> On Aug 6, 2018, at 19:29, Ronak Patel <ronak2121-at-yahoo....@ffmpeg.org>
> wrote:
>
>>
>> On Aug 6, 2018, at 7:19 AM, Liu Steven <l...@chinaffmpeg.org> wrote:
>>
>>
>>
>>>> 在 2018年8月6日，下午7:12，Ronak Patel <ronak2121-at-yahoo....@ffmpeg.org> 写道：
>>>>
>>>>
>>>> On Aug 5, 2018, at 10:54 PM, Liu Steven <l...@chinaffmpeg.org> wrote:
>>>>
>>>>
>>>>
>>>>> 在 2018年8月4日，上午2:17，Ronak <ronak2...@yahoo.com> 写道：
>>>>>
>>>>>>>>>>> I have read this patch some problem for this patch.
>>>>>>>>>>>
>>>>>>>>>>> 1. maybe there will have a problem when duration is not same when
>>>>>>>>>>> every fragment, for example:
>>>>>>>>>>> liuqideMacBook-Pro:xxx liuqi$ ./ffmpeg -v quiet -i
>>>>>>>>>>> ~/Movies/Test/bbb_sunflower_1080p_30fps_normal.mp4 -c copy -f hls
>>>>>>>>>>> -hls_list_size 0 output_test.m3u8
>>>>>>>>>>> liuqideMacBook-Pro:xxx liuqi$ head -n 10 output_test.m3u8
>>>>>>>>>>> #EXTM3U
>>>>>>>>>>> #EXT-X-VERSION:3
>>>>>>>>>>> #EXT-X-TARGETDURATION:8
>>>>>>>>>>> #EXT-X-MEDIA-SEQUENCE:0
>>>>>>>>>>> #EXTINF:3.866667,
>>>>>>>>>>> output_test0.ts
>>>>>>>>>>> #EXTINF:7.300000,
>>>>>>>>>>> output_test1.ts
>>>>>>>>>>> #EXTINF:8.333333,
>>>>>>>>>>> output_test2.ts
>>>>>>>>>>>
>>>>>>>>>>> the output_test0.ts’s duration is short than output_test1.ts, the
>>>>>>>>>>> #EXT-X-TARGETDURATION need update to the longest duration.
>>>>>>>>>>> this operation (check the longest duration) will happen at every
>>>>>>>>>>> fragment write complete.
>>>>>>>>>>> it will not update when move the update option to the
>>>>>>>>>>> hls_write_header,
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> This is a problem in the code that splits the mpegts files. I've
>>>>>>>>>> filed a separate issue for this here:
>>>>>>>>>> https://trac.ffmpeg.org/ticket/7341. Mpegts segmentation should be
>>>>>>>>>> following the hls_time parameter (or the default length).
>>>>>>>>> This is whatever hls_time, is decide by keyframe position, this is
>>>>>>>>> happen when GOP size is not a permanent t position.
>>>>>>>>>
>>>>>>
>>>>>>>>>> This is happening now with fMP4 assets, but not with mpegts.
>>>>>>>>> Whatever fmp4 or mpegts, all of them need fix the problem of duration
>>>>>>>>> refresh.
>>>>>>>>>
>>>>>>>>> for example:
>>>>>>>>>
>>>>>>>>> liuqideMacBook-Pro:xxx liuqi$ ./ffmpeg -ss -v quiet -i
>>>>>>>>> ~/Movies/Test/bbb_sunflower_1080p_30fps_normal.mp4 -c copy -f hls
>>>>>>>>> -hls_list_size 0 -hls_segment_type fmp4 -hls_time 3 output_test.m3u8
>>>>>>>>> liuqideMacBook-Pro:xxx liuqi$ head -n 10 output_test.m3u8
>>>>>>>>> #EXTM3U
>>>>>>>>> #EXT-X-VERSION:7
>>>>>>>>> #EXT-X-TARGETDURATION:8
>>>>>>>>> #EXT-X-MEDIA-SEQUENCE:0
>>>>>>>>> #EXT-X-MAP:URI="init.mp4"
>>>>>>>>> #EXTINF:3.866667,
>>>>>>>>> output_test0.m4s
>>>>>>>>> #EXTINF:7.300000,
>>>>>>>>> output_test1.m4s
>>>>>>>>> #EXTINF:8.333333,
>>>>>>>>> liuqideMacBook-Pro:xxx liuqi$
>>>>>>>>
>>>>>>>> This is after your patch:
>>>>>>>> liuqideMacBook-Pro:xxx liuqi$ ./ffmpeg -ss 17 -v quiet -i
>>>>>>>> ~/Movies/Test/bbb_sunflower_1080p_30fps_normal.mp4 -c copy -f hls
>>>>>>>> -hls_list_size 0 -hls_segment_type fmp4 -hls_time 3 output_test.m3u8
>>>>>>>> liuqideMacBook-Pro:xxx liuqi$ head -n 10 output_test.m3u8
>>>>>>>> #EXTM3U
>>>>>>>> #EXT-X-VERSION:7
>>>>>>>> #EXT-X-TARGETDURATION:3
>>>>>>>> #EXT-X-MEDIA-SEQUENCE:0
>>>>>>>> #EXT-X-MAP:URI="init.mp4"
>>>>>>>> #EXTINF:3.866667,
>>>>>>>> output_test0.m4s
>>>>>>>> #EXTINF:7.300000,
>>>>>>>> output_test1.m4s
>>>>>>>> #EXTINF:8.333333,
>>>>>>>>
>>>>>>>> The RFC https://www.rfc-editor.org/rfc/rfc8216.txt describe:
>>>>>>>>
>>>>>>>> 4.3.3.1. EXT-X-TARGETDURATION
>>>>>>>>
>>>>>>>> The EXT-X-TARGETDURATION tag specifies the maximum Media Segment
>>>>>>>> duration. The EXTINF duration of each Media Segment in the Playlist
>>>>>>>> file, when rounded to the nearest integer, MUST be less than or equal
>>>>>>>> to the target duration; longer segments can trigger playback stalls
>>>>>>>> or other errors. It applies to the entire Playlist file. Its format
>>>>>>>> is:
>>>>>>>>
>>>>>>>> #EXT-X-TARGETDURATION:<s>
>>>>>>>>
>>>>>>>> where s is a decimal-integer indicating the target duration in
>>>>>>>> seconds. The EXT-X-TARGETDURATION tag is REQUIRED.
>>>>>>>>
>>>>>>>> your patch make the EXT-X-TARGETDURATION less than EXTINF:7.300000
>>>>>>>> EXTINF:8.333333
>>>>>>>
>>>>>>>
>>>>>>>>>>> 2. the version maybe will update when use hls_segment_type or
>>>>>>>>>>> append_list etc. when the operation is support from different
>>>>>>>>>>> version m3u8.
>>>>>>>>>>
>>>>>>>>>> I don't follow what you mean here. The version number is known up
>>>>>>>>>> front, based on the options that were passed in. It should be
>>>>>>>>>> illegal to switch between versions when trying to update an existing
>>>>>>>>>> manifest. When can this legitimately happen?
>>>>>>>>> there maybe have some player cannot support high version of m3u8, for
>>>>>>>>> example old parser or player just support the VERSION 3,
>>>>>>>>> this must think about all of the player or parser, because ffmpeg is
>>>>>>>>> not used only by myself.
>>>>>>>>>
>>>>>>>>> Or what about get the #EXT-X-VERSION position, to update it? looks
>>>>>>>>> like flvenc.c or movenc.c date shift
>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>> 3. need update segments vs->segments when hls_list_size option is
>>>>>>>>>>> set.
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> What do you mean by this and where should I do it?
>>>>>>>>> for example, hls_list_size is 4, the m3u8 list should refresh every
>>>>>>>>> time when make a new fragment.
>>>>>>>>>
>>>>>>>>> first time:
>>>>>>>>> 1.m4s
>>>>>>>>> 2.m4s
>>>>>>>>> 3.m4s
>>>>>>>>> 4.m4s
>>>>>>>>>
>>>>>>>>> sencond time:
>>>>>>>>> 2.m4s
>>>>>>>>> 3.m4s
>>>>>>>>> 4.m4s
>>>>>>>>> 5.m4s
>>>>>>>>
>>>>>>>> after your patch:
>>>>>>>>
>>>>>>>> liuqideMacBook-Pro:xxx liuqi$ ./ffmpeg -v quiet -i
>>>>>>>> ~/Movies/Test/bbb_sunflower_1080p_30fps_normal.mp4 -c copy -f hls
>>>>>>>> -hls_list_size 4 -hls_segment_type fmp4 -hls_time 3 -t 50
>>>>>>>> output_test.m3u8
>>>>>>>> liuqideMacBook-Pro:xxx liuqi$ cat output_test.m3u8
>>>>>>>> #EXTM3U
>>>>>>>> #EXT-X-VERSION:7
>>>>>>>> #EXT-X-TARGETDURATION:3
>>>>>>>> #EXT-X-MEDIA-SEQUENCE:0
>>>>>>>> #EXT-X-MAP:URI="init.mp4"
>>>>>>>> #EXTINF:3.866667,
>>>>>>>> output_test0.m4s
>>>>>>>> #EXTINF:7.300000,
>>>>>>>> output_test1.m4s
>>>>>>>> #EXTINF:8.333333,
>>>>>>>> output_test2.m4s
>>>>>>>> #EXTINF:3.966667,
>>>>>>>> output_test3.m4s
>>>>>>>> #EXTINF:8.333333,
>>>>>>>> output_test4.m4s
>>>>>>>> #EXTINF:4.033333,
>>>>>>>> output_test5.m4s
>>>>>>>> #EXTINF:8.333333,
>>>>>>>> output_test6.m4s
>>>>>>>> #EXTINF:4.633333,
>>>>>>>> output_test7.m4s
>>>>>>>> liuqideMacBook-Pro:xxx liuqi$
>>>>>>>> liuqideMacBook-Pro:xxx liuqi$
>>>>>>>>
>>>>>>>> the m3u8 list is incorrect, because users want control the m3u8 list
>>>>>>>> length, because their disk do not have enough space to save the
>>>>>>>> fragments.
>>>>>>>>
>>>>>>>
>>>>>>> Ok I will fix this.
>>>>>
>>>>>
>>>>> I'm attaching a new patch that resolves all of these issues, while still
>>>>> resolving this bug for VOD playlists.
>>>>>
>>>>> Can you please review?
>>>>>
>>>>>
>>>>> <0001-libavformat-hlsenc-Fix-HLS-Manifest-Generation-from-.patch>
>>>>
>>>> From bbc4870c0d685f5c07e82042c3f2ef153d83f3d1 Mon Sep 17 00:00:00 2001
>>>> From: "Ronak Patel (Audible)" <ron...@audible.com>
>>>> Date: Thu, 2 Aug 2018 09:25:12 -0400
>>>> Subject: [PATCH] libavformat/hlsenc: Fix HLS Manifest Generation from an
>>>> N^2
>>>> algorithm to N.
>>>>
>>>> This fixes the creation of the hls manifest in hlsenc.c by writing the
>>>> entire manifest at the end for VOD playlists. Live & Event Playlists are
>>>> unaffected.
>>>> This also fixes the behavior with HLS_TEMP_FILE to work correctly when
>>>> -hlsflags temp_file is specified, instead of always relying on use_rename,
>>>> which caused these problems.
>>>>
>>>> Files that would previously take over a week to fragment now take 1 minute
>>>> on the same hardware. This was a 153 hour audio file (2.2GB of audio).
>>>>
>>>> Signed-off-by: Ronak Patel <ronak2...@yahoo.com>
>>>> ---
>>>> libavformat/dashenc.c | 2 +-
>>>> libavformat/hlsenc.c | 54
>>>> +++++++++++++++++++++++++++++++++------------------
>>>> 2 files changed, 36 insertions(+), 20 deletions(-)
>>>>
>>>> diff --git a/libavformat/dashenc.c b/libavformat/dashenc.c
>>>>
>>>> -------you have modify dash
>>>
>>> Sorry I will submit this separately. Will remove.
>>>
>>>> index ae57fd5..ae22c08 100644
>>>> --- a/libavformat/dashenc.c
>>>> +++ b/libavformat/dashenc.c
>>>> @@ -483,7 +483,7 @@ static void output_segment_list(OutputStream *os,
>>>> AVIOContext *out, AVFormatCont
>>>> target_duration = lrint(duration);
>>>> }
>>>>
>>>> - ff_hls_write_playlist_header(c->m3u8_out, 6, -1, target_duration,
>>>> + ff_hls_write_playlist_header(c->m3u8_out, 7, -1, target_duration,
>>>> start_number, PLAYLIST_TYPE_NONE);
>>>>
>>>> ff_hls_write_init_file(c->m3u8_out, os->initfile, c->single_file,
>>>> diff --git a/libavformat/hlsenc.c b/libavformat/hlsenc.c
>>>> index b5644f0..0eb0801 100644
>>>> --- a/libavformat/hlsenc.c
>>>> +++ b/libavformat/hlsenc.c
>>>> @@ -942,6 +942,7 @@ static int
>>>> sls_flag_use_localtime_filename(AVFormatContext *oc, HLSContext *c, V
>>>> if (c->flags & (HLS_SECOND_LEVEL_SEGMENT_SIZE |
>>>> HLS_SECOND_LEVEL_SEGMENT_DURATION)) {
>>>> av_strlcpy(vs->current_segment_final_filename_fmt, oc->url,
>>>> sizeof(vs->current_segment_final_filename_fmt));
>>>> +
>>>> ——you add a empty line
>>> Ok will remove
>>>
>>>> if (c->flags & HLS_SECOND_LEVEL_SEGMENT_SIZE) {
>>>> char *filename = NULL;
>>>> if (replace_int_data_in_filename(&filename, oc->url, 's', 0) < 1)
>>>> {
>>>> @@ -1166,9 +1167,10 @@ static int hls_rename_temp_file(AVFormatContext *s,
>>>> AVFormatContext *oc)
>>>>
>>>> if (!final_filename)
>>>> return AVERROR(ENOMEM);
>>>> +
>>>> ——you add a empty line
>>> Ok will remove
>>>>
>>>> final_filename[len-4] = '\0';
>>>> +
>>>>
>>>> ——you add a empty line
>>> Ok will remove
>>>> ret = ff_rename(oc->url, final_filename, s);
>>>> - oc->url[len-4] = '\0’;
>>>> ——Why do you give the len - 4 = 0?
>>> This code was already there. All I’m doing is removing this part that was
>>> causing a problem when you use the HLS_TEMP option.
>>>
>>>> av_freep(&final_filename);
>>>> return ret;
>>>> }
>>>> @@ -1373,9 +1375,7 @@ static int hls_window(AVFormatContext *s, int last,
>>>> VariantStream *vs)
>>>> int ret = 0;
>>>> char temp_filename[1024];
>>>> int64_t sequence = FFMAX(hls->start_sequence, vs->sequence -
>>>> vs->nb_entries);
>>>> - const char *proto = avio_find_protocol_name(s->url);
>>>> - int use_rename = proto && !strcmp(proto, "file");
>>>> - static unsigned warned_non_file;
>>>> + int use_temp_file = (s->flags & HLS_TEMP_FILE);
>>>> ——What will have if use http put method?
>>>
>>> I’ll test it.
>>>
>>>> char *key_uri = NULL;
>>>> char *iv_string = NULL;
>>>> AVDictionary *options = NULL;
>>>> @@ -1397,11 +1397,9 @@ static int hls_window(AVFormatContext *s, int last,
>>>> VariantStream *vs)
>>>> hls->version = 7;
>>>> }
>>>>
>>>> - if (!use_rename && !warned_non_file++)
>>>> - av_log(s, AV_LOG_ERROR, "Cannot use rename on non file protocol,
>>>> this may lead to races and temporary partial files\n");
>>>> -
>>>> ——I have see this message long time, i have not remove this message
>>>> because this is used to http method. Why do you remove it?
>>>
>>> I can keep it for http put and HLS_TEMP if that’s what you want.
>>>
>>>>
>>>> set_http_options(s, &options, hls);
>>>> - snprintf(temp_filename, sizeof(temp_filename), use_rename ? "%s.tmp"
>>>> : "%s", vs->m3u8_name);
>>>> + snprintf(temp_filename, sizeof(temp_filename), use_temp_file ?
>>>> "%s.tmp" : "%s", vs->m3u8_name);
>>>> + //av_log(s, AV_LOG_INFO, "We're going to write out to %s",
>>>> temp_filename);
>>>> ------this info message is unused?
>>>
>>> Ok will remove.
>>>
>>>> if ((ret = hlsenc_io_open(s, has->m3u8_out, temp_filename, &options)) < 0)
>>>> goto fail;
>>>>
>>>> @@ -1472,8 +1470,9 @@ fail:
>>>> av_dict_free(&options);
>>>> hlsenc_io_close(s, &hls->m3u8_out, temp_filename);
>>>> hlsenc_io_close(s, &hls->sub_m3u8_out, vs->vtt_m3u8_name);
>>>> - if (ret >= 0 && use_rename)
>>>> - ff_rename(temp_filename, vs->m3u8_name, s);
>>>> + if (use_temp_file) {
>>>> + ff_rename(temp_filename, vs->m3u8_name, s);
>>>> + }
>>>>
>>>> if (ret >= 0 && hls->master_pl_name)
>>>> if (create_master_playlist(s, vs) < 0)
>>>> @@ -2253,11 +2252,14 @@ static int hls_write_packet(AVFormatContext *s,
>>>> AVPacket *pkt)
>>>> hlsenc_io_close(s, &vs->vtt_avf->pb, vs->vtt_avf->url);
>>>> }
>>>> }
>>>> +
>>>> + // look to rename the asset name
>>>> if ((hls->flags & HLS_TEMP_FILE) && oc->url[0]) {
>>>> - if (!(hls->flags & HLS_SINGLE_FILE) || (hls->max_seg_size <=
>>>> 0))
>>>> - if ((vs->avf->oformat->priv_class && vs->avf->priv_data)
>>>> && hls->segment_type != SEGMENT_TYPE_FMP4)
>>>> - av_opt_set(vs->avf->priv_data, "mpegts_flags",
>>>> "resend_headers", 0);
>>>> - hls_rename_temp_file(s, oc);
>>>> + if (!(hls->flags & HLS_SINGLE_FILE) || (hls->max_seg_size <=
>>>> 0)) {
>>>> + if ((vs->avf->oformat->priv_class && vs->avf->priv_data)
>>>> && hls->segment_type != SEGMENT_TYPE_FMP4) {
>>>> + av_opt_set(vs->avf->priv_data, "mpegts_flags",
>>>> "resend_headers", 0);
>>>> + }
>>>> + }
>>>> ——Just reindent?
>>>
>>> Yes I put the code properly under braces. But if you don’t like it, I can
>>> remove.
>>>
>>>> }
>>>>
>>>> if (vs->fmp4_init_mode) {
>>>> @@ -2286,6 +2288,17 @@ static int hls_write_packet(AVFormatContext *s,
>>>> AVPacket *pkt)
>>>> return ret;
>>>> }
>>>> ff_format_io_close(s, &vs->out);
>>>> +
>>>> + // rename that segment from .tmp to the real one
>>>> + if ((hls->flags & HLS_TEMP_FILE) && oc->url[0]) {
>>>> + hls_rename_temp_file(s, oc);
>>>> + av_free(old_filename);
>>>> + old_filename = av_strdup(vs->avf->url);
>>>> +
>>>> + if (!old_filename) {
>>>> + return AVERROR(ENOMEM);
>>>> + }
>>>> + }
>>>> }
>>>> }
>>>>
>>>> @@ -2334,14 +2347,16 @@ static int hls_write_packet(AVFormatContext *s,
>>>> AVPacket *pkt)
>>>> return ret;
>>>> }
>>>>
>>>> - if (!vs->fmp4_init_mode || byterange_mode)
>>>> + // if we're building a VOD playlist, skip writing the manifest
>>>> multiple times, and just wait until the end
>>>> + if (hls->pl_type != PLAYLIST_TYPE_VOD) {
>>>> ------Whatever event VOD or Live Streaming, the EXT-X-TARGETDURATION need
>>>> refresh when lrint(current fragment duration) is large than lrint(the
>>>> before duration).
>>>
>>> You do not need to do this for VOD. This is the main reason why ffmpeg
>>> takes over 7 days to fragment a 153 hour VOD audio file. Other tools can do
>>> it in less than 5 minutes. Why would you write the same VOD playlist over
>>> 155000 times on disk when the input is never changing.
>>>
>>> VOD does not ever change once it is written so it makes sense to wait until
>>> the very end to write out the entire manifest. There’s no refreshing
>>> required. Only live or event playlists need any sort of refresh. Ffmpeg is
>>> written predominantly for the event or live use case I’ve noticed, which
>>> has forced you to make poor decisions for VOD.
>>>
>>> If I could I would rewrite all of this logic to clearly separate VOD from
>>> event and live playlist generation logic to make the code clearer. This is
>>> hard to understand code in general.
>>
>> Maybe you want record the fragments to a VOD Service, or time shift for the
>> history stream. Do i guess right or wrong?
>>>
>
> If that’s what you want, you would wait until the very end anyway. Why would
> you upload a partial manifest file?
>
> For VOD, you don’t do anything until you get the whole manifest. If you
> wanted a partial one, that’s an event, and you can pass that option to get
> the refreshing behavior.
>
> Even with event, this algorithm of writing out the entire manifest just to
> add a new segment is very wasteful, slow and unnecessary. This is an O(N!)
> algorithm for something you can solve in O(N) time. You can just append and
> adjust the EXT-X-TARGETDURATION for your video content.
Yes, I agreed with you and cannot agreed more. O(N!), but is the list is too
short, that is not a problem. But, why do you create a list long time to 7
days? The hls_list_size default is 5 fragments, and the hls live streaming (No
Endlist) is play from last 3 fragment, i can not understand what do you want.
let me make sure, do you want record long list? or maybe you want make some
files to use disk?
>
>>>>
>>>> if ((ret = hls_window(s, 0, vs)) < 0) {
>>>> return ret;
>>>> }
>>>> + }
>>>> }
>>>>
>>>> - vs->packets_written++;
>>>> ret = ff_write_chained(oc, stream_index, pkt, s, 0);
>>>> + vs->packets_written++;
>>>>
>>>> return ret;
>>>> }
>>>> @@ -2394,15 +2409,16 @@ failed:
>>>> if (hls->segment_type != SEGMENT_TYPE_FMP4)
>>>> ff_format_io_close(s, &oc->pb);
>>>>
>>>> - if ((hls->flags & HLS_TEMP_FILE) && oc->url[0]) {
>>>> - hls_rename_temp_file(s, oc);
>>>> + // rename that segment from .tmp to the real one
>>>> + if ((hls->flags & HLS_TEMP_FILE) && oc->url[0] &&
>>>> !(hls->flags & HLS_SINGLE_FILE)) {
>>>> + hls_rename_temp_file(s, oc);
>>>> av_free(old_filename);
>>>> old_filename = av_strdup(vs->avf->url);
>>>>
>>>> if (!old_filename) {
>>>> return AVERROR(ENOMEM);
>>>> }
>>>> - }
>>>> + }
>>>>
>>>> /* after av_write_trailer, then duration + 1 duration per packet
>>>> */
>>>> hls_append_segment(s, hls, vs, vs->duration + vs->dpp,
>>>> vs->start_pos, vs->size);
>>>> --
>>>> 2.6.3
>>>>
>>>>
>>>>>
>>>>
>>>>
>>>>
>>>>
Thanks
Steven
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