<wolflee...@gmail.com> 于2022年6月23日周四 23:01写道： > > From: Li Kai <wolflee...@gmail.com> Hi Li, > > Refer to https://datatracker.ietf.org/doc/html/rfc8216#section-4.3.5.2 > > Signed-off-by: Li Kai <wolflee...@gmail.com> > --- > libavformat/hls.c | 68 ++++++++++++++++++++++++++++++++++++++++++----- > 1 file changed, 62 insertions(+), 6 deletions(-) > > diff --git a/libavformat/hls.c b/libavformat/hls.c > index 8204f55df3..96923c3eac 100644 > --- a/libavformat/hls.c > +++ b/libavformat/hls.c > @@ -120,6 +120,8 @@ struct playlist { > enum PlaylistType type; > int64_t target_duration; > int64_t start_seq_no; > + int time_offset_flag; > + int64_t start_time_offset; > int n_segments; > struct segment **segments; > int needed; > @@ -741,6 +743,7 @@ static int parse_playlist(HLSContext *c, const char *url, > struct segment **prev_segments = NULL; > int prev_n_segments = 0; > int64_t prev_start_seq_no = -1; > + const char *p; > > if (is_http && !in && c->http_persistent && c->playlist_pb) { > in = c->playlist_pb; > @@ -889,6 +892,18 @@ static int parse_playlist(HLSContext *c, const char *url, > cur_init_section->key = NULL; > } > > + } else if (av_strstart(line, "#EXT-X-START:", &ptr)) { > + ret = ensure_playlist(c, &pls, url); > + if (ret < 0) { > + goto fail; > + } > + if (av_strstart(ptr, "TIME-OFFSET=", &p)) { > + float offset = strtof(p, NULL); > + pls->start_time_offset = offset * AV_TIME_BASE; > + pls->time_offset_flag = 1; > + } else { > + goto fail; > + } This part is refine hls function, but i prefer reserved old process way bellow. Support both way of them should be ok. > } else if (av_strstart(line, "#EXT-X-ENDLIST", &ptr)) { > if (pls) > pls->finished = 1; > @@ -1719,12 +1734,53 @@ static int64_t select_cur_seq_no(HLSContext *c, > struct playlist *pls) > * require us to download a segment to inspect its timestamps. */ > return c->cur_seq_no; > > - /* If this is a live stream, start live_start_index segments from the > - * start or end */ > - if (c->live_start_index < 0) > - return pls->start_seq_no + FFMAX(pls->n_segments + > c->live_start_index, 0); > - else > - return pls->start_seq_no + FFMIN(c->live_start_index, > pls->n_segments - 1); > + if (!pls->time_offset_flag) { > + /* If this is a live stream, start live_start_index segments > from the > + * start or end */ > + if (c->live_start_index < 0) This could be set by user from command line. It's not only used from play list, also can be controled by user. > + return pls->start_seq_no + FFMAX(pls->n_segments + > + c->live_start_index, 0); > + else > + return pls->start_seq_no + FFMIN(c->live_start_index, > + pls->n_segments - 1); > + } else { > + /* If playlist indicate a TIME-OFFSET, need to recalculate > seq_no */ > + int i; > + int64_t start_timestamp; > + int64_t playlist_duration = 0; > + int64_t cur_timestamp = c->cur_timestamp == AV_NOPTS_VALUE ? 0 : > + c->cur_timestamp; > + > + for (i = 0; i < pls->n_segments; i++) { > + playlist_duration += pls->segments[i]->duration; > + } > + /* If the absolute value of TIME-OFFSET exceeds > + * the duration of the Playlist, it indicates either the end of > the > + * Playlist (if positive) or the beginning of the Playlist (if > + * negative). */ > + if (pls->start_time_offset >=0 && > + pls->start_time_offset > playlist_duration) > + start_timestamp = cur_timestamp + playlist_duration; > + else if (pls->start_time_offset >= 0 && > + pls->start_time_offset <= playlist_duration) > + start_timestamp = cur_timestamp + pls->start_time_offset; > + else if (pls->start_time_offset < 0 && > + pls->start_time_offset < -playlist_duration) > + start_timestamp = cur_timestamp; > + else if (pls->start_time_offset < 0 && > + pls->start_time_offset > -playlist_duration) > + start_timestamp = cur_timestamp + playlist_duration + > + pls->start_time_offset; > + else > + start_timestamp = cur_timestamp; > + > + find_timestamp_in_playlist(c, pls, start_timestamp, &seq_no, > NULL); > + av_log(c, AV_LOG_DEBUG, "start_timestamp: %" PRId64 > + "cur_timestamp:%" PRId64 > + "cur_seq_no:%" PRId64 "\n", > + start_timestamp, cur_timestamp, seq_no); > + return seq_no; > + } > } > > /* Otherwise just start on the first segment. */ > -- > 2.25.1 > > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
Thanks Steven _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
