avformat/hlsenc: strftime identifiers and segment index

 in filenames

Putting date/time values into segment filenames is very usefull.
But to produce non-conflicting segment filenames with -use_localtime
option with date/time
values in hls_segment_filename option, sometimes is not enough.
Like in cases when multiple segments produced in the same second.
But hlsenc currently does not make possible to use segment index (%d) at
the

same time whe use_localtime is in effect, due to identifier conflict.
This patch makes possible to use strftime identifiers and still put
segment index (%d) at same time in segment filenames by introducing
second_level_segment_index flag. When -use_localtime is active,
identifier %d is for month day index, so %%d is the segment index
placeholder. This enhanced behaviour only exists when new
second_level_segment_index flag is specified.
For instance putting 'segment_%Y%m%d%H%M%S_%%05d.ts' value into
-hls_segment_filename option and specifing -hls_flags
second_level_segment_index and -use_localtime 1, may produce segment
filename as 'segment_20161230235758_00002.ts'

An example:

ffmpeg -loglevel info -y -f lavfi -i color=c=red:size=640x480:r=25 -f
lavfi -i anullsrc=r=44100:cl=stereo -c:v mpeg2video -g 25 -acodec aac
-cutoff 20000 -ac 2 -ar 44100 -ab 192k -f hls -hls_time 3 -hls_list_size
5 -hls_flags delete_segments+second_level_segment_index -use_localtime 1
-hls_segment_filename "segment_%Y%m%d%H%M%S_%%05d.ts" stream.m3u8

will produce segments filenames:

....
segment_20161227005902_00013.ts
segment_20161227005902_00014.ts
segment_20161227005902_00015.ts
segment_20161227005903_00016.ts
segment_20161227005903_00017.ts
segment_20161227005903_00018.ts
segment_20161227005903_00019.ts
segment_20161227005903_00020.ts
....

Signed-off-by: Bela Bodecs <bodecsb@vivanet.hu>

1 files changed, 10 insertions, 1 deletions

diff --git a/doc/muxers.texi b/doc/muxers.texi
index 075b8d3117..3520120471 100644
--- a/doc/muxers.texi
+++ b/doc/muxers.texi
@@ -443,12 +443,18 @@ This example will produce the playlist, @file{out.m3u8}, and segment files:
 
 @item use_localtime
 Use strftime on @var{filename} to expand the segment filename with localtime.
-The segment number (%d) is not available in this mode.
+The segment number is also available in this mode, but to use it, you need to specify second_level_segment_index
+hls_flag and %%d will be the specifier.
 @example
 ffmpeg -i in.nut -use_localtime 1 -hls_segment_filename 'file-%Y%m%d-%s.ts' out.m3u8
 @end example
 This example will produce the playlist, @file{out.m3u8}, and segment files:
 @file{file-20160215-1455569023.ts}, @file{file-20160215-1455569024.ts}, etc.
+@example
+ffmpeg -i in.nut -use_localtime 1 -hls_flags second_level_segment_index -hls_segment_filename 'file-%Y%m%d-%%04d.ts' out.m3u8
+@end example
+This example will produce the playlist, @file{out.m3u8}, and segment files:
+@file{file-20160215-0001.ts}, @file{file-20160215-0002.ts}, etc.
 
 @item use_localtime_mkdir
 Used together with -use_localtime, it will create up to one subdirectory which
@@ -556,6 +562,9 @@ 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_flags second_level_segment_index
+Makes it possible to use segment indexes as %%d besides date/time values when use_localtime is on.
+
 @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.