lavf/segment: add segment_list_type option, extend format for the segment list file

Add list extended format which specifies in the list file the start and
ending time for each segment. This is required to make it available this
information to external tools, avoiding the need to perform file analysis
in the output segments.

doc/muxers.texi

@@ -450,6 +450,30 @@ listfile is generated.
 @item segment_list_size @var{size}
 Overwrite the listfile once it reaches @var{size} entries. If 0
 the listfile is never overwritten. Default value is 5.
+@item segment_list type @var{type}
+Specify the format for the segment list file.
+
+The following values are recognized:
+@table @option
+@item flat
+Generate a flat list for the created segments, one segment per line.
+
+@item ext
+Generate a list for the created segments, one segment per line,
+each line matching the format:
+@example
+@var{segment_filename},@var{segment_start_time},@var{segment_end_time}
+@end example
+
+@var{segment_filename} is the name of the output file generated by the
+muxer according to the provided pattern, and should not contain the
+"," character for simplifying parsing operations.
+
+@var{segment_start_time} and @var{segment_end_time} specify
+the segment start and end time expressed in seconds.
+@end table
+
+Default value is "flat".
 @item segment_wrap @var{limit}
 Wrap around segment index once it reaches @var{limit}.
 @end table

libavformat/segment.c

@@ -30,6 +30,12 @@
 #include "libavutil/parseutils.h"
 #include "libavutil/mathematics.h"
 
+typedef enum {
+    LIST_TYPE_FLAT = 0,
+    LIST_TYPE_EXT,
+    LIST_TYPE_NB,
+} ListType;
+
 typedef struct {
     const AVClass *class;  /**< Class for private options. */
     int number;
@@ -37,11 +43,13 @@ typedef struct {
     char *format;          ///< format to use for output segment files
     char *list;            ///< filename for the segment list file
     int   list_size;       ///< number of entries for the segment list file
+    ListType list_type;    ///< set the list type
     AVIOContext *list_pb;  ///< list file put-byte context
     float time;            ///< segment duration
     int  wrap;             ///< number after which the index wraps
     int64_t recording_time;
     int has_video;
+    double start_time, end_time;
 } SegmentContext;
 
 static int segment_start(AVFormatContext *s)
@@ -110,7 +118,12 @@ static int segment_end(AVFormatContext *s)
                                   &s->interrupt_callback, NULL)) < 0)
                 goto end;
         }
+
+        if (seg->list_type == LIST_TYPE_FLAT) {
             avio_printf(seg->list_pb, "%s\n", oc->filename);
+        } else if (seg->list_type == LIST_TYPE_EXT) {
+            avio_printf(seg->list_pb, "%s,%f,%f\n", oc->filename, seg->start_time, seg->end_time);
+        }
         avio_flush(seg->list_pb);
     }
 
@@ -216,6 +229,10 @@ static int seg_write_packet(AVFormatContext *s, AVPacket *pkt)
 
         if ((ret = segment_end(s)) < 0 || (ret = segment_start(s)) < 0)
             goto fail;
+        seg->start_time = (double)pkt->pts * av_q2d(st->time_base);
+    } else if (pkt->pts != AV_NOPTS_VALUE) {
+        seg->end_time = FFMAX(seg->end_time,
+                              (double)(pkt->pts + pkt->duration) * av_q2d(st->time_base));
     }
 
     ret = oc->oformat->write_packet(oc, pkt);
@@ -252,6 +269,9 @@ static const AVOption options[] = {
     { "segment_time",      "set segment length in seconds",              OFFSET(time),    AV_OPT_TYPE_FLOAT,  {.dbl = 2},     0, FLT_MAX, E },
     { "segment_list",      "set the segment list filename",              OFFSET(list),    AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,       E },
     { "segment_list_size", "set the maximum number of playlist entries", OFFSET(list_size), AV_OPT_TYPE_INT,  {.dbl = 5},     0, INT_MAX, E },
+    { "segment_list_type", "set the segment list type",                  OFFSET(list_type), AV_OPT_TYPE_INT,  {.dbl = LIST_TYPE_FLAT}, 0, LIST_TYPE_NB-1, E, "list_type" },
+    { "flat", "flat format",     0, AV_OPT_TYPE_CONST, {.dbl=LIST_TYPE_FLAT }, INT_MIN, INT_MAX, 0, "list_type" },
+    { "ext",  "extended format", 0, AV_OPT_TYPE_CONST, {.dbl=LIST_TYPE_EXT  }, INT_MIN, INT_MAX, 0, "list_type" },
     { "segment_wrap",      "set number after which the index wraps",     OFFSET(wrap),    AV_OPT_TYPE_INT,    {.dbl = 0},     0, INT_MAX, E },
     { NULL },
 };

libavformat/version.h

@@ -31,7 +31,7 @@
 
 #define LIBAVFORMAT_VERSION_MAJOR 54
 #define LIBAVFORMAT_VERSION_MINOR 15
-#define LIBAVFORMAT_VERSION_MICRO 100
+#define LIBAVFORMAT_VERSION_MICRO 101
 
 #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
                                                LIBAVFORMAT_VERSION_MINOR, \