/* * MPEG-DASH ISO BMFF segmenter * Copyright (c) 2014 Martin Storsjo * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "config.h" #if HAVE_UNISTD_H #include #endif #include "libavutil/avassert.h" #include "libavutil/avstring.h" #include "libavutil/intreadwrite.h" #include "libavutil/mathematics.h" #include "libavutil/opt.h" #include "libavutil/rational.h" #include "libavutil/time_internal.h" #include "avc.h" #include "avformat.h" #include "avio_internal.h" #include "internal.h" #include "isom.h" #include "os_support.h" #include "url.h" // See ISO/IEC 23009-1:2014 5.3.9.4.4 typedef enum { DASH_TMPL_ID_UNDEFINED = -1, DASH_TMPL_ID_ESCAPE, DASH_TMPL_ID_REP_ID, DASH_TMPL_ID_NUMBER, DASH_TMPL_ID_BANDWIDTH, DASH_TMPL_ID_TIME, } DASHTmplId; typedef struct Segment { char file[1024]; int64_t start_pos; int range_length, index_length; int64_t time; int duration; int n; } Segment; typedef struct OutputStream { AVFormatContext *ctx; int ctx_inited; uint8_t iobuf[32768]; URLContext *out; int packets_written; char initfile[1024]; int64_t init_start_pos; int init_range_length; int nb_segments, segments_size, segment_index; Segment **segments; int64_t first_pts, start_pts, max_pts; int64_t last_dts; int bit_rate; char bandwidth_str[64]; char codec_str[100]; } OutputStream; typedef struct DASHContext { const AVClass *class; /* Class for private options. */ int window_size; int extra_window_size; int min_seg_duration; int remove_at_exit; int use_template; int use_timeline; int single_file; OutputStream *streams; int has_video, has_audio; int64_t last_duration; int64_t total_duration; char availability_start_time[100]; char dirname[1024]; const char *single_file_name; const char *init_seg_name; const char *media_seg_name; AVRational min_frame_rate, max_frame_rate; int ambiguous_frame_rate; } DASHContext; static int dash_write(void *opaque, uint8_t *buf, int buf_size) { OutputStream *os = opaque; if (os->out) ffurl_write(os->out, buf, buf_size); return buf_size; } // RFC 6381 static void set_codec_str(AVFormatContext *s, AVCodecContext *codec, char *str, int size) { const AVCodecTag *tags[2] = { NULL, NULL }; uint32_t tag; if (codec->codec_type == AVMEDIA_TYPE_VIDEO) tags[0] = ff_codec_movvideo_tags; else if (codec->codec_type == AVMEDIA_TYPE_AUDIO) tags[0] = ff_codec_movaudio_tags; else return; tag = av_codec_get_tag(tags, codec->codec_id); if (!tag) return; if (size < 5) return; AV_WL32(str, tag); str[4] = '\0'; if (!strcmp(str, "mp4a") || !strcmp(str, "mp4v")) { uint32_t oti; tags[0] = ff_mp4_obj_type; oti = av_codec_get_tag(tags, codec->codec_id); if (oti) av_strlcatf(str, size, ".%02x", oti); else return; if (tag == MKTAG('m', 'p', '4', 'a')) { if (codec->extradata_size >= 2) { int aot = codec->extradata[0] >> 3; if (aot == 31) aot = ((AV_RB16(codec->extradata) >> 5) & 0x3f) + 32; av_strlcatf(str, size, ".%d", aot); } } else if (tag == MKTAG('m', 'p', '4', 'v')) { // Unimplemented, should output ProfileLevelIndication as a decimal number av_log(s, AV_LOG_WARNING, "Incomplete RFC 6381 codec string for mp4v\n"); } } else if (!strcmp(str, "avc1")) { uint8_t *tmpbuf = NULL; uint8_t *extradata = codec->extradata; int extradata_size = codec->extradata_size; if (!extradata_size) return; if (extradata[0] != 1) { AVIOContext *pb; if (avio_open_dyn_buf(&pb) < 0) return; if (ff_isom_write_avcc(pb, extradata, extradata_size) < 0) { ffio_free_dyn_buf(&pb); return; } extradata_size = avio_close_dyn_buf(pb, &extradata); tmpbuf = extradata; } if (extradata_size >= 4) av_strlcatf(str, size, ".%02x%02x%02x", extradata[1], extradata[2], extradata[3]); av_free(tmpbuf); } } static void dash_free(AVFormatContext *s) { DASHContext *c = s->priv_data; int i, j; if (!c->streams) return; for (i = 0; i < s->nb_streams; i++) { OutputStream *os = &c->streams[i]; if (os->ctx && os->ctx_inited) av_write_trailer(os->ctx); if (os->ctx && os->ctx->pb) av_free(os->ctx->pb); ffurl_close(os->out); os->out = NULL; if (os->ctx) avformat_free_context(os->ctx); for (j = 0; j < os->nb_segments; j++) av_free(os->segments[j]); av_free(os->segments); } av_freep(&c->streams); } static void output_segment_list(OutputStream *os, AVIOContext *out, DASHContext *c) { int i, start_index = 0, start_number = 1; if (c->window_size) { start_index = FFMAX(os->nb_segments - c->window_size, 0); start_number = FFMAX(os->segment_index - c->window_size, 1); } if (c->use_template) { int timescale = c->use_timeline ? os->ctx->streams[0]->time_base.den : AV_TIME_BASE; avio_printf(out, "\t\t\t\tuse_timeline) avio_printf(out, "duration=\"%"PRId64"\" ", c->last_duration); avio_printf(out, "initialization=\"%s\" media=\"%s\" startNumber=\"%d\">\n", c->init_seg_name, c->media_seg_name, c->use_timeline ? start_number : 1); if (c->use_timeline) { int64_t cur_time = 0; avio_printf(out, "\t\t\t\t\t\n"); for (i = start_index; i < os->nb_segments; ) { Segment *seg = os->segments[i]; int repeat = 0; avio_printf(out, "\t\t\t\t\t\ttime != cur_time) { cur_time = seg->time; avio_printf(out, "t=\"%"PRId64"\" ", seg->time); } avio_printf(out, "d=\"%d\" ", seg->duration); while (i + repeat + 1 < os->nb_segments && os->segments[i + repeat + 1]->duration == seg->duration && os->segments[i + repeat + 1]->time == os->segments[i + repeat]->time + os->segments[i + repeat]->duration) repeat++; if (repeat > 0) avio_printf(out, "r=\"%d\" ", repeat); avio_printf(out, "/>\n"); i += 1 + repeat; cur_time += (1 + repeat) * seg->duration; } avio_printf(out, "\t\t\t\t\t\n"); } avio_printf(out, "\t\t\t\t\n"); } else if (c->single_file) { avio_printf(out, "\t\t\t\t%s\n", os->initfile); avio_printf(out, "\t\t\t\t\n", AV_TIME_BASE, c->last_duration, start_number); avio_printf(out, "\t\t\t\t\t\n", os->init_start_pos, os->init_start_pos + os->init_range_length - 1); for (i = start_index; i < os->nb_segments; i++) { Segment *seg = os->segments[i]; avio_printf(out, "\t\t\t\t\tstart_pos, seg->start_pos + seg->range_length - 1); if (seg->index_length) avio_printf(out, "indexRange=\"%"PRId64"-%"PRId64"\" ", seg->start_pos, seg->start_pos + seg->index_length - 1); avio_printf(out, "/>\n"); } avio_printf(out, "\t\t\t\t\n"); } else { avio_printf(out, "\t\t\t\t\n", AV_TIME_BASE, c->last_duration, start_number); avio_printf(out, "\t\t\t\t\t\n", os->initfile); for (i = start_index; i < os->nb_segments; i++) { Segment *seg = os->segments[i]; avio_printf(out, "\t\t\t\t\t\n", seg->file); } avio_printf(out, "\t\t\t\t\n"); } } static DASHTmplId dash_read_tmpl_id(const char *identifier, char *format_tag, size_t format_tag_size, const char **ptr) { const char *next_ptr; DASHTmplId id_type = DASH_TMPL_ID_UNDEFINED; if (av_strstart(identifier, "$$", &next_ptr)) { id_type = DASH_TMPL_ID_ESCAPE; *ptr = next_ptr; } else if (av_strstart(identifier, "$RepresentationID$", &next_ptr)) { id_type = DASH_TMPL_ID_REP_ID; // default to basic format, as $RepresentationID$ identifiers // are not allowed to have custom format-tags. av_strlcpy(format_tag, "%d", format_tag_size); *ptr = next_ptr; } else { // the following identifiers may have an explicit format_tag if (av_strstart(identifier, "$Number", &next_ptr)) id_type = DASH_TMPL_ID_NUMBER; else if (av_strstart(identifier, "$Bandwidth", &next_ptr)) id_type = DASH_TMPL_ID_BANDWIDTH; else if (av_strstart(identifier, "$Time", &next_ptr)) id_type = DASH_TMPL_ID_TIME; else id_type = DASH_TMPL_ID_UNDEFINED; // next parse the dash format-tag and generate a c-string format tag // (next_ptr now points at the first '%' at the beginning of the format-tag) if (id_type != DASH_TMPL_ID_UNDEFINED) { const char *number_format = (id_type == DASH_TMPL_ID_TIME) ? PRId64 : "d"; if (next_ptr[0] == '$') { // no dash format-tag snprintf(format_tag, format_tag_size, "%%%s", number_format); *ptr = &next_ptr[1]; } else { const char *width_ptr; // only tolerate single-digit width-field (i.e. up to 9-digit width) if (av_strstart(next_ptr, "%0", &width_ptr) && av_isdigit(width_ptr[0]) && av_strstart(&width_ptr[1], "d$", &next_ptr)) { // yes, we're using a format tag to build format_tag. snprintf(format_tag, format_tag_size, "%s%c%s", "%0", width_ptr[0], number_format); *ptr = next_ptr; } else { av_log(NULL, AV_LOG_WARNING, "Failed to parse format-tag beginning with %s. Expected either a " "closing '$' character or a format-string like '%%0[width]d', " "where width must be a single digit\n", next_ptr); id_type = DASH_TMPL_ID_UNDEFINED; } } } } return id_type; } static void dash_fill_tmpl_params(char *dst, size_t buffer_size, const char *template, int rep_id, int number, int bit_rate, int64_t time) { int dst_pos = 0; const char *t_cur = template; while (dst_pos < buffer_size - 1 && *t_cur) { char format_tag[7]; // May be "%d", "%0Xd", or "%0Xlld" (for $Time$), where X is in [0-9] int n = 0; DASHTmplId id_type; const char *t_next = strchr(t_cur, '$'); // copy over everything up to the first '$' character if (t_next) { int num_copy_bytes = FFMIN(t_next - t_cur, buffer_size - dst_pos - 1); av_strlcpy(&dst[dst_pos], t_cur, num_copy_bytes + 1); // advance dst_pos += num_copy_bytes; t_cur = t_next; } else { // no more DASH identifiers to substitute - just copy the rest over and break av_strlcpy(&dst[dst_pos], t_cur, buffer_size - dst_pos); break; } if (dst_pos >= buffer_size - 1 || !*t_cur) break; // t_cur is now pointing to a '$' character id_type = dash_read_tmpl_id(t_cur, format_tag, sizeof(format_tag), &t_next); switch (id_type) { case DASH_TMPL_ID_ESCAPE: av_strlcpy(&dst[dst_pos], "$", 2); n = 1; break; case DASH_TMPL_ID_REP_ID: n = snprintf(&dst[dst_pos], buffer_size - dst_pos, format_tag, rep_id); break; case DASH_TMPL_ID_NUMBER: n = snprintf(&dst[dst_pos], buffer_size - dst_pos, format_tag, number); break; case DASH_TMPL_ID_BANDWIDTH: n = snprintf(&dst[dst_pos], buffer_size - dst_pos, format_tag, bit_rate); break; case DASH_TMPL_ID_TIME: n = snprintf(&dst[dst_pos], buffer_size - dst_pos, format_tag, time); break; case DASH_TMPL_ID_UNDEFINED: // copy over one byte and advance av_strlcpy(&dst[dst_pos], t_cur, 2); n = 1; t_next = &t_cur[1]; break; } // t_next points just past the processed identifier // n is the number of bytes that were attempted to be written to dst // (may have failed to write all because buffer_size). // advance dst_pos += FFMIN(n, buffer_size - dst_pos - 1); t_cur = t_next; } } static char *xmlescape(const char *str) { int outlen = strlen(str)*3/2 + 6; char *out = av_realloc(NULL, outlen + 1); int pos = 0; if (!out) return NULL; for (; *str; str++) { if (pos + 6 > outlen) { char *tmp; outlen = 2 * outlen + 6; tmp = av_realloc(out, outlen + 1); if (!tmp) { av_free(out); return NULL; } out = tmp; } if (*str == '&') { memcpy(&out[pos], "&", 5); pos += 5; } else if (*str == '<') { memcpy(&out[pos], "<", 4); pos += 4; } else if (*str == '>') { memcpy(&out[pos], ">", 4); pos += 4; } else if (*str == '\'') { memcpy(&out[pos], "'", 6); pos += 6; } else if (*str == '\"') { memcpy(&out[pos], """, 6); pos += 6; } else { out[pos++] = *str; } } out[pos] = '\0'; return out; } static void write_time(AVIOContext *out, int64_t time) { int seconds = time / AV_TIME_BASE; int fractions = time % AV_TIME_BASE; int minutes = seconds / 60; int hours = minutes / 60; seconds %= 60; minutes %= 60; avio_printf(out, "PT"); if (hours) avio_printf(out, "%dH", hours); if (hours || minutes) avio_printf(out, "%dM", minutes); avio_printf(out, "%d.%dS", seconds, fractions / (AV_TIME_BASE / 10)); } static void format_date_now(char *buf, int size) { time_t t = time(NULL); struct tm *ptm, tmbuf; ptm = gmtime_r(&t, &tmbuf); if (ptm) { if (!strftime(buf, size, "%Y-%m-%dT%H:%M:%S", ptm)) buf[0] = '\0'; } } static int write_manifest(AVFormatContext *s, int final) { DASHContext *c = s->priv_data; AVIOContext *out; char temp_filename[1024]; int ret, i; AVDictionaryEntry *title = av_dict_get(s->metadata, "title", NULL, 0); snprintf(temp_filename, sizeof(temp_filename), "%s.tmp", s->filename); ret = avio_open2(&out, temp_filename, AVIO_FLAG_WRITE, &s->interrupt_callback, NULL); if (ret < 0) { av_log(s, AV_LOG_ERROR, "Unable to open %s for writing\n", temp_filename); return ret; } avio_printf(out, "\n"); avio_printf(out, "total_duration); avio_printf(out, "\"\n"); } else { int64_t update_period = c->last_duration / AV_TIME_BASE; char now_str[100]; if (c->use_template && !c->use_timeline) update_period = 500; avio_printf(out, "\tminimumUpdatePeriod=\"PT%"PRId64"S\"\n", update_period); avio_printf(out, "\tsuggestedPresentationDelay=\"PT%"PRId64"S\"\n", c->last_duration / AV_TIME_BASE); if (!c->availability_start_time[0] && s->nb_streams > 0 && c->streams[0].nb_segments > 0) { format_date_now(c->availability_start_time, sizeof(c->availability_start_time)); } if (c->availability_start_time[0]) avio_printf(out, "\tavailabilityStartTime=\"%s\"\n", c->availability_start_time); format_date_now(now_str, sizeof(now_str)); if (now_str[0]) avio_printf(out, "\tpublishTime=\"%s\"\n", now_str); if (c->window_size && c->use_template) { avio_printf(out, "\ttimeShiftBufferDepth=\""); write_time(out, c->last_duration * c->window_size); avio_printf(out, "\"\n"); } } avio_printf(out, "\tminBufferTime=\""); write_time(out, c->last_duration); avio_printf(out, "\">\n"); avio_printf(out, "\t\n"); if (title) { char *escaped = xmlescape(title->value); avio_printf(out, "\t\t%s\n", escaped); av_free(escaped); } avio_printf(out, "\t\n"); if (c->window_size && s->nb_streams > 0 && c->streams[0].nb_segments > 0 && !c->use_template) { OutputStream *os = &c->streams[0]; int start_index = FFMAX(os->nb_segments - c->window_size, 0); int64_t start_time = av_rescale_q(os->segments[start_index]->time, s->streams[0]->time_base, AV_TIME_BASE_Q); avio_printf(out, "\t\n"); } else { avio_printf(out, "\t\n"); } if (c->has_video) { avio_printf(out, "\t\tmax_frame_rate.num && !c->ambiguous_frame_rate) avio_printf(out, " %s=\"%d/%d\"", (av_cmp_q(c->min_frame_rate, c->max_frame_rate) < 0) ? "maxFrameRate" : "frameRate", c->max_frame_rate.num, c->max_frame_rate.den); avio_printf(out, ">\n"); for (i = 0; i < s->nb_streams; i++) { AVStream *st = s->streams[i]; OutputStream *os = &c->streams[i]; if (st->codec->codec_type != AVMEDIA_TYPE_VIDEO) continue; avio_printf(out, "\t\t\tcodec_str, os->bandwidth_str, st->codec->width, st->codec->height); if (st->avg_frame_rate.num) avio_printf(out, " frameRate=\"%d/%d\"", st->avg_frame_rate.num, st->avg_frame_rate.den); avio_printf(out, ">\n"); output_segment_list(&c->streams[i], out, c); avio_printf(out, "\t\t\t\n"); } avio_printf(out, "\t\t\n"); } if (c->has_audio) { avio_printf(out, "\t\t\n"); for (i = 0; i < s->nb_streams; i++) { AVStream *st = s->streams[i]; OutputStream *os = &c->streams[i]; if (st->codec->codec_type != AVMEDIA_TYPE_AUDIO) continue; avio_printf(out, "\t\t\t\n", i, os->codec_str, os->bandwidth_str, st->codec->sample_rate); avio_printf(out, "\t\t\t\t\n", st->codec->channels); output_segment_list(&c->streams[i], out, c); avio_printf(out, "\t\t\t\n"); } avio_printf(out, "\t\t\n"); } avio_printf(out, "\t\n"); avio_printf(out, "\n"); avio_flush(out); avio_close(out); return ff_rename(temp_filename, s->filename, s); } static int dash_write_header(AVFormatContext *s) { DASHContext *c = s->priv_data; int ret = 0, i; AVOutputFormat *oformat; char *ptr; char basename[1024]; if (c->single_file_name) c->single_file = 1; if (c->single_file) c->use_template = 0; c->ambiguous_frame_rate = 0; av_strlcpy(c->dirname, s->filename, sizeof(c->dirname)); ptr = strrchr(c->dirname, '/'); if (ptr) { av_strlcpy(basename, &ptr[1], sizeof(basename)); ptr[1] = '\0'; } else { c->dirname[0] = '\0'; av_strlcpy(basename, s->filename, sizeof(basename)); } ptr = strrchr(basename, '.'); if (ptr) *ptr = '\0'; oformat = av_guess_format("mp4", NULL, NULL); if (!oformat) { ret = AVERROR_MUXER_NOT_FOUND; goto fail; } c->streams = av_mallocz(sizeof(*c->streams) * s->nb_streams); if (!c->streams) { ret = AVERROR(ENOMEM); goto fail; } for (i = 0; i < s->nb_streams; i++) { OutputStream *os = &c->streams[i]; AVFormatContext *ctx; AVStream *st; AVDictionary *opts = NULL; char filename[1024]; os->bit_rate = s->streams[i]->codec->bit_rate ? s->streams[i]->codec->bit_rate : s->streams[i]->codec->rc_max_rate; if (os->bit_rate) { snprintf(os->bandwidth_str, sizeof(os->bandwidth_str), " bandwidth=\"%d\"", os->bit_rate); } else { int level = s->strict_std_compliance >= FF_COMPLIANCE_STRICT ? AV_LOG_ERROR : AV_LOG_WARNING; av_log(s, level, "No bit rate set for stream %d\n", i); if (s->strict_std_compliance >= FF_COMPLIANCE_STRICT) { ret = AVERROR(EINVAL); goto fail; } } ctx = avformat_alloc_context(); if (!ctx) { ret = AVERROR(ENOMEM); goto fail; } os->ctx = ctx; ctx->oformat = oformat; ctx->interrupt_callback = s->interrupt_callback; if (!(st = avformat_new_stream(ctx, NULL))) { ret = AVERROR(ENOMEM); goto fail; } avcodec_copy_context(st->codec, s->streams[i]->codec); st->sample_aspect_ratio = s->streams[i]->sample_aspect_ratio; st->time_base = s->streams[i]->time_base; ctx->avoid_negative_ts = s->avoid_negative_ts; ctx->pb = avio_alloc_context(os->iobuf, sizeof(os->iobuf), AVIO_FLAG_WRITE, os, NULL, dash_write, NULL); if (!ctx->pb) { ret = AVERROR(ENOMEM); goto fail; } if (c->single_file) { if (c->single_file_name) dash_fill_tmpl_params(os->initfile, sizeof(os->initfile), c->single_file_name, i, 0, os->bit_rate, 0); else snprintf(os->initfile, sizeof(os->initfile), "%s-stream%d.m4s", basename, i); } else { dash_fill_tmpl_params(os->initfile, sizeof(os->initfile), c->init_seg_name, i, 0, os->bit_rate, 0); } snprintf(filename, sizeof(filename), "%s%s", c->dirname, os->initfile); ret = ffurl_open(&os->out, filename, AVIO_FLAG_WRITE, &s->interrupt_callback, NULL); if (ret < 0) goto fail; os->init_start_pos = 0; av_dict_set(&opts, "movflags", "frag_custom+dash+delay_moov", 0); if ((ret = avformat_write_header(ctx, &opts)) < 0) { goto fail; } os->ctx_inited = 1; avio_flush(ctx->pb); av_dict_free(&opts); av_log(s, AV_LOG_VERBOSE, "Representation %d init segment will be written to: %s\n", i, filename); s->streams[i]->time_base = st->time_base; // If the muxer wants to shift timestamps, request to have them shifted // already before being handed to this muxer, so we don't have mismatches // between the MPD and the actual segments. s->avoid_negative_ts = ctx->avoid_negative_ts; if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) { AVRational avg_frame_rate = s->streams[i]->avg_frame_rate; if (avg_frame_rate.num > 0) { if (av_cmp_q(avg_frame_rate, c->min_frame_rate) < 0) c->min_frame_rate = avg_frame_rate; if (av_cmp_q(c->max_frame_rate, avg_frame_rate) < 0) c->max_frame_rate = avg_frame_rate; } else { c->ambiguous_frame_rate = 1; } c->has_video = 1; } else if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO) { c->has_audio = 1; } set_codec_str(s, st->codec, os->codec_str, sizeof(os->codec_str)); os->first_pts = AV_NOPTS_VALUE; os->max_pts = AV_NOPTS_VALUE; os->last_dts = AV_NOPTS_VALUE; os->segment_index = 1; } if (!c->has_video && c->min_seg_duration <= 0) { av_log(s, AV_LOG_WARNING, "no video stream and no min seg duration set\n"); ret = AVERROR(EINVAL); } ret = write_manifest(s, 0); if (!ret) av_log(s, AV_LOG_VERBOSE, "Manifest written to: %s\n", s->filename); fail: if (ret) dash_free(s); return ret; } static int add_segment(OutputStream *os, const char *file, int64_t time, int duration, int64_t start_pos, int64_t range_length, int64_t index_length) { int err; Segment *seg; if (os->nb_segments >= os->segments_size) { os->segments_size = (os->segments_size + 1) * 2; if ((err = av_reallocp(&os->segments, sizeof(*os->segments) * os->segments_size)) < 0) { os->segments_size = 0; os->nb_segments = 0; return err; } } seg = av_mallocz(sizeof(*seg)); if (!seg) return AVERROR(ENOMEM); av_strlcpy(seg->file, file, sizeof(seg->file)); seg->time = time; seg->duration = duration; if (seg->time < 0) { // If pts<0, it is expected to be cut away with an edit list seg->duration += seg->time; seg->time = 0; } seg->start_pos = start_pos; seg->range_length = range_length; seg->index_length = index_length; os->segments[os->nb_segments++] = seg; os->segment_index++; return 0; } static void write_styp(AVIOContext *pb) { avio_wb32(pb, 24); ffio_wfourcc(pb, "styp"); ffio_wfourcc(pb, "msdh"); avio_wb32(pb, 0); /* minor */ ffio_wfourcc(pb, "msdh"); ffio_wfourcc(pb, "msix"); } static void find_index_range(AVFormatContext *s, const char *full_path, int64_t pos, int *index_length) { uint8_t buf[8]; URLContext *fd; int ret; ret = ffurl_open(&fd, full_path, AVIO_FLAG_READ, &s->interrupt_callback, NULL); if (ret < 0) return; if (ffurl_seek(fd, pos, SEEK_SET) != pos) { ffurl_close(fd); return; } ret = ffurl_read(fd, buf, 8); ffurl_close(fd); if (ret < 8) return; if (AV_RL32(&buf[4]) != MKTAG('s', 'i', 'd', 'x')) return; *index_length = AV_RB32(&buf[0]); } static int update_stream_extradata(AVFormatContext *s, OutputStream *os, AVCodecContext *codec) { uint8_t *extradata; if (os->ctx->streams[0]->codec->extradata_size || !codec->extradata_size) return 0; extradata = av_malloc(codec->extradata_size); if (!extradata) return AVERROR(ENOMEM); memcpy(extradata, codec->extradata, codec->extradata_size); os->ctx->streams[0]->codec->extradata = extradata; os->ctx->streams[0]->codec->extradata_size = codec->extradata_size; set_codec_str(s, codec, os->codec_str, sizeof(os->codec_str)); return 0; } static int dash_flush(AVFormatContext *s, int final, int stream) { DASHContext *c = s->priv_data; int i, ret = 0; int cur_flush_segment_index = 0; if (stream >= 0) cur_flush_segment_index = c->streams[stream].segment_index; for (i = 0; i < s->nb_streams; i++) { OutputStream *os = &c->streams[i]; char filename[1024] = "", full_path[1024], temp_path[1024]; int64_t start_pos; int range_length, index_length = 0; if (!os->packets_written) continue; // Flush the single stream that got a keyframe right now. // Flush all audio streams as well, in sync with video keyframes, // but not the other video streams. if (stream >= 0 && i != stream) { if (s->streams[i]->codec->codec_type != AVMEDIA_TYPE_AUDIO) continue; // Make sure we don't flush audio streams multiple times, when // all video streams are flushed one at a time. if (c->has_video && os->segment_index > cur_flush_segment_index) continue; } if (!os->init_range_length) { av_write_frame(os->ctx, NULL); os->init_range_length = avio_tell(os->ctx->pb); if (!c->single_file) { ffurl_close(os->out); os->out = NULL; } } start_pos = avio_tell(os->ctx->pb); if (!c->single_file) { dash_fill_tmpl_params(filename, sizeof(filename), c->media_seg_name, i, os->segment_index, os->bit_rate, os->start_pts); snprintf(full_path, sizeof(full_path), "%s%s", c->dirname, filename); snprintf(temp_path, sizeof(temp_path), "%s.tmp", full_path); ret = ffurl_open(&os->out, temp_path, AVIO_FLAG_WRITE, &s->interrupt_callback, NULL); if (ret < 0) break; write_styp(os->ctx->pb); } else { snprintf(full_path, sizeof(full_path), "%s%s", c->dirname, os->initfile); } av_write_frame(os->ctx, NULL); avio_flush(os->ctx->pb); os->packets_written = 0; range_length = avio_tell(os->ctx->pb) - start_pos; if (c->single_file) { find_index_range(s, full_path, start_pos, &index_length); } else { ffurl_close(os->out); os->out = NULL; ret = ff_rename(temp_path, full_path, s); if (ret < 0) break; } add_segment(os, filename, os->start_pts, os->max_pts - os->start_pts, start_pos, range_length, index_length); av_log(s, AV_LOG_VERBOSE, "Representation %d media segment %d written to: %s\n", i, os->segment_index, full_path); } if (c->window_size || (final && c->remove_at_exit)) { for (i = 0; i < s->nb_streams; i++) { OutputStream *os = &c->streams[i]; int j; int remove = os->nb_segments - c->window_size - c->extra_window_size; if (final && c->remove_at_exit) remove = os->nb_segments; if (remove > 0) { for (j = 0; j < remove; j++) { char filename[1024]; snprintf(filename, sizeof(filename), "%s%s", c->dirname, os->segments[j]->file); unlink(filename); av_free(os->segments[j]); } os->nb_segments -= remove; memmove(os->segments, os->segments + remove, os->nb_segments * sizeof(*os->segments)); } } } if (ret >= 0) ret = write_manifest(s, final); return ret; } static int dash_write_packet(AVFormatContext *s, AVPacket *pkt) { DASHContext *c = s->priv_data; AVStream *st = s->streams[pkt->stream_index]; OutputStream *os = &c->streams[pkt->stream_index]; int64_t seg_end_duration = (os->segment_index) * (int64_t) c->min_seg_duration; int ret; ret = update_stream_extradata(s, os, st->codec); if (ret < 0) return ret; // Fill in a heuristic guess of the packet duration, if none is available. // The mp4 muxer will do something similar (for the last packet in a fragment) // if nothing is set (setting it for the other packets doesn't hurt). // By setting a nonzero duration here, we can be sure that the mp4 muxer won't // invoke its heuristic (this doesn't have to be identical to that algorithm), // so that we know the exact timestamps of fragments. if (!pkt->duration && os->last_dts != AV_NOPTS_VALUE) pkt->duration = pkt->dts - os->last_dts; os->last_dts = pkt->dts; // If forcing the stream to start at 0, the mp4 muxer will set the start // timestamps to 0. Do the same here, to avoid mismatches in duration/timestamps. if (os->first_pts == AV_NOPTS_VALUE && s->avoid_negative_ts == AVFMT_AVOID_NEG_TS_MAKE_ZERO) { pkt->pts -= pkt->dts; pkt->dts = 0; } if (os->first_pts == AV_NOPTS_VALUE) os->first_pts = pkt->pts; if ((!c->has_video || st->codec->codec_type == AVMEDIA_TYPE_VIDEO) && pkt->flags & AV_PKT_FLAG_KEY && os->packets_written && av_compare_ts(pkt->pts - os->first_pts, st->time_base, seg_end_duration, AV_TIME_BASE_Q) >= 0) { int64_t prev_duration = c->last_duration; c->last_duration = av_rescale_q(pkt->pts - os->start_pts, st->time_base, AV_TIME_BASE_Q); c->total_duration = av_rescale_q(pkt->pts - os->first_pts, st->time_base, AV_TIME_BASE_Q); if ((!c->use_timeline || !c->use_template) && prev_duration) { if (c->last_duration < prev_duration*9/10 || c->last_duration > prev_duration*11/10) { av_log(s, AV_LOG_WARNING, "Segment durations differ too much, enable use_timeline " "and use_template, or keep a stricter keyframe interval\n"); } } if ((ret = dash_flush(s, 0, pkt->stream_index)) < 0) return ret; } if (!os->packets_written) { // If we wrote a previous segment, adjust the start time of the segment // to the end of the previous one (which is the same as the mp4 muxer // does). This avoids gaps in the timeline. if (os->max_pts != AV_NOPTS_VALUE) os->start_pts = os->max_pts; else os->start_pts = pkt->pts; } if (os->max_pts == AV_NOPTS_VALUE) os->max_pts = pkt->pts + pkt->duration; else os->max_pts = FFMAX(os->max_pts, pkt->pts + pkt->duration); os->packets_written++; return ff_write_chained(os->ctx, 0, pkt, s, 0); } static int dash_write_trailer(AVFormatContext *s) { DASHContext *c = s->priv_data; if (s->nb_streams > 0) { OutputStream *os = &c->streams[0]; // If no segments have been written so far, try to do a crude // guess of the segment duration if (!c->last_duration) c->last_duration = av_rescale_q(os->max_pts - os->start_pts, s->streams[0]->time_base, AV_TIME_BASE_Q); c->total_duration = av_rescale_q(os->max_pts - os->first_pts, s->streams[0]->time_base, AV_TIME_BASE_Q); } dash_flush(s, 1, -1); if (c->remove_at_exit) { char filename[1024]; int i; for (i = 0; i < s->nb_streams; i++) { OutputStream *os = &c->streams[i]; snprintf(filename, sizeof(filename), "%s%s", c->dirname, os->initfile); unlink(filename); } unlink(s->filename); } dash_free(s); return 0; } #define OFFSET(x) offsetof(DASHContext, x) #define E AV_OPT_FLAG_ENCODING_PARAM static const AVOption options[] = { { "window_size", "number of segments kept in the manifest", OFFSET(window_size), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, E }, { "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 }, { "min_seg_duration", "minimum segment duration (in microseconds)", OFFSET(min_seg_duration), AV_OPT_TYPE_INT64, { .i64 = 5000000 }, 0, INT_MAX, E }, { "remove_at_exit", "remove all segments when finished", OFFSET(remove_at_exit), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, E }, { "use_template", "Use SegmentTemplate instead of SegmentList", OFFSET(use_template), AV_OPT_TYPE_BOOL, { .i64 = 1 }, 0, 1, E }, { "use_timeline", "Use SegmentTimeline in SegmentTemplate", OFFSET(use_timeline), AV_OPT_TYPE_BOOL, { .i64 = 1 }, 0, 1, E }, { "single_file", "Store all segments in one file, accessed using byte ranges", OFFSET(single_file), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, E }, { "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 }, { "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 }, { "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 }, { NULL }, }; static const AVClass dash_class = { .class_name = "dash muxer", .item_name = av_default_item_name, .option = options, .version = LIBAVUTIL_VERSION_INT, }; AVOutputFormat ff_dash_muxer = { .name = "dash", .long_name = NULL_IF_CONFIG_SMALL("DASH Muxer"), .priv_data_size = sizeof(DASHContext), .audio_codec = AV_CODEC_ID_AAC, .video_codec = AV_CODEC_ID_H264, .flags = AVFMT_GLOBALHEADER | AVFMT_NOFILE | AVFMT_TS_NEGATIVE, .write_header = dash_write_header, .write_packet = dash_write_packet, .write_trailer = dash_write_trailer, .codec_tag = (const AVCodecTag* const []){ ff_mp4_obj_type, 0 }, .priv_class = &dash_class, };