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.
