Ok, I add allowed_x_start option, and the option default is 0. So current users will not be affected. please review again. At last, Thanks your tips. Steven Liu 于2022年6月25日周六 12:51写道： > > > > 在 2022年6月25日，12:32，少宇李 写道： > > > > Hi Steven, > > > > Please review code. > > > > I changed code, but I still have a question. > > If EXT-X-START tag in playlist and users set live_start_index, the > > live_start_index will not work > > for current codes, which makes maybe users confused. > > Is that OK? > for current codes, user cannot aware there have EXT-X-START tag in the > playlist, so i think we should reserve the old use method. > or maybe you can add an option for user to decide which way they can use > (either EXT-X-START or live_start_index). > Because there should have many people using live_start_index for 'time > shift’ by player (user control), > > > > > In other hand, if make live_start_index valid when EXT-X-START tag in > > playlist, maybe live_start_index needs a flag, or > > make live_start_index default value is INT_MIN to distinguish. > > becuase the live_start_index default value is -3, I have no idea to > > distinguish users action or > > default value when live_start_index=-3. > yes cannot distinguish users action, but user should can decided use > live_start_index or EXT-X-START. > > > > > May I need to set default value=INT_MIN as live_start_index default > value? > > And only when does not exist EXT-X-START > > tag in playlist, make live_start_index = -3 or users's configuration > value. > > I have no idea which is better~ > > > > Thanks a lot! > > > > Steven Liu 于2022年6月24日周五 14:21写道： > > > >> 少宇李 于2022年6月24日周五 11:58写道： > >>>> > >>>> > >>>> Hi, Steven > >>> > >>> > >>> I got it. > >>> > >>> User could use "live_start_index" option even if #EXT-X-START in the > >> playlist. > >>> > >>> I changed the priority about #EXT-X-START/live_start_index, > >>> > >>> this is new bellow: > >>> > >>> --- > >>> libavformat/hls.c | 69 +++++++++++++++++++++++++++++++++++++++++++---- > >>> 1 file changed, 64 insertions(+), 5 deletions(-) > >>> > >>> diff --git a/libavformat/hls.c b/libavformat/hls.c > >>> index b736f093a9..309471efce 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; > >>> + } > >>> } else if (av_strstart(line, "#EXT-X-ENDLIST", &ptr)) { > >>> if (pls) > >>> pls->finished = 1; > >>> @@ -1721,10 +1736,54 @@ static int64_t select_cur_seq_no(HLSContext *c, > >> struct playlist *pls) > >>> > >>> /* 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 (c->live_start_index != INT_MIN) { > >> Maybe you should not change current logic. > >> You can just add about process EXT-X-START sence,. > >> For example: > >> compute the start_seq_no and save the value to a temp varible and > >> don't return immediately, check the third scence which get EXT-X-START > >> tag from playlist. > >> process the temp varible after start_seq_no compute from > >> live_start_index or EXT-X-START. > >> > >>> + 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); > >>> + } else if (c->live_start_index == INT_MIN && > >> !pls->time_offset_flag) { > >>> + return pls->start_seq_no + FFMAX(pls->n_segments - 3, 0); > >>> + } else { > >>> + /* If playlist indicate a TIME-OFFSET and user not use > >> live_start_index, > >>> + * 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. */ > >>> @@ -2475,7 +2534,7 @@ static int hls_probe(const AVProbeData *p) > >>> #define FLAGS AV_OPT_FLAG_DECODING_PARAM > >>> static const AVOption hls_options[] = { > >>> {"live_start_index", "segment index to start live streams at > >> (negative values are from the end)", > >>> - OFFSET(live_start_index), AV_OPT_TYPE_INT, {.i64 = -3}, > >> INT_MIN, INT_MAX, FLAGS}, > >>> + OFFSET(live_start_index), AV_OPT_TYPE_INT, {.i64 = INT_MIN}, > >> INT_MIN, INT_MAX, FLAGS}, > >> This is unnecessary， because the default -3 is ok and be using by > >> users from many years ago. > >> > >>> {"allowed_extensions", "List of file extensions that hls is allowed > >> to access", > >>> OFFSET(allowed_extensions), AV_OPT_TYPE_STRING, > >>> {.str = > >> > "3gp,aac,avi,ac3,eac3,flac,mkv,m3u8,m4a,m4s,m4v,mpg,mov,mp2,mp3,mp4,mpeg,mpegts,ogg,ogv,oga,ts,vob,wav"}, > >>> -- > >>> 2.24.1 (Apple Git-126) > >>> > >>> > >>> Thanks Steven > >> > > > <0001-avformat-hls-use-EXT-X-START-instead-of-live_start_i.patch>_______________________________________________ > > ffmpeg-devel mailing list > > ffmpeg-devel@ffmpeg.org > > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > > > To unsubscribe, visit link above, or email > > ffmpeg-devel-request@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-request@ffmpeg.org with subject "unsubscribe". >