avformat/hlsenc: implement program_date_time

Reviewed-by: Steven Liu <lingjiujianke@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

doc/muxers.texi

@@ -522,6 +522,9 @@ behavior on some players when the time between keyframes is inconsistent,
 but may make things worse on others, and can cause some oddities during
 seeking. This flag should be used with the @code{hls_time} option.
 
+@item hls_flags program_date_time
+Generate @code{EXT-X-PROGRAM-DATE-TIME} tags.
+
 @item hls_playlist_type event
 Emit @code{#EXT-X-PLAYLIST-TYPE:EVENT} in the m3u8 header. Forces
 @option{hls_list_size} to 0; the playlist can only be appended to.

libavformat/hlsenc.c

@@ -64,6 +64,7 @@ typedef enum HLSFlags {
     HLS_OMIT_ENDLIST = (1 << 4),
     HLS_SPLIT_BY_TIME = (1 << 5),
     HLS_APPEND_LIST = (1 << 6),
+    HLS_PROGRAM_DATE_TIME = (1 << 7),
 } HLSFlags;
 
 typedef enum {
@@ -128,6 +129,7 @@ typedef struct HLSContext {
 
     char *method;
 
+    double initial_prog_date_time;
 } HLSContext;
 
 static int hls_delete_old_segments(HLSContext *hls) {
@@ -481,6 +483,7 @@ static int hls_window(AVFormatContext *s, int last)
     char *key_uri = NULL;
     char *iv_string = NULL;
     AVDictionary *options = NULL;
+    double prog_date_time = hls->initial_prog_date_time;
 
     if (!use_rename && !warned_non_file++)
         av_log(s, AV_LOG_ERROR, "Cannot use rename on non file protocol, this may lead to races and temporarly partial files\n");
@@ -533,6 +536,19 @@ static int hls_window(AVFormatContext *s, int last)
         if (hls->flags & HLS_SINGLE_FILE)
              avio_printf(out, "#EXT-X-BYTERANGE:%"PRIi64"@%"PRIi64"\n",
                          en->size, en->pos);
+        if (hls->flags & HLS_PROGRAM_DATE_TIME) {
+            time_t tt;
+            int milli;
+            struct tm *tm, tmpbuf;
+            char buf0[128], buf1[128];
+            tt = (int64_t)prog_date_time;
+            milli = av_clip(lrint(1000*(prog_date_time - tt)), 0, 999);
+            tm = localtime_r(&tt, &tmpbuf);
+            strftime(buf0, sizeof(buf0), "%FT%T", tm);
+            strftime(buf1, sizeof(buf1), "%z", tm);
+            avio_printf(out, "#EXT-X-PROGRAM-DATE-TIME:%s.%03d%s\n", buf0, milli, buf1);
+            prog_date_time += en->duration;
+        }
         if (hls->baseurl)
             avio_printf(out, "%s", hls->baseurl);
         avio_printf(out, "%s\n", en->filename);
@@ -710,6 +726,12 @@ static int hls_write_header(AVFormatContext *s)
     hls->recording_time = (hls->init_time ? hls->init_time : hls->time) * AV_TIME_BASE;
     hls->start_pts      = AV_NOPTS_VALUE;
 
+    if (hls->flags & HLS_PROGRAM_DATE_TIME) {
+        time_t now0;
+        time(&now0);
+        hls->initial_prog_date_time = now0;
+    }
+
     if (hls->format_options_str) {
         ret = av_dict_parse_string(&hls->format_options, hls->format_options_str, "=", ":", 0);
         if (ret < 0) {
@@ -1005,6 +1027,7 @@ static const AVOption options[] = {
     {"omit_endlist", "Do not append an endlist when ending stream", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_OMIT_ENDLIST }, 0, UINT_MAX,   E, "flags"},
     {"split_by_time", "split the hls segment by time which user set by hls_time", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_SPLIT_BY_TIME }, 0, UINT_MAX,   E, "flags"},
     {"append_list", "append the new segments into old hls segment list", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_APPEND_LIST }, 0, UINT_MAX,   E, "flags"},
+    {"program_date_time", "add EXT-X-PROGRAM-DATE-TIME", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_PROGRAM_DATE_TIME }, 0, UINT_MAX,   E, "flags"},
     {"use_localtime", "set filename expansion with strftime at segment creation", OFFSET(use_localtime), AV_OPT_TYPE_BOOL, {.i64 = 0 }, 0, 1, E },
     {"use_localtime_mkdir", "create last directory component in strftime-generated filename", OFFSET(use_localtime_mkdir), AV_OPT_TYPE_BOOL, {.i64 = 0 }, 0, 1, E },
     {"hls_playlist_type", "set the HLS playlist type", OFFSET(pl_type), AV_OPT_TYPE_INT, {.i64 = PLAYLIST_TYPE_NONE }, 0, PLAYLIST_TYPE_NB-1, E, "pl_type" },

libavformat/version.h

@@ -33,7 +33,7 @@
 // Also please add any ticket numbers that you believe might be affected here
 #define LIBAVFORMAT_VERSION_MAJOR  57
 #define LIBAVFORMAT_VERSION_MINOR  48
-#define LIBAVFORMAT_VERSION_MICRO 102
+#define LIBAVFORMAT_VERSION_MICRO 103
 
 #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
                                                LIBAVFORMAT_VERSION_MINOR, \