[FFmpeg-devel] [PATCH] Add init_program_date_time so start time can be specified

[David Johansen]

On Tue, Oct 17, 2023 at 7:09 PM <epirat07 at gmail.com> wrote:

>
>
> On 17 Oct 2023, at 17:51, Dave Johansen wrote:
>
> > ---
> >  doc/muxers.texi      | 3 +++
> >  libavformat/hlsenc.c | 7 ++++++-
> >  2 files changed, 9 insertions(+), 1 deletion(-)
> >
> > diff --git a/doc/muxers.texi b/doc/muxers.texi
> > index f6071484ff..87c19a5cb9 100644
> > --- a/doc/muxers.texi
> > +++ b/doc/muxers.texi
> > @@ -1086,6 +1086,9 @@ seeking. This flag should be used with the
> @code{hls_time} option.
> >  @item program_date_time
> >  Generate @code{EXT-X-PROGRAM-DATE-TIME} tags.
> >
> > + at item init_program_date_time
> > +Time to start program date time at.
> > +
> >  @item second_level_segment_index
> >  Makes it possible to use segment indexes as %%d in hls_segment_filename
> expression
> >  besides date/time values when strftime is on.
> > diff --git a/libavformat/hlsenc.c b/libavformat/hlsenc.c
> > index 4ef84c05c1..474322cc21 100644
> > --- a/libavformat/hlsenc.c
> > +++ b/libavformat/hlsenc.c
> > @@ -28,6 +28,8 @@
> >  #include <unistd.h>
> >  #endif
> >
> > +#include "float.h"
> > +
> >  #include "libavutil/avassert.h"
> >  #include "libavutil/mathematics.h"
> >  #include "libavutil/avstring.h"
> > @@ -212,6 +214,8 @@ typedef struct HLSContext {
> >      int64_t recording_time;
> >      int64_t max_seg_size; // every segment file max size
> >
> > +    double init_program_date_time;
> > +
> >      char *baseurl;
> >      char *vtt_format_options_str;
> >      char *subtitle_filename;
> > @@ -2867,7 +2871,7 @@ static int hls_init(AVFormatContext *s)
> >      char *p = NULL;
> >      int http_base_proto = ff_is_http_proto(s->url);
> >      int fmp4_init_filename_len = strlen(hls->fmp4_init_filename) + 1;
> > -    double initial_program_date_time = av_gettime() / 1000000.0;
> > +    double initial_program_date_time = hls->init_program_date_time ?
> hls->init_program_date_time : av_gettime() / 1000000.0;
> >
> >      if (hls->use_localtime) {
> >          pattern = get_default_pattern_localtime_fmt(s);
> > @@ -3141,6 +3145,7 @@ static const AVOption options[] = {
> >      {"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"},
> > +    {"init_program_date_time", "Time to start program date time at",
> OFFSET(init_program_date_time), AV_OPT_TYPE_DOUBLE, {.dbl = 0 }, 0,
> DBL_MAX,   E},
>
> This should probably not be mixed into the flags options list.
>
> It seems odd to have the user provide a double here instead of a ISO 8601
> datetime, which is what the spec requires / ends up in the playlist.
> If you do not want to handle the datetime string parsing, at least it
> would be good to give a hint what exactly the double value is expected to
> be here.
>
> However usability-wise I would prefer to accept a proper date/time here…
>

Is there an example of how to accept a string as the option and then do the
parsing that I could base the code on?