[FFmpeg-cvslog] dashenc: Add options to make segment names configurable
Bryan Huh
git at videolan.org
Fri Nov 28 13:04:48 CET 2014
ffmpeg | branch: master | Bryan Huh <bryan at box.com> | Thu Nov 27 09:46:02 2014 +0000| [a9d8d35e4833fc4dfbf557ce73c84e9ca6224427] | committer: Martin Storsjö
dashenc: Add options to make segment names configurable
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 <martin at martin.st>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=a9d8d35e4833fc4dfbf557ce73c84e9ca6224427
---
libavformat/dashenc.c | 154 ++++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 146 insertions(+), 8 deletions(-)
diff --git a/libavformat/dashenc.c b/libavformat/dashenc.c
index 0654661..9a8169e 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\t<SegmentTemplate timescale=\"%d\" ", timescale);
if (!c->use_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<SegmentTimeline>\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 },
};
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