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FFmpeg/libavformat/dashenc.c

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  1. /*

  2.  * MPEG-DASH ISO BMFF segmenter

  3.  * Copyright (c) 2014 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 "libavutil/avstring.h"

  28. #include "libavutil/intreadwrite.h"

  29. #include "libavutil/mathematics.h"

  30. #include "libavutil/opt.h"

  31. #include "libavutil/time_internal.h"

  32. 

  33. #include "avc.h"

  34. #include "avformat.h"

  35. #include "avio_internal.h"

  36. #include "internal.h"

  37. #include "isom.h"

  38. #include "os_support.h"

  39. #include "url.h"

  40. 

  41. typedef struct Segment {

  42.     char file[1024];

  43.     int64_t start_pos;

  44.     int range_length, index_length;

  45.     int64_t time;

  46.     int duration;

  47.     int n;

  48. } Segment;

  49. 

  50. typedef struct OutputStream {

  51.     AVFormatContext *ctx;

  52.     int ctx_inited;

  53.     uint8_t iobuf[32768];

  54.     URLContext *out;

  55.     int packets_written;

  56.     char initfile[1024];

  57.     int64_t init_start_pos;

  58.     int init_range_length;

  59.     int nb_segments, segments_size, segment_index;

  60.     Segment **segments;

  61.     int64_t first_dts, start_dts, end_dts;

  62.     char bandwidth_str[64];

  63. 

  64.     char codec_str[100];

  65. } OutputStream;

  66. 

  67. typedef struct DASHContext {

  68.     const AVClass *class;  /* Class for private options. */

  69.     int window_size;

  70.     int extra_window_size;

  71.     int min_seg_duration;

  72.     int remove_at_exit;

  73.     int use_template;

  74.     int use_timeline;

  75.     int single_file;

  76.     OutputStream *streams;

  77.     int has_video, has_audio;

  78.     int last_duration;

  79.     int total_duration;

  80.     char availability_start_time[100];

  81.     char dirname[1024];

  82. } DASHContext;

  83. 

  84. static int dash_write(void *opaque, uint8_t *buf, int buf_size)

  85. {

  86.     OutputStream *os = opaque;

  87.     if (os->out)

  88.         ffurl_write(os->out, buf, buf_size);

  89.     return buf_size;

  90. }

  91. 

  92. // RFC 6381

  93. static void set_codec_str(AVFormatContext *s, AVCodecContext *codec,

  94.                           char *str, int size)

  95. {

  96.     const AVCodecTag *tags[2] = { NULL, NULL };

  97.     uint32_t tag;

  98.     if (codec->codec_type == AVMEDIA_TYPE_VIDEO)

  99.         tags[0] = ff_codec_movvideo_tags;

  100.     else if (codec->codec_type == AVMEDIA_TYPE_AUDIO)

  101.         tags[0] = ff_codec_movaudio_tags;

  102.     else

  103.         return;

  104. 

  105.     tag = av_codec_get_tag(tags, codec->codec_id);

  106.     if (!tag)

  107.         return;

  108.     if (size < 5)

  109.         return;

  110. 

  111.     AV_WL32(str, tag);

  112.     str[4] = '\0';

  113.     if (!strcmp(str, "mp4a") || !strcmp(str, "mp4v")) {

  114.         uint32_t oti;

  115.         tags[0] = ff_mp4_obj_type;

  116.         oti = av_codec_get_tag(tags, codec->codec_id);

  117.         if (oti)

  118.             av_strlcatf(str, size, ".%02x", oti);

  119.         else

  120.             return;

  121. 

  122.         if (tag == MKTAG('m', 'p', '4', 'a')) {

  123.             if (codec->extradata_size >= 2) {

  124.                 int aot = codec->extradata[0] >> 3;

  125.                 if (aot == 31)

  126.                     aot = ((AV_RB16(codec->extradata) >> 5) & 0x3f) + 32;

  127.                 av_strlcatf(str, size, ".%d", aot);

  128.             }

  129.         } else if (tag == MKTAG('m', 'p', '4', 'v')) {

  130.             // Unimplemented, should output ProfileLevelIndication as a decimal number

  131.             av_log(s, AV_LOG_WARNING, "Incomplete RFC 6381 codec string for mp4v\n");

  132.         }

  133.     } else if (!strcmp(str, "avc1")) {

  134.         uint8_t *tmpbuf = NULL;

  135.         uint8_t *extradata = codec->extradata;

  136.         int extradata_size = codec->extradata_size;

  137.         if (!extradata_size)

  138.             return;

  139.         if (extradata[0] != 1) {

  140.             AVIOContext *pb;

  141.             if (avio_open_dyn_buf(&pb) < 0)

  142.                 return;

  143.             if (ff_isom_write_avcc(pb, extradata, extradata_size) < 0) {

  144.                 avio_close_dyn_buf(pb, &tmpbuf);

  145.                 av_free(tmpbuf);

  146.                 return;

  147.             }

  148.             extradata_size = avio_close_dyn_buf(pb, &extradata);

  149.             tmpbuf = extradata;

  150.         }

  151. 

  152.         if (extradata_size >= 4)

  153.             av_strlcatf(str, size, ".%02x%02x%02x",

  154.                         extradata[1], extradata[2], extradata[3]);

  155.         av_free(tmpbuf);

  156.     }

  157. }

  158. 

  159. static void dash_free(AVFormatContext *s)

  160. {

  161.     DASHContext *c = s->priv_data;

  162.     int i, j;

  163.     if (!c->streams)

  164.         return;

  165.     for (i = 0; i < s->nb_streams; i++) {

  166.         OutputStream *os = &c->streams[i];

  167.         if (os->ctx && os->ctx_inited)

  168.             av_write_trailer(os->ctx);

  169.         if (os->ctx && os->ctx->pb)

  170.             av_free(os->ctx->pb);

  171.         ffurl_close(os->out);

  172.         os->out =  NULL;

  173.         if (os->ctx)

  174.             avformat_free_context(os->ctx);

  175.         for (j = 0; j < os->nb_segments; j++)

  176.             av_free(os->segments[j]);

  177.         av_free(os->segments);

  178.     }

  179.     av_freep(&c->streams);

  180. }

  181. 

  182. static void output_segment_list(OutputStream *os, AVIOContext *out, DASHContext *c)

  183. {

  184.     int i, start_index = 0, start_number = 1;

  185.     if (c->window_size) {

  186.         start_index  = FFMAX(os->nb_segments   - c->window_size, 0);

  187.         start_number = FFMAX(os->segment_index - c->window_size, 1);

  188.     }

  189. 

  190.     if (c->use_template) {

  191.         int timescale = c->use_timeline ? os->ctx->streams[0]->time_base.den : AV_TIME_BASE;

  192.         avio_printf(out, "\t\t\t\t<SegmentTemplate timescale=\"%d\" ", timescale);

  193.         if (!c->use_timeline)

  194.             avio_printf(out, "duration=\"%d\" ", c->last_duration);

  195.         avio_printf(out, "initialization=\"init-stream$RepresentationID$.m4s\" media=\"chunk-stream$RepresentationID$-$Number%%05d$.m4s\" startNumber=\"%d\">\n", c->use_timeline ? start_number : 1);

  196.         if (c->use_timeline) {

  197.             avio_printf(out, "\t\t\t\t\t<SegmentTimeline>\n");

  198.             for (i = start_index; i < os->nb_segments; ) {

  199.                 Segment *seg = os->segments[i];

  200.                 int repeat = 0;

  201.                 avio_printf(out, "\t\t\t\t\t\t<S ");

  202.                 if (i == start_index)

  203.                     avio_printf(out, "t=\"%"PRId64"\" ", seg->time);

  204.                 avio_printf(out, "d=\"%d\" ", seg->duration);

  205.                 while (i + repeat + 1 < os->nb_segments && os->segments[i + repeat + 1]->duration == seg->duration)

  206.                     repeat++;

  207.                 if (repeat > 0)

  208.                     avio_printf(out, "r=\"%d\" ", repeat);

  209.                 avio_printf(out, "/>\n");

  210.                 i += 1 + repeat;

  211.             }

  212.             avio_printf(out, "\t\t\t\t\t</SegmentTimeline>\n");

  213.         }

  214.         avio_printf(out, "\t\t\t\t</SegmentTemplate>\n");

  215.     } else if (c->single_file) {

  216.         avio_printf(out, "\t\t\t\t<BaseURL>%s</BaseURL>\n", os->initfile);

  217.         avio_printf(out, "\t\t\t\t<SegmentList timescale=\"%d\" duration=\"%d\" startNumber=\"%d\">\n", AV_TIME_BASE, c->last_duration, start_number);

  218.         avio_printf(out, "\t\t\t\t\t<Initialization range=\"%"PRId64"-%"PRId64"\" />\n", os->init_start_pos, os->init_start_pos + os->init_range_length - 1);

  219.         for (i = start_index; i < os->nb_segments; i++) {

  220.             Segment *seg = os->segments[i];

  221.             avio_printf(out, "\t\t\t\t\t<SegmentURL mediaRange=\"%"PRId64"-%"PRId64"\" ", seg->start_pos, seg->start_pos + seg->range_length - 1);

  222.             if (seg->index_length)

  223.                 avio_printf(out, "indexRange=\"%"PRId64"-%"PRId64"\" ", seg->start_pos, seg->start_pos + seg->index_length - 1);

  224.             avio_printf(out, "/>\n");

  225.         }

  226.         avio_printf(out, "\t\t\t\t</SegmentList>\n");

  227.     } else {

  228.         avio_printf(out, "\t\t\t\t<SegmentList timescale=\"%d\" duration=\"%d\" startNumber=\"%d\">\n", AV_TIME_BASE, c->last_duration, start_number);

  229.         avio_printf(out, "\t\t\t\t\t<Initialization sourceURL=\"%s\" />\n", os->initfile);

  230.         for (i = start_index; i < os->nb_segments; i++) {

  231.             Segment *seg = os->segments[i];

  232.             avio_printf(out, "\t\t\t\t\t<SegmentURL media=\"%s\" />\n", seg->file);

  233.         }

  234.         avio_printf(out, "\t\t\t\t</SegmentList>\n");

  235.     }

  236. }

  237. 

  238. static char *xmlescape(const char *str) {

  239.     int outlen = strlen(str)*3/2 + 6;

  240.     char *out = av_realloc(NULL, outlen + 1);

  241.     int pos = 0;

  242.     if (!out)

  243.         return NULL;

  244.     for (; *str; str++) {

  245.         if (pos + 6 > outlen) {

  246.             char *tmp;

  247.             outlen = 2 * outlen + 6;

  248.             tmp = av_realloc(out, outlen + 1);

  249.             if (!tmp) {

  250.                 av_free(out);

  251.                 return NULL;

  252.             }

  253.             out = tmp;

  254.         }

  255.         if (*str == '&') {

  256.             memcpy(&out[pos], "&amp;", 5);

  257.             pos += 5;

  258.         } else if (*str == '<') {

  259.             memcpy(&out[pos], "&lt;", 4);

  260.             pos += 4;

  261.         } else if (*str == '>') {

  262.             memcpy(&out[pos], "&gt;", 4);

  263.             pos += 4;

  264.         } else if (*str == '\'') {

  265.             memcpy(&out[pos], "&apos;", 6);

  266.             pos += 6;

  267.         } else if (*str == '\"') {

  268.             memcpy(&out[pos], "&quot;", 6);

  269.             pos += 6;

  270.         } else {

  271.             out[pos++] = *str;

  272.         }

  273.     }

  274.     out[pos] = '\0';

  275.     return out;

  276. }

  277. 

  278. static void write_time(AVIOContext *out, int64_t time)

  279. {

  280.     int seconds = time / AV_TIME_BASE;

  281.     int fractions = time % AV_TIME_BASE;

  282.     int minutes = seconds / 60;

  283.     int hours = minutes / 60;

  284.     seconds %= 60;

  285.     minutes %= 60;

  286.     avio_printf(out, "PT");

  287.     if (hours)

  288.         avio_printf(out, "%dH", hours);

  289.     if (hours || minutes)

  290.         avio_printf(out, "%dM", minutes);

  291.     avio_printf(out, "%d.%dS", seconds, fractions / (AV_TIME_BASE / 10));

  292. }

  293. 

  294. static int write_manifest(AVFormatContext *s, int final)

  295. {

  296.     DASHContext *c = s->priv_data;

  297.     AVIOContext *out;

  298.     char temp_filename[1024];

  299.     const char *write_filename;

  300.     int ret, i;

  301.     AVDictionaryEntry *title = av_dict_get(s->metadata, "title", NULL, 0);

  302. 

  303.     snprintf(temp_filename, sizeof(temp_filename), "%s.tmp", s->filename);

  304.     write_filename = USE_RENAME_REPLACE ? temp_filename : s->filename;

  305.     ret = avio_open2(&out, write_filename, AVIO_FLAG_WRITE, &s->interrupt_callback, NULL);

  306.     if (ret < 0) {

  307.         av_log(s, AV_LOG_ERROR, "Unable to open %s for writing\n", write_filename);

  308.         return ret;

  309.     }

  310.     avio_printf(out, "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n");

  311.     avio_printf(out, "<MPD xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\"\n"

  312.                 "\txmlns=\"urn:mpeg:dash:schema:mpd:2011\"\n"

  313.                 "\txmlns:xlink=\"http://www.w3.org/1999/xlink\"\n"

  314.                 "\txsi:schemaLocation=\"urn:mpeg:DASH:schema:MPD:2011 http://standards.iso.org/ittf/PubliclyAvailableStandards/MPEG-DASH_schema_files/DASH-MPD.xsd\"\n"

  315.                 "\tprofiles=\"urn:mpeg:dash:profile:isoff-live:2011\"\n"

  316.                 "\ttype=\"%s\"\n", final ? "static" : "dynamic");

  317.     if (final) {

  318.         avio_printf(out, "\tmediaPresentationDuration=\"");

  319.         write_time(out, c->total_duration);

  320.         avio_printf(out, "\"\n");

  321.     } else {

  322.         int update_period = c->last_duration / AV_TIME_BASE;

  323.         if (c->use_template && !c->use_timeline)

  324.             update_period = 500;

  325.         avio_printf(out, "\tminimumUpdatePeriod=\"PT%dS\"\n", update_period);

  326.         avio_printf(out, "\tsuggestedPresentationDelay=\"PT%dS\"\n", c->last_duration / AV_TIME_BASE);

  327.         if (!c->availability_start_time[0] && s->nb_streams > 0 && c->streams[0].nb_segments > 0) {

  328.             time_t t = time(NULL);

  329.             struct tm *ptm, tmbuf;

  330.             ptm = gmtime_r(&t, &tmbuf);

  331.             if (ptm) {

  332.                 if (!strftime(c->availability_start_time, sizeof(c->availability_start_time),

  333.                               "%Y-%m-%dT%H:%M:%S", ptm))

  334.                     c->availability_start_time[0] = '\0';

  335.             }

  336.         }

  337.         if (c->availability_start_time[0])

  338.             avio_printf(out, "\tavailabilityStartTime=\"%s\"\n", c->availability_start_time);

  339.         if (c->window_size && c->use_template) {

  340.             avio_printf(out, "\ttimeShiftBufferDepth=\"");

  341.             write_time(out, c->last_duration * c->window_size);

  342.             avio_printf(out, "\"\n");

  343.         }

  344.     }

  345.     avio_printf(out, "\tminBufferTime=\"");

  346.     write_time(out, c->last_duration);

  347.     avio_printf(out, "\">\n");

  348.     avio_printf(out, "\t<ProgramInformation>\n");

  349.     if (title) {

  350.         char *escaped = xmlescape(title->value);

  351.         avio_printf(out, "\t\t<Title>%s</Title>\n", escaped);

  352.         av_free(escaped);

  353.     }

  354.     avio_printf(out, "\t</ProgramInformation>\n");

  355.     if (c->window_size && s->nb_streams > 0 && c->streams[0].nb_segments > 0 && !c->use_template) {

  356.         OutputStream *os = &c->streams[0];

  357.         int start_index = FFMAX(os->nb_segments - c->window_size, 0);

  358.         int64_t start_time = av_rescale_q(os->segments[start_index]->time, s->streams[0]->time_base, AV_TIME_BASE_Q);

  359.         avio_printf(out, "\t<Period start=\"");

  360.         write_time(out, start_time);

  361.         avio_printf(out, "\">\n");

  362.     } else {

  363.         avio_printf(out, "\t<Period start=\"PT0.0S\">\n");

  364.     }

  365. 

  366.     if (c->has_video) {

  367.         avio_printf(out, "\t\t<AdaptationSet id=\"video\" segmentAlignment=\"true\" bitstreamSwitching=\"true\">\n");

  368.         for (i = 0; i < s->nb_streams; i++) {

  369.             AVStream *st = s->streams[i];

  370.             OutputStream *os = &c->streams[i];

  371.             if (s->streams[i]->codec->codec_type != AVMEDIA_TYPE_VIDEO)

  372.                 continue;

  373.             avio_printf(out, "\t\t\t<Representation id=\"%d\" mimeType=\"video/mp4\" codecs=\"%s\"%s width=\"%d\" height=\"%d\">\n", i, os->codec_str, os->bandwidth_str, st->codec->width, st->codec->height);

  374.             output_segment_list(&c->streams[i], out, c);

  375.             avio_printf(out, "\t\t\t</Representation>\n");

  376.         }

  377.         avio_printf(out, "\t\t</AdaptationSet>\n");

  378.     }

  379.     if (c->has_audio) {

  380.         avio_printf(out, "\t\t<AdaptationSet id=\"audio\" segmentAlignment=\"true\" bitstreamSwitching=\"true\">\n");

  381.         for (i = 0; i < s->nb_streams; i++) {

  382.             AVStream *st = s->streams[i];

  383.             OutputStream *os = &c->streams[i];

  384.             if (s->streams[i]->codec->codec_type != AVMEDIA_TYPE_AUDIO)

  385.                 continue;

  386.             avio_printf(out, "\t\t\t<Representation id=\"%d\" mimeType=\"audio/mp4\" codecs=\"%s\"%s audioSamplingRate=\"%d\">\n", i, os->codec_str, os->bandwidth_str, st->codec->sample_rate);

  387.             avio_printf(out, "\t\t\t\t<AudioChannelConfiguration schemeIdUri=\"urn:mpeg:dash:23003:3:audio_channel_configuration:2011\" value=\"%d\" />\n", st->codec->channels);

  388.             output_segment_list(&c->streams[i], out, c);

  389.             avio_printf(out, "\t\t\t</Representation>\n");

  390.         }

  391.         avio_printf(out, "\t\t</AdaptationSet>\n");

  392.     }

  393.     avio_printf(out, "\t</Period>\n");

  394.     avio_printf(out, "</MPD>\n");

  395.     avio_flush(out);

  396.     avio_close(out);

  397.     return USE_RENAME_REPLACE ? ff_rename(temp_filename, s->filename, s) : 0;

  398. }

  399. 

  400. static int dash_write_header(AVFormatContext *s)

  401. {

  402.     DASHContext *c = s->priv_data;

  403.     int ret = 0, i;

  404.     AVOutputFormat *oformat;

  405.     char *ptr;

  406.     char basename[1024];

  407. 

  408.     if (c->single_file)

  409.         c->use_template = 0;

  410. 

  411.     av_strlcpy(c->dirname, s->filename, sizeof(c->dirname));

  412.     ptr = strrchr(c->dirname, '/');

  413.     if (ptr) {

  414.         av_strlcpy(basename, &ptr[1], sizeof(basename));

  415.         ptr[1] = '\0';

  416.     } else {

  417.         c->dirname[0] = '\0';

  418.         av_strlcpy(basename, s->filename, sizeof(basename));

  419.     }

  420. 

  421.     ptr = strrchr(basename, '.');

  422.     if (ptr)

  423.         *ptr = '\0';

  424. 

  425.     oformat = av_guess_format("mp4", NULL, NULL);

  426.     if (!oformat) {

  427.         ret = AVERROR_MUXER_NOT_FOUND;

  428.         goto fail;

  429.     }

  430. 

  431.     c->streams = av_mallocz(sizeof(*c->streams) * s->nb_streams);

  432.     if (!c->streams) {

  433.         ret = AVERROR(ENOMEM);

  434.         goto fail;

  435.     }

  436. 

  437.     for (i = 0; i < s->nb_streams; i++) {

  438.         OutputStream *os = &c->streams[i];

  439.         AVFormatContext *ctx;

  440.         AVStream *st;

  441.         AVDictionary *opts = NULL;

  442.         char filename[1024];

  443. 

  444.         int bit_rate = s->streams[i]->codec->bit_rate ?

  445.                        s->streams[i]->codec->bit_rate :

  446.                        s->streams[i]->codec->rc_max_rate;

  447.         if (bit_rate) {

  448.             snprintf(os->bandwidth_str, sizeof(os->bandwidth_str),

  449.                      " bandwidth=\"%d\"", bit_rate);

  450.         } else {

  451.             int level = s->strict_std_compliance >= FF_COMPLIANCE_STRICT ?

  452.                         AV_LOG_ERROR : AV_LOG_WARNING;

  453.             av_log(s, level, "No bit rate set for stream %d\n", i);

  454.             if (s->strict_std_compliance >= FF_COMPLIANCE_STRICT) {

  455.                 ret = AVERROR(EINVAL);

  456.                 goto fail;

  457.             }

  458.         }

  459. 

  460.         ctx = avformat_alloc_context();

  461.         if (!ctx) {

  462.             ret = AVERROR(ENOMEM);

  463.             goto fail;

  464.         }

  465.         os->ctx = ctx;

  466.         ctx->oformat = oformat;

  467.         ctx->interrupt_callback = s->interrupt_callback;

  468. 

  469.         if (!(st = avformat_new_stream(ctx, NULL))) {

  470.             ret = AVERROR(ENOMEM);

  471.             goto fail;

  472.         }

  473.         avcodec_copy_context(st->codec, s->streams[i]->codec);

  474.         st->sample_aspect_ratio = s->streams[i]->sample_aspect_ratio;

  475.         st->time_base = s->streams[i]->time_base;

  476.         ctx->avoid_negative_ts = s->avoid_negative_ts;

  477. 

  478.         ctx->pb = avio_alloc_context(os->iobuf, sizeof(os->iobuf), AVIO_FLAG_WRITE, os, NULL, dash_write, NULL);

  479.         if (!ctx->pb) {

  480.             ret = AVERROR(ENOMEM);

  481.             goto fail;

  482.         }

  483. 

  484.         if (c->single_file)

  485.             snprintf(os->initfile, sizeof(os->initfile), "%s-stream%d.m4s", basename, i);

  486.         else

  487.             snprintf(os->initfile, sizeof(os->initfile), "init-stream%d.m4s", i);

  488.         snprintf(filename, sizeof(filename), "%s%s", c->dirname, os->initfile);

  489.         ret = ffurl_open(&os->out, filename, AVIO_FLAG_WRITE, &s->interrupt_callback, NULL);

  490.         if (ret < 0)

  491.             goto fail;

  492.         os->init_start_pos = 0;

  493. 

  494.         av_dict_set(&opts, "movflags", "frag_custom+dash", 0);

  495.         if ((ret = avformat_write_header(ctx, &opts)) < 0) {

  496.              goto fail;

  497.         }

  498.         os->ctx_inited = 1;

  499.         avio_flush(ctx->pb);

  500.         av_dict_free(&opts);

  501. 

  502.         if (c->single_file) {

  503.             os->init_range_length = avio_tell(ctx->pb);

  504.         } else {

  505.             ffurl_close(os->out);

  506.             os->out = NULL;

  507.         }

  508. 

  509.         s->streams[i]->time_base = st->time_base;

  510.         // If the muxer wants to shift timestamps, request to have them shifted

  511.         // already before being handed to this muxer, so we don't have mismatches

  512.         // between the MPD and the actual segments.

  513.         s->avoid_negative_ts = ctx->avoid_negative_ts;

  514.         if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO)

  515.             c->has_video = 1;

  516.         else if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO)

  517.             c->has_audio = 1;

  518. 

  519.         set_codec_str(s, os->ctx->streams[0]->codec, os->codec_str, sizeof(os->codec_str));

  520.         os->first_dts = AV_NOPTS_VALUE;

  521.         os->segment_index = 1;

  522.     }

  523. 

  524.     if (!c->has_video && c->min_seg_duration <= 0) {

  525.         av_log(s, AV_LOG_WARNING, "no video stream and no min seg duration set\n");

  526.         ret = AVERROR(EINVAL);

  527.     }

  528.     ret = write_manifest(s, 0);

  529. 

  530. fail:

  531.     if (ret)

  532.         dash_free(s);

  533.     return ret;

  534. }

  535. 

  536. static int add_segment(OutputStream *os, const char *file,

  537.                        int64_t time, int duration,

  538.                        int64_t start_pos, int64_t range_length,

  539.                        int64_t index_length)

  540. {

  541.     int err;

  542.     Segment *seg;

  543.     if (os->nb_segments >= os->segments_size) {

  544.         os->segments_size = (os->segments_size + 1) * 2;

  545.         if ((err = av_reallocp(&os->segments, sizeof(*os->segments) *

  546.                                os->segments_size)) < 0) {

  547.             os->segments_size = 0;

  548.             os->nb_segments = 0;

  549.             return err;

  550.         }

  551.     }

  552.     seg = av_mallocz(sizeof(*seg));

  553.     if (!seg)

  554.         return AVERROR(ENOMEM);

  555.     av_strlcpy(seg->file, file, sizeof(seg->file));

  556.     seg->time = time;

  557.     seg->duration = duration;

  558.     seg->start_pos = start_pos;

  559.     seg->range_length = range_length;

  560.     seg->index_length = index_length;

  561.     os->segments[os->nb_segments++] = seg;

  562.     os->segment_index++;

  563.     return 0;

  564. }

  565. 

  566. static void write_styp(AVIOContext *pb)

  567. {

  568.     avio_wb32(pb, 24);

  569.     ffio_wfourcc(pb, "styp");

  570.     ffio_wfourcc(pb, "msdh");

  571.     avio_wb32(pb, 0); /* minor */

  572.     ffio_wfourcc(pb, "msdh");

  573.     ffio_wfourcc(pb, "msix");

  574. }

  575. 

  576. static void find_index_range(AVFormatContext *s, const char *dirname,

  577.                              const char *filename, int64_t pos,

  578.                              int *index_length)

  579. {

  580.     char full_path[1024];

  581.     uint8_t buf[8];

  582.     URLContext *fd;

  583.     int ret;

  584. 

  585.     snprintf(full_path, sizeof(full_path), "%s%s", dirname, filename);

  586.     ret = ffurl_open(&fd, full_path, AVIO_FLAG_READ, &s->interrupt_callback, NULL);

  587.     if (ret < 0)

  588.         return;

  589.     if (ffurl_seek(fd, pos, SEEK_SET) != pos) {

  590.         ffurl_close(fd);

  591.         return;

  592.     }

  593.     ret = ffurl_read(fd, buf, 8);

  594.     ffurl_close(fd);

  595.     if (ret < 8)

  596.         return;

  597.     if (AV_RL32(&buf[4]) != MKTAG('s', 'i', 'd', 'x'))

  598.         return;

  599.     *index_length = AV_RB32(&buf[0]);

  600. }

  601. 

  602. static int dash_flush(AVFormatContext *s, int final, int stream)

  603. {

  604.     DASHContext *c = s->priv_data;

  605.     int i, ret = 0;

  606.     int cur_flush_segment_index = 0;

  607.     if (stream >= 0)

  608.         cur_flush_segment_index = c->streams[stream].segment_index;

  609. 

  610.     for (i = 0; i < s->nb_streams; i++) {

  611.         OutputStream *os = &c->streams[i];

  612.         char filename[1024] = "", full_path[1024], temp_path[1024];

  613.         const char *write_path;

  614.         int64_t start_pos = avio_tell(os->ctx->pb);

  615.         int range_length, index_length = 0;

  616. 

  617.         if (!os->packets_written)

  618.             continue;

  619. 

  620.         // Flush the single stream that got a keyframe right now.

  621.         // Flush all audio streams as well, in sync with video keyframes,

  622.         // but not the other video streams.

  623.         if (stream >= 0 && i != stream) {

  624.             if (s->streams[i]->codec->codec_type != AVMEDIA_TYPE_AUDIO)

  625.                 continue;

  626.             // Make sure we don't flush audio streams multiple times, when

  627.             // all video streams are flushed one at a time.

  628.             if (c->has_video && os->segment_index > cur_flush_segment_index)

  629.                 continue;

  630.         }

  631. 

  632.         if (!c->single_file) {

  633.             snprintf(filename, sizeof(filename), "chunk-stream%d-%05d.m4s", i, os->segment_index);

  634.             snprintf(full_path, sizeof(full_path), "%s%s", c->dirname, filename);

  635.             snprintf(temp_path, sizeof(temp_path), "%s.tmp", full_path);

  636.             write_path = USE_RENAME_REPLACE ? temp_path : full_path;

  637.             ret = ffurl_open(&os->out, write_path, AVIO_FLAG_WRITE, &s->interrupt_callback, NULL);

  638.             if (ret < 0)

  639.                 break;

  640.             write_styp(os->ctx->pb);

  641.         }

  642.         av_write_frame(os->ctx, NULL);

  643.         avio_flush(os->ctx->pb);

  644.         os->packets_written = 0;

  645. 

  646.         range_length = avio_tell(os->ctx->pb) - start_pos;

  647.         if (c->single_file) {

  648.             find_index_range(s, c->dirname, os->initfile, start_pos, &index_length);

  649.         } else {

  650.             ffurl_close(os->out);

  651.             os->out = NULL;

  652.             ret = USE_RENAME_REPLACE ? ff_rename(temp_path, full_path, s) : 0;

  653.             if (ret < 0)

  654.                 break;

  655.         }

  656.         add_segment(os, filename, os->start_dts, os->end_dts - os->start_dts, start_pos, range_length, index_length);

  657.     }

  658. 

  659.     if (c->window_size || (final && c->remove_at_exit)) {

  660.         for (i = 0; i < s->nb_streams; i++) {

  661.             OutputStream *os = &c->streams[i];

  662.             int j;

  663.             int remove = os->nb_segments - c->window_size - c->extra_window_size;

  664.             if (final && c->remove_at_exit)

  665.                 remove = os->nb_segments;

  666.             if (remove > 0) {

  667.                 for (j = 0; j < remove; j++) {

  668.                     char filename[1024];

  669.                     snprintf(filename, sizeof(filename), "%s%s", c->dirname, os->segments[j]->file);

  670.                     unlink(filename);

  671.                     av_free(os->segments[j]);

  672.                 }

  673.                 os->nb_segments -= remove;

  674.                 memmove(os->segments, os->segments + remove, os->nb_segments * sizeof(*os->segments));

  675.             }

  676.         }

  677.     }

  678. 

  679.     if (ret >= 0)

  680.         ret = write_manifest(s, final);

  681.     return ret;

  682. }

  683. 

  684. static int dash_write_packet(AVFormatContext *s, AVPacket *pkt)

  685. {

  686.     DASHContext *c = s->priv_data;

  687.     AVStream *st = s->streams[pkt->stream_index];

  688.     OutputStream *os = &c->streams[pkt->stream_index];

  689.     int64_t seg_end_duration = (os->segment_index) * (int64_t) c->min_seg_duration;

  690.     int ret;

  691. 

  692.     // If forcing the stream to start at 0, the mp4 muxer will set the start

  693.     // timestamps to 0. Do the same here, to avoid mismatches in duration/timestamps.

  694.     if (os->first_dts == AV_NOPTS_VALUE &&

  695.         s->avoid_negative_ts == AVFMT_AVOID_NEG_TS_MAKE_ZERO) {

  696.         pkt->pts -= pkt->dts;

  697.         pkt->dts  = 0;

  698.     }

  699. 

  700.     if (os->first_dts == AV_NOPTS_VALUE)

  701.         os->first_dts = pkt->dts;

  702. 

  703.     if ((!c->has_video || st->codec->codec_type == AVMEDIA_TYPE_VIDEO) &&

  704.         pkt->flags & AV_PKT_FLAG_KEY && os->packets_written &&

  705.         av_compare_ts(pkt->dts - os->first_dts, st->time_base,

  706.                       seg_end_duration, AV_TIME_BASE_Q) >= 0) {

  707.         int64_t prev_duration = c->last_duration;

  708. 

  709.         c->last_duration = av_rescale_q(pkt->dts - os->start_dts,

  710.                                         st->time_base,

  711.                                         AV_TIME_BASE_Q);

  712.         c->total_duration = av_rescale_q(pkt->dts - os->first_dts,

  713.                                          st->time_base,

  714.                                          AV_TIME_BASE_Q);

  715. 

  716.         if ((!c->use_timeline || !c->use_template) && prev_duration) {

  717.             if (c->last_duration < prev_duration*9/10 ||

  718.                 c->last_duration > prev_duration*11/10) {

  719.                 av_log(s, AV_LOG_WARNING,

  720.                        "Segment durations differ too much, enable use_timeline "

  721.                        "and use_template, or keep a stricter keyframe interval\n");

  722.             }

  723.         }

  724. 

  725.         if ((ret = dash_flush(s, 0, pkt->stream_index)) < 0)

  726.             return ret;

  727.     }

  728. 

  729.     if (!os->packets_written)

  730.         os->start_dts = pkt->dts;

  731.     os->end_dts = pkt->dts + pkt->duration;

  732.     os->packets_written++;

  733.     return ff_write_chained(os->ctx, 0, pkt, s, 0);

  734. }

  735. 

  736. static int dash_write_trailer(AVFormatContext *s)

  737. {

  738.     DASHContext *c = s->priv_data;

  739. 

  740.     if (s->nb_streams > 0) {

  741.         OutputStream *os = &c->streams[0];

  742.         // If no segments have been written so far, try to do a crude

  743.         // guess of the segment duration

  744.         if (!c->last_duration)

  745.             c->last_duration = av_rescale_q(os->end_dts - os->start_dts,

  746.                                             s->streams[0]->time_base,

  747.                                             AV_TIME_BASE_Q);

  748.         c->total_duration = av_rescale_q(os->end_dts - os->first_dts,

  749.                                          s->streams[0]->time_base,

  750.                                          AV_TIME_BASE_Q);

  751.     }

  752.     dash_flush(s, 1, -1);

  753. 

  754.     if (c->remove_at_exit) {

  755.         char filename[1024];

  756.         int i;

  757.         for (i = 0; i < s->nb_streams; i++) {

  758.             OutputStream *os = &c->streams[i];

  759.             snprintf(filename, sizeof(filename), "%s%s", c->dirname, os->initfile);

  760.             unlink(filename);

  761.         }

  762.         unlink(s->filename);

  763.     }

  764. 

  765.     dash_free(s);

  766.     return 0;

  767. }

  768. 

  769. #define OFFSET(x) offsetof(DASHContext, x)

  770. #define E AV_OPT_FLAG_ENCODING_PARAM

  771. static const AVOption options[] = {

  772.     { "window_size", "number of segments kept in the manifest", OFFSET(window_size), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, E },

  773.     { "extra_window_size", "number of segments kept outside of the manifest before removing from disk", OFFSET(extra_window_size), AV_OPT_TYPE_INT, { .i64 = 5 }, 0, INT_MAX, E },

  774.     { "min_seg_duration", "minimum segment duration (in microseconds)", OFFSET(min_seg_duration), AV_OPT_TYPE_INT64, { .i64 = 5000000 }, 0, INT_MAX, E },

  775.     { "remove_at_exit", "remove all segments when finished", OFFSET(remove_at_exit), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, E },

  776.     { "use_template", "Use SegmentTemplate instead of SegmentList", OFFSET(use_template), AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 1, E },

  777.     { "use_timeline", "Use SegmentTimeline in SegmentTemplate", OFFSET(use_timeline), AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 1, E },

  778.     { "single_file", "Store all segments in one file, accessed using byte ranges", OFFSET(single_file), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, E },

  779.     { NULL },

  780. };

  781. 

  782. static const AVClass dash_class = {

  783.     .class_name = "dash muxer",

  784.     .item_name  = av_default_item_name,

  785.     .option     = options,

  786.     .version    = LIBAVUTIL_VERSION_INT,

  787. };

  788. 

  789. AVOutputFormat ff_dash_muxer = {

  790.     .name           = "dash",

  791.     .long_name      = NULL_IF_CONFIG_SMALL("DASH Muxer"),

  792.     .priv_data_size = sizeof(DASHContext),

  793.     .audio_codec    = AV_CODEC_ID_AAC,

  794.     .video_codec    = AV_CODEC_ID_H264,

  795.     .flags          = AVFMT_GLOBALHEADER | AVFMT_NOFILE | AVFMT_TS_NEGATIVE,

  796.     .write_header   = dash_write_header,

  797.     .write_packet   = dash_write_packet,

  798.     .write_trailer  = dash_write_trailer,

  799.     .codec_tag      = (const AVCodecTag* const []){ ff_mp4_obj_type, 0 },

  800.     .priv_class     = &dash_class,

  801. };