From a9d8d35e4833fc4dfbf557ce73c84e9ca6224427 Mon Sep 17 00:00:00 2001 From: Bryan Huh Date: Thu, 27 Nov 2014 09:46:02 +0000 Subject: dashenc: Add options to make segment names configurable MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This allows one to specify templated segment names for init-segments, media-segments, and for the base-url in the case of single-file. Signed-off-by: Martin Storsjö --- libavformat/dashenc.c | 154 +++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 146 insertions(+), 8 deletions(-) (limited to 'libavformat/dashenc.c') diff --git a/libavformat/dashenc.c b/libavformat/dashenc.c index 065466169e..9a8169e167 100644 --- a/libavformat/dashenc.c +++ b/libavformat/dashenc.c @@ -38,6 +38,16 @@ #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; @@ -59,6 +69,7 @@ typedef struct OutputStream { int nb_segments, segments_size, segment_index; Segment **segments; int64_t first_dts, start_dts, end_dts; + int bit_rate; char bandwidth_str[64]; char codec_str[100]; @@ -79,6 +90,9 @@ typedef struct DASHContext { int 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; } DASHContext; static int dash_write(void *opaque, uint8_t *buf, int buf_size) @@ -192,7 +206,7 @@ static void output_segment_list(OutputStream *os, AVIOContext *out, DASHContext avio_printf(out, "\t\t\t\tuse_timeline) avio_printf(out, "duration=\"%d\" ", c->last_duration); - avio_printf(out, "initialization=\"init-stream$RepresentationID$.m4s\" media=\"chunk-stream$RepresentationID$-$Number%%05d$.m4s\" startNumber=\"%d\">\n", c->use_timeline ? start_number : 1); + 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) { avio_printf(out, "\t\t\t\t\t\n"); for (i = start_index; i < os->nb_segments; ) { @@ -235,6 +249,120 @@ static void output_segment_list(OutputStream *os, AVIOContext *out, DASHContext } } +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, "$Time", &next_ptr)) + id_type = DASH_TMPL_ID_TIME; + else + id_type = DASH_TMPL_ID_UNDEFINED; + + // next parse the dash format-tag and generate a c-string format tag + // (next_ptr now points at the first '%' at the beginning of the format-tag) + if (id_type != DASH_TMPL_ID_UNDEFINED) { + const char *number_format = DASH_TMPL_ID_TIME ? "lld" : "d"; + if (next_ptr[0] == '$') { // 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) { + int format_tag_size = 7; + char format_tag[format_tag_size]; // 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 '$' character + id_type = dash_read_tmpl_id(t_cur, format_tag, format_tag_size, &t_next); + switch (id_type) { + case DASH_TMPL_ID_ESCAPE: + av_strlcpy(&dst[dst_pos], "$", 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); @@ -403,6 +531,8 @@ static int dash_write_header(AVFormatContext *s) char *ptr; char basename[1024]; + if (c->single_file_name) + c->single_file = 1; if (c->single_file) c->use_template = 0; @@ -439,9 +569,10 @@ static int dash_write_header(AVFormatContext *s) AVDictionary *opts = NULL; char filename[1024]; - if (s->streams[i]->codec->bit_rate) { + os->bit_rate = s->streams[i]->codec->bit_rate; + if (os->bit_rate) { snprintf(os->bandwidth_str, sizeof(os->bandwidth_str), - " bandwidth=\"%d\"", s->streams[i]->codec->bit_rate); + " bandwidth=\"%d\"", os->bit_rate); } else { int level = s->strict_std_compliance >= FF_COMPLIANCE_STRICT ? AV_LOG_ERROR : AV_LOG_WARNING; @@ -476,10 +607,14 @@ static int dash_write_header(AVFormatContext *s) goto fail; } - if (c->single_file) - snprintf(os->initfile, sizeof(os->initfile), "%s-stream%d.m4s", basename, i); - else - snprintf(os->initfile, sizeof(os->initfile), "init-stream%d.m4s", i); + 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) @@ -624,7 +759,7 @@ static int dash_flush(AVFormatContext *s, int final, int stream) } if (!c->single_file) { - snprintf(filename, sizeof(filename), "chunk-stream%d-%05d.m4s", i, os->segment_index); + dash_fill_tmpl_params(filename, sizeof(filename), c->media_seg_name, i, os->segment_index, os->bit_rate, os->start_dts); 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); @@ -769,6 +904,9 @@ static const AVOption options[] = { { "use_template", "Use SegmentTemplate instead of SegmentList", OFFSET(use_template), AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 1, E }, { "use_timeline", "Use SegmentTimeline in SegmentTemplate", OFFSET(use_timeline), AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 1, E }, { "single_file", "Store all segments in one file, accessed using byte ranges", OFFSET(single_file), AV_OPT_TYPE_INT, { .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 }, }; -- cgit v1.2.3