From: Li Kai <wolfleekay@gmail.com>
To: FFmpeg development discussions and patches <ffmpeg-devel@ffmpeg.org>
Cc: Steven Liu <lingjiujianke@gmail.com>
Subject: Re: [FFmpeg-devel] [PATCH] avformat/hls:use EXT-X-START instead of live_start_index if it's in playlist
Date: Sat, 25 Jun 2022 22:15:29 +0800
Message-ID: <CACGufqSYj=OzFefuu9g=1n3AWrrQ3neSqGTyKdTZ95dSXr1MJg@mail.gmail.com> (raw)
In-Reply-To: <A1D72545-50CD-489E-8CC8-A4914097B7BB@chinaffmpeg.org>
[-- Attachment #1: Type: text/plain, Size: 23469 bytes --]
OK, I add the option description in doc/demuxers.texi.
About invalid EXT-X-START value, it's not played on Safari.
So I make it error to handle.
You opinion, it's better way. The latest patch fix it.
On 2022/6/25 21:26, Steven Liu wrote:
>
>
>> 在 2022年6月25日，13:24，Li Kai <wolfleekay@gmail.com> 写道：
>>
>> Ok, I add allowed_x_start option, and the option default is 0. So current
> What about use “prefer_x_start” for option name.
>
> BTW, add option descriptions into document doc/demuxers.texi
>
>
> + } 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;
> + }
>
> should this logic goto fail?
> why don’t output a warning and continue try to use live_start_index? Or
maybe there have some reason, are they?
>> users will not be affected.
>> please review again.
>>
>> At last, Thanks your tips.
>>
>> Steven Liu <lq@chinaffmpeg.org> 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 <wolfleekay@gmail.com> 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 <lingjiujianke@gmail.com> 于2022年6月24日周五 14:21写道：
>>>>
>>>>> 少宇李 <wolfleekay@gmail.com> 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".
>>>
>>
<v2-0001-avformat-hls-add-EXT-X-START-tag-support-by-allow.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".
Steven Liu <lq@chinaffmpeg.org> 于2022年6月25日周六 21:28写道：
>
>
> > 在 2022年6月25日，13:24，Li Kai <wolfleekay@gmail.com> 写道：
> >
> > Ok, I add allowed_x_start option, and the option default is 0. So current
> What about use “prefer_x_start” for option name.
>
> BTW, add option descriptions into document doc/demuxers.texi
>
>
> + } 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;
> + }
>
> should this logic goto fail?
> why don’t output a warning and continue try to use live_start_index? Or
> maybe there have some reason, are they?
> > users will not be affected.
> > please review again.
> >
> > At last, Thanks your tips.
> >
> > Steven Liu <lq@chinaffmpeg.org> 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 <wolfleekay@gmail.com> 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 <lingjiujianke@gmail.com> 于2022年6月24日周五 14:21写道：
> >>>
> >>>> 少宇李 <wolfleekay@gmail.com> 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".
> >>
> >
> <v2-0001-avformat-hls-add-EXT-X-START-tag-support-by-allow.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
>
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[-- Attachment #2: v3-0001-avformat-hls-add-EXT-X-START-tag-support-by-allow.patch --]
[-- Type: text/x-patch, Size: 5961 bytes --]
From cd5d1f2d45148dc97ad23252a13a4e93898d2ac3 Mon Sep 17 00:00:00 2001
From: Li Kai <wolfleekay@gmail.com>
Date: Thu, 23 Jun 2022 00:55:38 +0800
Subject: [PATCH v3] avformat/hls: add #EXT-X-START tag support by
prefer_x_start opt
Signed-off-by: Li Kai <wolfleekay@gmail.com>
---
doc/demuxers.texi | 3 +++
libavformat/hls.c | 60 +++++++++++++++++++++++++++++++++++++++++++++--
2 files changed, 61 insertions(+), 2 deletions(-)
diff --git a/doc/demuxers.texi b/doc/demuxers.texi
index c95a9ae594..2b6dd86c2a 100644
--- a/doc/demuxers.texi
+++ b/doc/demuxers.texi
@@ -373,6 +373,9 @@ It accepts the following options:
@item live_start_index
segment index to start live streams at (negative values are from the end).
+@item prefer_x_start
+prefer to use #EXT-X-START if it's in playlist instead of live_start_index.
+
@item allowed_extensions
',' separated list of file extensions that hls is allowed to access.
diff --git a/libavformat/hls.c b/libavformat/hls.c
index 8204f55df3..86e5d5a629 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;
@@ -211,6 +213,7 @@ typedef struct HLSContext {
int64_t cur_seq_no;
int m3u8_hold_counters;
int live_start_index;
+ int prefer_x_start;
int first_packet;
int64_t first_timestamp;
int64_t cur_timestamp;
@@ -741,6 +744,7 @@ 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 +893,20 @@ 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 {
+ av_log(c->ctx, AV_LOG_WARNING, "#EXT-X-START value is"
+ "invalid, it will be ignored");
+ continue;
+ }
} else if (av_strstart(line, "#EXT-X-ENDLIST", &ptr)) {
if (pls)
pls->finished = 1;
@@ -1722,9 +1740,45 @@ 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);
+ seq_no = 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);
+ seq_no = pls->start_seq_no + FFMIN(c->live_start_index,
+ pls->n_segments - 1);
+
+ /* If #EXT-X-START in playlist, need to recalculate */
+ if (pls->time_offset_flag && c->prefer_x_start) {
+ int64_t start_timestamp;
+ int64_t playlist_duration = 0;
+ int64_t cur_timestamp = c->cur_timestamp == AV_NOPTS_VALUE ? 0 :
+ c->cur_timestamp;
+
+ for (int 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);
+ }
+ return seq_no;
}
/* Otherwise just start on the first segment. */
@@ -2476,6 +2530,8 @@ static int hls_probe(const AVProbeData *p)
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},
+ {"prefer_x_start", "prefer to use #EXT-X-START if it's in playlist instead of live_start_index",
+ OFFSET(prefer_x_start), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, FLAGS},
{"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"},
--
2.25.1
[-- Attachment #3: Type: text/plain, Size: 251 bytes --]
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next prev parent reply other threads:[~2022-06-25 14:15 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-23 15:00 wolfleekay
2022-06-24 1:50 ` Steven Liu
2022-06-24 3:58 ` 少宇李
2022-06-24 6:21 ` Steven Liu
2022-06-25 4:32 ` 少宇李
2022-06-25 4:51 ` Steven Liu
2022-06-25 5:23 ` Li Kai
2022-06-25 5:24 ` Li Kai
2022-06-25 13:26 ` Steven Liu
2022-06-25 14:15 ` Li Kai [this message]
2022-06-27 2:23 ` Steven Liu
2022-06-27 2:58 ` Li Kai
2022-06-27 3:05 ` Steven Liu
2022-06-29 4:17 ` Steven Liu
2022-06-24 16:44 Li Kai
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