    SmoothStreamingContext *c = s->priv_data;
499    int i, ret = 0;
500
501    for (i = 0; i < s->nb_streams; i++) {
502        OutputStream *os = &c->streams[i];
503        char filename[1024], target_filename[1024], header_filename[1024], curr_dirname[1024];
504        int64_t size;
505        int64_t start_ts, duration, moof_size;
506        if (!os->packets_written)
507            continue;
508
509        snprintf(filename, sizeof(filename), "%s/temp", os->dirname);
510        ret = ffurl_open_whitelist(&os->out, filename, AVIO_FLAG_WRITE, &s->interrupt_callback, NULL, s->protocol_whitelist, s->protocol_blacklist, NULL);
511        if (ret < 0)
512            break;
513        os->cur_start_pos = os->tail_pos;
514        av_write_frame(os->ctx, NULL);
515        avio_flush(os->ctx->pb);
516        os->packets_written = 0;
517        if (!os->out || os->tail_out)
518            return AVERROR(EIO);
519
520        ffurl_closep(&os->out);
521        size = os->tail_pos - os->cur_start_pos;
522        if ((ret = parse_fragment(s, filename, &start_ts, &duration, &moof_size, size)) < 0)
523            break;
524
525        if (!s->streams[i]->codecpar->bit_rate) {
526            int64_t bitrate = (int64_t) size * 8 * AV_TIME_BASE / av_rescale_q(duration, s->streams[i]->time_base, AV_TIME_BASE_Q);
527            if (!bitrate) {
528                av_log(s, AV_LOG_ERROR, "calculating bitrate got zero.\n");
529                ret = AVERROR(EINVAL);
530                return ret;
531            }
532
533            av_log(s, AV_LOG_DEBUG, "calculated bitrate: %"PRId64"\n", bitrate);
534            s->streams[i]->codecpar->bit_rate = bitrate;
535            memcpy(curr_dirname, os->dirname, sizeof(os->dirname));
536            snprintf(os->dirname, sizeof(os->dirname), "%s/QualityLevels(%"PRId64")", s->url, s->streams[i]->codecpar->bit_rate);
537            snprintf(filename, sizeof(filename), "%s/temp", os->dirname);
538
539            // rename the tmp folder back to the correct name since we now have the bitrate
540            if ((ret = ff_rename((const char*)curr_dirname,  os->dirname, s)) < 0)
541                return ret;
542        }
543
544        snprintf(header_filename, sizeof(header_filename), "%s/FragmentInfo(%s=%"PRIu64")", os->dirname, os->stream_type_tag, start_ts);
545        snprintf(target_filename, sizeof(target_filename), "%s/Fragments(%s=%"PRIu64")", os->dirname, os->stream_type_tag, start_ts);
546        copy_moof(s, filename, header_filename, moof_size);
547        ret = ff_rename(filename, target_filename, s);
548        if (ret < 0)
549            break;
550        add_fragment(os, target_filename, header_filename, start_ts, duration,
551                     os->cur_start_pos, size);
552    }
553
554    if (c->window_size || (final && c->remove_at_exit)) {
555        for (i = 0; i < s->nb_streams; i++) {
556            OutputStream *os = &c->streams[i];
557            int j;
558            int remove = os->nb_fragments - c->window_size - c->extra_window_size - c->lookahead_count;
559            if (final && c->remove_at_exit)
560                remove = os->nb_fragments;
561            if (remove > 0) {
562                for (j = 0; j < remove; j++) {
563                    unlink(os->fragments[j]->file);
564                    unlink(os->fragments[j]->infofile);
565                    av_freep(&os->fragments[j]);
566                }
567                os->nb_fragments -= remove;
568                memmove(os->fragments, os->fragments + remove, os->nb_fragments * sizeof(*os->fragments));
569            }
570            if (final && c->remove_at_exit)
571                rmdir(os->dirname);
572        }
573    }
574
575    if (ret >= 0)
576        ret = write_manifest(s, final);
577    return ret;
578}
579
580static int ism_write_packet(AVFormatContext *s, AVPacket *pkt)
581{
582    SmoothStreamingContext *c = s->priv_data;
583    AVStream *st = s->streams[pkt->stream_index];
584    FFStream *const sti = ffstream(st);
585    OutputStream *os = &c->streams[pkt->stream_index];
586    int64_t end_dts = (c->nb_fragments + 1) * (int64_t) c->min_frag_duration;
587    int ret;
588
589    if (sti->first_dts == AV_NOPTS_VALUE)
590        sti->first_dts = pkt->dts;
591
592    if ((!c->has_video || st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) &&
593        av_compare_ts(pkt->dts - sti->first_dts, st->time_base,
594                      end_dts, AV_TIME_BASE_Q) >= 0 &&
595        pkt->flags & AV_PKT_FLAG_KEY && os->packets_written) {
596
597        if ((ret = ism_flush(s, 0)) < 0)
598            return ret;
599        c->nb_fragments++;
600    }
601
602    os->packets_written++;
603    return ff_write_chained(os->ctx, 0, pkt, s, 0);
604}
605
606static int ism_write_trailer(AVFormatContext *s)
607{
608    SmoothStreamingContext *c = s->priv_data;
609    ism_flush(s, 1);
610
611    if (c->remove_at_exit) {
612        char filename[1024];
613        snprintf(filename, sizeof(filename), "%s/Manifest", s->url);
614        unlink(filename);
615        rmdir(s->url);
616    }
617
618    return 0;
619}
620
621#define OFFSET(x) offsetof(SmoothStreamingContext, x)
622#define E AV_OPT_FLAG_ENCODING_PARAM
623static const AVOption options[] = {
624    { "window_size", "number of fragments kept in the manifest", OFFSET(window_size), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, E },
625    { "extra_window_size", "number of fragments kept outside of the manifest before removing from disk", OFFSET(extra_window_size), AV_OPT_TYPE_INT, { .i64 = 5 }, 0, INT_MAX, E },
626    { "lookahead_count", "number of lookahead fragments", OFFSET(lookahead_count), AV_OPT_TYPE_INT, { .i64 = 2 }, 0, INT_MAX, E },
627    { "min_frag_duration", "minimum fragment duration (in microseconds)", OFFSET(min_frag_duration), AV_OPT_TYPE_INT64, { .i64 = 5000000 }, 0, INT_MAX, E },
628    { "remove_at_exit", "remove all fragments when finished", OFFSET(remove_at_exit), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, E },
629    { NULL },
630};
631
632static const AVClass ism_class = {
633    .class_name = "smooth streaming muxer",
634    .item_name  = av_default_item_name,
635    .option     = options,
636    .version    = LIBAVUTIL_VERSION_INT,
637};
638
639
640const AVOutputFormat ff_smoothstreaming_muxer = {
641    .name           = "smoothstreaming",
642    .long_name      = NULL_IF_CONFIG_SMALL("Smooth Streaming Muxer"),
643    .priv_data_size = sizeof(SmoothStreamingContext),
644    .audio_codec    = AV_CODEC_ID_AAC,
645    .video_codec    = AV_CODEC_ID_H264,
646    .flags          = AVFMT_GLOBALHEADER | AVFMT_NOFILE,
647    .write_header   = ism_write_header,
648    .write_packet   = ism_write_packet,
649    .write_trailer  = ism_write_trailer,
650    .deinit         = ism_free,
651    .priv_class     = &ism_class,
652};
653