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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 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 "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. // See ISO/IEC 23009-1:2014 5.3.9.4.4

  42. typedef enum {

  43.     DASH_TMPL_ID_UNDEFINED = -1,

  44.     DASH_TMPL_ID_ESCAPE,

  45.     DASH_TMPL_ID_REP_ID,

  46.     DASH_TMPL_ID_NUMBER,

  47.     DASH_TMPL_ID_BANDWIDTH,

  48.     DASH_TMPL_ID_TIME,

  49. } DASHTmplId;

  50. 

  51. typedef struct Segment {

  52.     char file[1024];

  53.     int64_t start_pos;

  54.     int range_length, index_length;

  55.     int64_t time;

  56.     int duration;

  57.     int n;

  58. } Segment;

  59. 

  60. typedef struct OutputStream {

  61.     AVFormatContext *ctx;

  62.     int ctx_inited;

  63.     uint8_t iobuf[32768];

  64.     URLContext *out;

  65.     int packets_written;

  66.     char initfile[1024];

  67.     int64_t init_start_pos;

  68.     int init_range_length;

  69.     int nb_segments, segments_size, segment_index;

  70.     Segment **segments;

  71.     int64_t first_dts, start_dts, end_dts;

  72.     int bit_rate;

  73.     char bandwidth_str[64];

  74. 

  75.     char codec_str[100];

  76. } OutputStream;

  77. 

  78. typedef struct DASHContext {

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

  80.     int window_size;

  81.     int extra_window_size;

  82.     int min_seg_duration;

  83.     int remove_at_exit;

  84.     int use_template;

  85.     int use_timeline;

  86.     int single_file;

  87.     OutputStream *streams;

  88.     int has_video, has_audio;

  89.     int64_t last_duration;

  90.     int64_t total_duration;

  91.     char availability_start_time[100];

  92.     char dirname[1024];

  93.     const char *single_file_name;

  94.     const char *init_seg_name;

  95.     const char *media_seg_name;

  96. } DASHContext;

  97. 

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

  99. {

  100.     OutputStream *os = opaque;

  101.     if (os->out)

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

  103.     return buf_size;

  104. }

  105. 

  106. // RFC 6381

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

  108.                           char *str, int size)

  109. {

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

  111.     uint32_t tag;

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

  113.         tags[0] = ff_codec_movvideo_tags;

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

  115.         tags[0] = ff_codec_movaudio_tags;

  116.     else

  117.         return;

  118. 

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

  120.     if (!tag)

  121.         return;

  122.     if (size < 5)

  123.         return;

  124. 

  125.     AV_WL32(str, tag);

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

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

  128.         uint32_t oti;

  129.         tags[0] = ff_mp4_obj_type;

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

  131.         if (oti)

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

  133.         else

  134.             return;

  135. 

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

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

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

  139.                 if (aot == 31)

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

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

  142.             }

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

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

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

  146.         }

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

  148.         uint8_t *tmpbuf = NULL;

  149.         uint8_t *extradata = codec->extradata;

  150.         int extradata_size = codec->extradata_size;

  151.         if (!extradata_size)

  152.             return;

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

  154.             AVIOContext *pb;

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

  156.                 return;

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

  158.                 avio_close_dyn_buf(pb, &tmpbuf);

  159.                 av_free(tmpbuf);

  160.                 return;

  161.             }

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

  163.             tmpbuf = extradata;

  164.         }

  165. 

  166.         if (extradata_size >= 4)

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

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

  169.         av_free(tmpbuf);

  170.     }

  171. }

  172. 

  173. static void dash_free(AVFormatContext *s)

  174. {

  175.     DASHContext *c = s->priv_data;

  176.     int i, j;

  177.     if (!c->streams)

  178.         return;

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

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

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

  182.             av_write_trailer(os->ctx);

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

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

  185.         ffurl_close(os->out);

  186.         os->out =  NULL;

  187.         if (os->ctx)

  188.             avformat_free_context(os->ctx);

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

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

  191.         av_free(os->segments);

  192.     }

  193.     av_freep(&c->streams);

  194. }

  195. 

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

  197. {

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

  199.     if (c->window_size) {

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

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

  202.     }

  203. 

  204.     if (c->use_template) {

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

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

  207.         if (!c->use_timeline)

  208.             avio_printf(out, "duration=\"%"PRId64"\" ", c->last_duration);

  209.         avio_printf(out, "initialization=\"%s\" media=\"%s\" startNumber=\"%d\">\n", c->init_seg_name, c->media_seg_name, c->use_timeline ? start_number : 1);

  210.         if (c->use_timeline) {

  211.             int64_t cur_time = 0;

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

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

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

  215.                 int repeat = 0;

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

  217.                 if (i == start_index || seg->time != cur_time)

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

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

  220.                 while (i + repeat + 1 < os->nb_segments &&

  221.                        os->segments[i + repeat + 1]->duration == seg->duration &&

  222.                        os->segments[i + repeat + 1]->time == os->segments[i + repeat]->time + os->segments[i + repeat]->duration)

  223.                     repeat++;

  224.                 if (repeat > 0)

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

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

  227.                 i += 1 + repeat;

  228.                 cur_time += (1 + repeat) * seg->duration;

  229.             }

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

  231.         }

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

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

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

  235.         avio_printf(out, "\t\t\t\t<SegmentList timescale=\"%d\" duration=\"%"PRId64"\" startNumber=\"%d\">\n", AV_TIME_BASE, c->last_duration, start_number);

  236.         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);

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

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

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

  240.             if (seg->index_length)

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

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

  243.         }

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

  245.     } else {

  246.         avio_printf(out, "\t\t\t\t<SegmentList timescale=\"%d\" duration=\"%"PRId64"\" startNumber=\"%d\">\n", AV_TIME_BASE, c->last_duration, start_number);

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

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

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

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

  251.         }

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

  253.     }

  254. }

  255. 

  256. static DASHTmplId dash_read_tmpl_id(const char *identifier, char *format_tag,

  257.                                     size_t format_tag_size, const char **ptr) {

  258.     const char *next_ptr;

  259.     DASHTmplId id_type = DASH_TMPL_ID_UNDEFINED;

  260. 

  261.     if (av_strstart(identifier, "$$", &next_ptr)) {

  262.         id_type = DASH_TMPL_ID_ESCAPE;

  263.         *ptr = next_ptr;

  264.     } else if (av_strstart(identifier, "$RepresentationID$", &next_ptr)) {

  265.         id_type = DASH_TMPL_ID_REP_ID;

  266.         // default to basic format, as $RepresentationID$ identifiers

  267.         // are not allowed to have custom format-tags.

  268.         av_strlcpy(format_tag, "%d", format_tag_size);

  269.         *ptr = next_ptr;

  270.     } else { // the following identifiers may have an explicit format_tag

  271.         if (av_strstart(identifier, "$Number", &next_ptr))

  272.             id_type = DASH_TMPL_ID_NUMBER;

  273.         else if (av_strstart(identifier, "$Bandwidth", &next_ptr))

  274.             id_type = DASH_TMPL_ID_BANDWIDTH;

  275.         else if (av_strstart(identifier, "$Time", &next_ptr))

  276.             id_type = DASH_TMPL_ID_TIME;

  277.         else

  278.             id_type = DASH_TMPL_ID_UNDEFINED;

  279. 

  280.         // next parse the dash format-tag and generate a c-string format tag

  281.         // (next_ptr now points at the first '%' at the beginning of the format-tag)

  282.         if (id_type != DASH_TMPL_ID_UNDEFINED) {

  283.             const char *number_format = DASH_TMPL_ID_TIME ? "lld" : "d";

  284.             if (next_ptr[0] == '$') { // no dash format-tag

  285.                 snprintf(format_tag, format_tag_size, "%%%s", number_format);

  286.                 *ptr = &next_ptr[1];

  287.             } else {

  288.                 const char *width_ptr;

  289.                 // only tolerate single-digit width-field (i.e. up to 9-digit width)

  290.                 if (av_strstart(next_ptr, "%0", &width_ptr) &&

  291.                     av_isdigit(width_ptr[0]) &&

  292.                     av_strstart(&width_ptr[1], "d$", &next_ptr)) {

  293.                     // yes, we're using a format tag to build format_tag.

  294.                     snprintf(format_tag, format_tag_size, "%s%c%s", "%0", width_ptr[0], number_format);

  295.                     *ptr = next_ptr;

  296.                 } else {

  297.                     av_log(NULL, AV_LOG_WARNING, "Failed to parse format-tag beginning with %s. Expected either a "

  298.                                                  "closing '$' character or a format-string like '%%0[width]d', "

  299.                                                  "where width must be a single digit\n", next_ptr);

  300.                     id_type = DASH_TMPL_ID_UNDEFINED;

  301.                 }

  302.             }

  303.         }

  304.     }

  305.     return id_type;

  306. }

  307. 

  308. static void dash_fill_tmpl_params(char *dst, size_t buffer_size,

  309.                                   const char *template, int rep_id,

  310.                                   int number, int bit_rate,

  311.                                   int64_t time) {

  312.     int dst_pos = 0;

  313.     const char *t_cur = template;

  314.     while (dst_pos < buffer_size - 1 && *t_cur) {

  315.         char format_tag[7]; // May be "%d", "%0Xd", or "%0Xlld" (for $Time$), where X is in [0-9]

  316.         int n = 0;

  317.         DASHTmplId id_type;

  318.         const char *t_next = strchr(t_cur, '$'); // copy over everything up to the first '$' character

  319.         if (t_next) {

  320.             int num_copy_bytes = FFMIN(t_next - t_cur, buffer_size - dst_pos - 1);

  321.             av_strlcpy(&dst[dst_pos], t_cur, num_copy_bytes + 1);

  322.             // advance

  323.             dst_pos += num_copy_bytes;

  324.             t_cur = t_next;

  325.         } else { // no more DASH identifiers to substitute - just copy the rest over and break

  326.             av_strlcpy(&dst[dst_pos], t_cur, buffer_size - dst_pos);

  327.             break;

  328.         }

  329. 

  330.         if (dst_pos >= buffer_size - 1 || !*t_cur)

  331.             break;

  332. 

  333.         // t_cur is now pointing to a '$' character

  334.         id_type = dash_read_tmpl_id(t_cur, format_tag, sizeof(format_tag), &t_next);

  335.         switch (id_type) {

  336.         case DASH_TMPL_ID_ESCAPE:

  337.             av_strlcpy(&dst[dst_pos], "$", 2);

  338.             n = 1;

  339.             break;

  340.         case DASH_TMPL_ID_REP_ID:

  341.             n = snprintf(&dst[dst_pos], buffer_size - dst_pos, format_tag, rep_id);

  342.             break;

  343.         case DASH_TMPL_ID_NUMBER:

  344.             n = snprintf(&dst[dst_pos], buffer_size - dst_pos, format_tag, number);

  345.             break;

  346.         case DASH_TMPL_ID_BANDWIDTH:

  347.             n = snprintf(&dst[dst_pos], buffer_size - dst_pos, format_tag, bit_rate);

  348.             break;

  349.         case DASH_TMPL_ID_TIME:

  350.             n = snprintf(&dst[dst_pos], buffer_size - dst_pos, format_tag, time);

  351.             break;

  352.         case DASH_TMPL_ID_UNDEFINED:

  353.             // copy over one byte and advance

  354.             av_strlcpy(&dst[dst_pos], t_cur, 2);

  355.             n = 1;

  356.             t_next = &t_cur[1];

  357.             break;

  358.         }

  359.         // t_next points just past the processed identifier

  360.         // n is the number of bytes that were attempted to be written to dst

  361.         // (may have failed to write all because buffer_size).

  362. 

  363.         // advance

  364.         dst_pos += FFMIN(n, buffer_size - dst_pos - 1);

  365.         t_cur = t_next;

  366.     }

  367. }

  368. 

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

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

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

  372.     int pos = 0;

  373.     if (!out)

  374.         return NULL;

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

  376.         if (pos + 6 > outlen) {

  377.             char *tmp;

  378.             outlen = 2 * outlen + 6;

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

  380.             if (!tmp) {

  381.                 av_free(out);

  382.                 return NULL;

  383.             }

  384.             out = tmp;

  385.         }

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

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

  388.             pos += 5;

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

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

  391.             pos += 4;

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

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

  394.             pos += 4;

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

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

  397.             pos += 6;

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

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

  400.             pos += 6;

  401.         } else {

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

  403.         }

  404.     }

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

  406.     return out;

  407. }

  408. 

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

  410. {

  411.     int seconds = time / AV_TIME_BASE;

  412.     int fractions = time % AV_TIME_BASE;

  413.     int minutes = seconds / 60;

  414.     int hours = minutes / 60;

  415.     seconds %= 60;

  416.     minutes %= 60;

  417.     avio_printf(out, "PT");

  418.     if (hours)

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

  420.     if (hours || minutes)

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

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

  423. }

  424. 

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

  426. {

  427.     DASHContext *c = s->priv_data;

  428.     AVIOContext *out;

  429.     char temp_filename[1024];

  430.     int ret, i;

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

  432. 

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

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

  435.     if (ret < 0) {

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

  437.         return ret;

  438.     }

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

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

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

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

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

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

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

  446.     if (final) {

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

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

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

  450.     } else {

  451.         int64_t update_period = c->last_duration / AV_TIME_BASE;

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

  453.             update_period = 500;

  454.         avio_printf(out, "\tminimumUpdatePeriod=\"PT%"PRId64"S\"\n", update_period);

  455.         avio_printf(out, "\tsuggestedPresentationDelay=\"PT%"PRId64"S\"\n", c->last_duration / AV_TIME_BASE);

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

  457.             time_t t = time(NULL);

  458.             struct tm *ptm, tmbuf;

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

  460.             if (ptm) {

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

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

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

  464.             }

  465.         }

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

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

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

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

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

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

  472.         }

  473.     }

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

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

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

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

  478.     if (title) {

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

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

  481.         av_free(escaped);

  482.     }

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

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

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

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

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

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

  489.         write_time(out, start_time);

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

  491.     } else {

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

  493.     }

  494. 

  495.     if (c->has_video) {

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

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

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

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

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

  501.                 continue;

  502.             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);

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

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

  505.         }

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

  507.     }

  508.     if (c->has_audio) {

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

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

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

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

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

  514.                 continue;

  515.             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);

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

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

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

  519.         }

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

  521.     }

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

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

  524.     avio_flush(out);

  525.     avio_close(out);

  526.     return ff_rename(temp_filename, s->filename);

  527. }

  528. 

  529. static int dash_write_header(AVFormatContext *s)

  530. {

  531.     DASHContext *c = s->priv_data;

  532.     int ret = 0, i;

  533.     AVOutputFormat *oformat;

  534.     char *ptr;

  535.     char basename[1024];

  536. 

  537.     if (c->single_file_name)

  538.         c->single_file = 1;

  539.     if (c->single_file)

  540.         c->use_template = 0;

  541. 

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

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

  544.     if (ptr) {

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

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

  547.     } else {

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

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

  550.     }

  551. 

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

  553.     if (ptr)

  554.         *ptr = '\0';

  555. 

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

  557.     if (!oformat) {

  558.         ret = AVERROR_MUXER_NOT_FOUND;

  559.         goto fail;

  560.     }

  561. 

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

  563.     if (!c->streams) {

  564.         ret = AVERROR(ENOMEM);

  565.         goto fail;

  566.     }

  567. 

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

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

  570.         AVFormatContext *ctx;

  571.         AVStream *st;

  572.         AVDictionary *opts = NULL;

  573.         char filename[1024];

  574. 

  575.         os->bit_rate = s->streams[i]->codec->bit_rate;

  576.         if (os->bit_rate) {

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

  578.                      " bandwidth=\"%d\"", os->bit_rate);

  579.         } else {

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

  581.                         AV_LOG_ERROR : AV_LOG_WARNING;

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

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

  584.                 ret = AVERROR(EINVAL);

  585.                 goto fail;

  586.             }

  587.         }

  588. 

  589.         ctx = avformat_alloc_context();

  590.         if (!ctx) {

  591.             ret = AVERROR(ENOMEM);

  592.             goto fail;

  593.         }

  594.         os->ctx = ctx;

  595.         ctx->oformat = oformat;

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

  597. 

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

  599.             ret = AVERROR(ENOMEM);

  600.             goto fail;

  601.         }

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

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

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

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

  606. 

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

  608.         if (!ctx->pb) {

  609.             ret = AVERROR(ENOMEM);

  610.             goto fail;

  611.         }

  612. 

  613.         if (c->single_file) {

  614.             if (c->single_file_name)

  615.                 dash_fill_tmpl_params(os->initfile, sizeof(os->initfile), c->single_file_name, i, 0, os->bit_rate, 0);

  616.             else

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

  618.         } else {

  619.             dash_fill_tmpl_params(os->initfile, sizeof(os->initfile), c->init_seg_name, i, 0, os->bit_rate, 0);

  620.         }

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

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

  623.         if (ret < 0)

  624.             goto fail;

  625.         os->init_start_pos = 0;

  626. 

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

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

  629.              goto fail;

  630.         }

  631.         os->ctx_inited = 1;

  632.         avio_flush(ctx->pb);

  633.         av_dict_free(&opts);

  634. 

  635.         if (c->single_file) {

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

  637.         } else {

  638.             ffurl_close(os->out);

  639.             os->out = NULL;

  640.         }

  641.         av_log(s, AV_LOG_VERBOSE, "Representation %d init segment written to: %s\n", i, filename);

  642. 

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

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

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

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

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

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

  649.             c->has_video = 1;

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

  651.             c->has_audio = 1;

  652. 

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

  654.         os->first_dts = AV_NOPTS_VALUE;

  655.         os->end_dts = AV_NOPTS_VALUE;

  656.         os->segment_index = 1;

  657.     }

  658. 

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

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

  661.         ret = AVERROR(EINVAL);

  662.     }

  663.     ret = write_manifest(s, 0);

  664.     if (!ret)

  665.         av_log(s, AV_LOG_VERBOSE, "Manifest written to: %s\n", s->filename);

  666. 

  667. fail:

  668.     if (ret)

  669.         dash_free(s);

  670.     return ret;

  671. }

  672. 

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

  674.                        int64_t time, int duration,

  675.                        int64_t start_pos, int64_t range_length,

  676.                        int64_t index_length)

  677. {

  678.     int err;

  679.     Segment *seg;

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

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

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

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

  684.             os->segments_size = 0;

  685.             os->nb_segments = 0;

  686.             return err;

  687.         }

  688.     }

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

  690.     if (!seg)

  691.         return AVERROR(ENOMEM);

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

  693.     seg->time = time;

  694.     seg->duration = duration;

  695.     seg->start_pos = start_pos;

  696.     seg->range_length = range_length;

  697.     seg->index_length = index_length;

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

  699.     os->segment_index++;

  700.     return 0;

  701. }

  702. 

  703. static void write_styp(AVIOContext *pb)

  704. {

  705.     avio_wb32(pb, 24);

  706.     ffio_wfourcc(pb, "styp");

  707.     ffio_wfourcc(pb, "msdh");

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

  709.     ffio_wfourcc(pb, "msdh");

  710.     ffio_wfourcc(pb, "msix");

  711. }

  712. 

  713. static void find_index_range(AVFormatContext *s, const char *full_path,

  714.                              int64_t pos, int *index_length)

  715. {

  716.     uint8_t buf[8];

  717.     URLContext *fd;

  718.     int ret;

  719. 

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

  721.     if (ret < 0)

  722.         return;

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

  724.         ffurl_close(fd);

  725.         return;

  726.     }

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

  728.     ffurl_close(fd);

  729.     if (ret < 8)

  730.         return;

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

  732.         return;

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

  734. }

  735. 

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

  737. {

  738.     DASHContext *c = s->priv_data;

  739.     int i, ret = 0;

  740.     int cur_flush_segment_index = 0;

  741.     if (stream >= 0)

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

  743. 

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

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

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

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

  748.         int range_length, index_length = 0;

  749. 

  750.         if (!os->packets_written)

  751.             continue;

  752. 

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

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

  755.         // but not the other video streams.

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

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

  758.                 continue;

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

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

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

  762.                 continue;

  763.         }

  764. 

  765.         if (!c->single_file) {

  766.             dash_fill_tmpl_params(filename, sizeof(filename), c->media_seg_name, i, os->segment_index, os->bit_rate, os->start_dts);

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

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

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

  770.             if (ret < 0)

  771.                 break;

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

  773.         } else {

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

  775.         }

  776. 

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

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

  779.         os->packets_written = 0;

  780. 

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

  782.         if (c->single_file) {

  783.             find_index_range(s, full_path, start_pos, &index_length);

  784.         } else {

  785.             ffurl_close(os->out);

  786.             os->out = NULL;

  787.             ret = ff_rename(temp_path, full_path);

  788.             if (ret < 0)

  789.                 break;

  790.         }

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

  792.         av_log(s, AV_LOG_VERBOSE, "Representation %d media segment %d written to: %s\n", i, os->segment_index, full_path);

  793.     }

  794. 

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

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

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

  798.             int j;

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

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

  801.                 remove = os->nb_segments;

  802.             if (remove > 0) {

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

  804.                     char filename[1024];

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

  806.                     unlink(filename);

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

  808.                 }

  809.                 os->nb_segments -= remove;

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

  811.             }

  812.         }

  813.     }

  814. 

  815.     if (ret >= 0)

  816.         ret = write_manifest(s, final);

  817.     return ret;

  818. }

  819. 

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

  821. {

  822.     DASHContext *c = s->priv_data;

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

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

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

  826.     int ret;

  827. 

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

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

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

  831.         s->avoid_negative_ts == AVFMT_AVOID_NEG_TS_MAKE_ZERO) {

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

  833.         pkt->dts  = 0;

  834.     }

  835. 

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

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

  838. 

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

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

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

  842.                       seg_end_duration, AV_TIME_BASE_Q) >= 0) {

  843.         int64_t prev_duration = c->last_duration;

  844. 

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

  846.                                         st->time_base,

  847.                                         AV_TIME_BASE_Q);

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

  849.                                          st->time_base,

  850.                                          AV_TIME_BASE_Q);

  851. 

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

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

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

  855.                 av_log(s, AV_LOG_WARNING,

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

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

  858.             }

  859.         }

  860. 

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

  862.             return ret;

  863.     }

  864. 

  865.     if (!os->packets_written) {

  866.         // If we wrote a previous segment, adjust the start time of the segment

  867.         // to the end of the previous one (which is the same as the mp4 muxer

  868.         // does). This avoids gaps in the timeline.

  869.         if (os->end_dts != AV_NOPTS_VALUE)

  870.             os->start_dts = os->end_dts;

  871.         else

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

  873.     }

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

  875.     os->packets_written++;

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

  877. }

  878. 

  879. static int dash_write_trailer(AVFormatContext *s)

  880. {

  881.     DASHContext *c = s->priv_data;

  882. 

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

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

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

  886.         // guess of the segment duration

  887.         if (!c->last_duration)

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

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

  890.                                             AV_TIME_BASE_Q);

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

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

  893.                                          AV_TIME_BASE_Q);

  894.     }

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

  896. 

  897.     if (c->remove_at_exit) {

  898.         char filename[1024];

  899.         int i;

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

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

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

  903.             unlink(filename);

  904.         }

  905.         unlink(s->filename);

  906.     }

  907. 

  908.     dash_free(s);

  909.     return 0;

  910. }

  911. 

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

  913. #define E AV_OPT_FLAG_ENCODING_PARAM

  914. static const AVOption options[] = {

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

  916.     { "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 },

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

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

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

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

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

  922.     { "single_file_name", "DASH-templated name to be used for baseURL. Implies storing all segments in one file, accessed using byte ranges", OFFSET(single_file_name), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, E },

  923.     { "init_seg_name", "DASH-templated name to used for the initialization segment", OFFSET(init_seg_name), AV_OPT_TYPE_STRING, {.str = "init-stream$RepresentationID$.m4s"},  0, 0, E },

  924.     { "media_seg_name", "DASH-templated name to used for the media segments", OFFSET(media_seg_name), AV_OPT_TYPE_STRING, {.str = "chunk-stream$RepresentationID$-$Number%05d$.m4s"},  0, 0, E },

  925.     { NULL },

  926. };

  927. 

  928. static const AVClass dash_class = {

  929.     .class_name = "dash muxer",

  930.     .item_name  = av_default_item_name,

  931.     .option     = options,

  932.     .version    = LIBAVUTIL_VERSION_INT,

  933. };

  934. 

  935. AVOutputFormat ff_dash_muxer = {

  936.     .name           = "dash",

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

  938.     .priv_data_size = sizeof(DASHContext),

  939.     .audio_codec    = AV_CODEC_ID_AAC,

  940.     .video_codec    = AV_CODEC_ID_H264,

  941.     .flags          = AVFMT_GLOBALHEADER | AVFMT_NOFILE | AVFMT_TS_NEGATIVE,

  942.     .write_header   = dash_write_header,

  943.     .write_packet   = dash_write_packet,

  944.     .write_trailer  = dash_write_trailer,

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

  946.     .priv_class     = &dash_class,

  947. };