[FFmpeg-devel] First Patch for hlsenc.c for https://trac.ffmpeg.org/ticket/7281

Steven Liu lq at chinaffmpeg.org
Thu Aug 2 02:30:32 EEST 2018



> On Aug 2, 2018, at 07:22, Steven Liu <lq at chinaffmpeg.org> wrote:
> 
> 
> 
>> On Aug 2, 2018, at 06:20, Ronak <ronak2121 at yahoo.com> wrote:
>> 
>>> 
>>> On Aug 1, 2018, at 4:41 PM, Steven Liu <lq at chinaffmpeg.org> wrote:
>>> 
>>> 
>>> 
>>>> On Aug 2, 2018, at 03:50, Ronak <ronak2121-at-yahoo.com at ffmpeg.org> wrote:
>>>> 
>>>> <0001-libavformat-hlsenc-Fix-HLS-Manifest-Generation-from-.patch>
>>> From e7ff03ed52c709d647a112833427b44c41e3ed12 Mon Sep 17 00:00:00 2001
>>> From: "Ronak Patel (Audible)" <ronakp at audible.com>
>>> Date: Tue, 31 Jul 2018 19:05:18 -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 header once in hls_write_header, and the segments individually in the hls_window method.
>>> 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 <ronak2121 at yahoo.com>
>>> ---
>>> libavformat/hlsenc.c | 143 +++++++++++++++++++++++++++------------------------
>>> 1 file changed, 76 insertions(+), 67 deletions(-)
>>> 
>>> diff --git a/libavformat/hlsenc.c b/libavformat/hlsenc.c
>>> index b5644f0..b15645d 100644
>>> --- a/libavformat/hlsenc.c
>>> +++ b/libavformat/hlsenc.c
>>> @@ -488,7 +488,6 @@ static int hls_delete_old_segments(AVFormatContext *s, HLSContext *hls,
>>>        }
>>>        p = (char *)av_basename(dirname);
>>>        *p = '\0';
>>> -
>>>    }
>>> 
>>>    while (segment) {
>>> @@ -1365,63 +1364,37 @@ fail:
>>>    return ret;
>>> }
>>> 
>>> -static int hls_window(AVFormatContext *s, int last, VariantStream *vs)
>>> +static int hls_write_manifest_segment(AVFormatContext *s, int last, VariantStream *vs)
>>> {
>>>    HLSContext *hls = s->priv_data;
>>>    HLSSegment *en;
>>> -    int target_duration = 0;
>>>    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 byterange_mode;
>>>    char *key_uri = NULL;
>>>    char *iv_string = NULL;
>>>    AVDictionary *options = NULL;
>>>    double prog_date_time = vs->initial_prog_date_time;
>>>    double *prog_date_time_p = (hls->flags & HLS_PROGRAM_DATE_TIME) ? &prog_date_time : NULL;
>>> -    int byterange_mode = (hls->flags & HLS_SINGLE_FILE) || (hls->max_seg_size > 0);
>>> -
>>> -    hls->version = 3;
>>> -    if (byterange_mode) {
>>> -        hls->version = 4;
>>> -        sequence = 0;
>>> -    }
>>> -
>>> -    if (hls->flags & HLS_INDEPENDENT_SEGMENTS) {
>>> -        hls->version = 6;
>>> -    }
>>> 
>>> -    if (hls->segment_type == SEGMENT_TYPE_FMP4) {
>>> -        hls->version = 7;
>>> -    }
>>> +    if (last) {
>>> 
>>> -    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");
>>> +        if ((hls->flags & HLS_OMIT_ENDLIST==0)) {
>>> +            ff_hls_write_end_list(hls->m3u8_out);
>>> +        }
>>> 
>>> -    set_http_options(s, &options, hls);
>>> -    snprintf(temp_filename, sizeof(temp_filename), use_rename ? "%s.tmp" : "%s", vs->m3u8_name);
>>> -    if ((ret = hlsenc_io_open(s, &hls->m3u8_out, temp_filename, &options)) < 0)
>>> -        goto fail;
>>> +        if (vs->vtt_m3u8_name) {
>>> +            ff_hls_write_end_list(hls->sub_m3u8_out);
>>> +        }
>>> +    } else {
>>> 
>>> -    for (en = vs->segments; en; en = en->next) {
>>> -        if (target_duration <= en->duration)
>>> -            target_duration = lrint(en->duration);
>>> -    }
>>> +        byterange_mode = (hls->flags & HLS_SINGLE_FILE) || (hls->max_seg_size > 0);
>>> 
>>> -    vs->discontinuity_set = 0;
>>> -    ff_hls_write_playlist_header(hls->m3u8_out, hls->version, hls->allowcache,
>>> -                                 target_duration, sequence, hls->pl_type);
>>> +        en = vs->last_segment;
>>> +        if (en == NULL) {
>>> +            ret = 1;
>>> +            goto fail;
>>> +        }
>>> 
>>> -    if((hls->flags & HLS_DISCONT_START) && sequence==hls->start_sequence && vs->discontinuity_set==0 ){
>>> -        avio_printf(hls->m3u8_out, "#EXT-X-DISCONTINUITY\n");
>>> -        vs->discontinuity_set = 1;
>>> -    }
>>> -    if (vs->has_video && (hls->flags & HLS_INDEPENDENT_SEGMENTS)) {
>>> -        avio_printf(hls->m3u8_out, "#EXT-X-INDEPENDENT-SEGMENTS\n");
>>> -    }
>>> -    for (en = vs->segments; en; en = en->next) {
>>>        if ((hls->encrypt || hls->key_info_file) && (!key_uri || strcmp(en->key_uri, key_uri) ||
>>>                                    av_strcasecmp(en->iv_string, iv_string))) {
>>>            avio_printf(hls->m3u8_out, "#EXT-X-KEY:METHOD=AES-128,URI=\"%s\"", en->key_uri);
>>> @@ -1444,17 +1417,8 @@ static int hls_window(AVFormatContext *s, int last, VariantStream *vs)
>>>        if (ret < 0) {
>>>            av_log(s, AV_LOG_WARNING, "ff_hls_write_file_entry get error\n");
>>>        }
>>> -    }
>>> -
>>> -    if (last && (hls->flags & HLS_OMIT_ENDLIST)==0)
>>> -        ff_hls_write_end_list(hls->m3u8_out);
>>> 
>>> -    if( vs->vtt_m3u8_name ) {
>>> -        if ((ret = hlsenc_io_open(s, &hls->sub_m3u8_out, vs->vtt_m3u8_name, &options)) < 0)
>>> -            goto fail;
>>> -        ff_hls_write_playlist_header(hls->sub_m3u8_out, hls->version, hls->allowcache,
>>> -                                     target_duration, sequence, PLAYLIST_TYPE_NONE);
>>> -        for (en = vs->segments; en; en = en->next) {
>>> +        if( vs->vtt_m3u8_name ) {
>>>            ret = ff_hls_write_file_entry(hls->sub_m3u8_out, 0, byterange_mode,
>>>                                          en->duration, 0, en->size, en->pos,
>>>                                          vs->baseurl, en->sub_filename, NULL);
>>> @@ -1462,22 +1426,16 @@ static int hls_window(AVFormatContext *s, int last, VariantStream *vs)
>>>                av_log(s, AV_LOG_WARNING, "ff_hls_write_file_entry get error\n");
>>>            }
>>>        }
>>> -
>>> -        if (last)
>>> -            ff_hls_write_end_list(hls->sub_m3u8_out);
>>> -
>>>    }
>>> 
>>> 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 (ret >= 0 && hls->master_pl_name)
>>> -        if (create_master_playlist(s, vs) < 0)
>>> +    if (ret >= 0 && hls->master_pl_name) {
>>> +        if (create_master_playlist(s, vs) < 0) {
>>>            av_log(s, AV_LOG_WARNING, "Master playlist creation failed\n");
>>> +        }
>>> +    }
>>> 
>>>    return ret;
>>> }
>>> @@ -2078,6 +2036,11 @@ static int hls_write_header(AVFormatContext *s)
>>>    int ret, i, j;
>>>    AVDictionary *options = NULL;
>>>    VariantStream *vs = NULL;
>>> +    int target_duration = 0;
>>> +    int byterange_mode = 0;
>>> +
>>> +    target_duration = lrint(hls->time);
>>> +    byterange_mode = (hls->flags & HLS_SINGLE_FILE) || (hls->max_seg_size > 0);
>>> 
>>>    for (i = 0; i < hls->nb_varstreams; i++) {
>>>        vs = &hls->var_streams[i];
>>> @@ -2091,7 +2054,7 @@ static int hls_write_header(AVFormatContext *s)
>>>            goto fail;
>>>        }
>>>        av_dict_free(&options);
>>> -        //av_assert0(s->nb_streams == hls->avf->nb_streams);
>>> +
>>>        for (j = 0; j < vs->nb_streams; j++) {
>>>            AVStream *inner_st;
>>>            AVStream *outer_st = vs->streams[j];
>>> @@ -2130,6 +2093,47 @@ static int hls_write_header(AVFormatContext *s)
>>>            }
>>>        }
>>>    }
>>> +
>>> +    // write the header for the main hls playlist
>>> +    int64_t sequence = FFMAX(hls->start_sequence, vs->sequence - vs->nb_entries);
>>> +    hls->version = 3;
>>> +    if (byterange_mode) {
>>> +        hls->version = 4;
>>> +        sequence = 0;
>>> +    }
>>> +
>>> +    if (hls->flags & HLS_INDEPENDENT_SEGMENTS) {
>>> +        hls->version = 6;
>>> +    }
>>> +
>>> +    if (hls->segment_type == SEGMENT_TYPE_FMP4) {
>>> +        hls->version = 7;
>>> +    }
>>> +
>>> +    set_http_options(s, &options, hls);
>>> +    if ((ret = hlsenc_io_open(s, &hls->m3u8_out, vs->m3u8_name, &options)) < 0) {
>>> +        goto fail;
>>> +    }
>>> +
>>> +    vs->discontinuity_set = 0;
>>> +    ff_hls_write_playlist_header(hls->m3u8_out, hls->version, hls->allowcache, target_duration, sequence, hls->pl_type);
>>> +
>>> +    if((hls->flags & HLS_DISCONT_START) && sequence==hls->start_sequence && vs->discontinuity_set==0 ){
>>> +        avio_printf(hls->m3u8_out, "#EXT-X-DISCONTINUITY\n");
>>> +        vs->discontinuity_set = 1;
>>> +    }
>>> +    if (vs->has_video && (hls->flags & HLS_INDEPENDENT_SEGMENTS)) {
>>> +        avio_printf(hls->m3u8_out, "#EXT-X-INDEPENDENT-SEGMENTS\n");
>>> +    }
>>> +
>>> +    if( vs->vtt_m3u8_name ) {
>>> +        if ((ret = hlsenc_io_open(s, &hls->sub_m3u8_out, vs->vtt_m3u8_name, &options)) < 0) {
>>> +            goto fail;
>>> +        }
>>> +
>>> +        ff_hls_write_playlist_header(hls->sub_m3u8_out, hls->version, hls->allowcache, target_duration, sequence, PLAYLIST_TYPE_NONE);
>>> +    }
>>> +
>>> fail:
>>> 
>>>    return ret;
>>> @@ -2334,10 +2338,11 @@ static int hls_write_packet(AVFormatContext *s, AVPacket *pkt)
>>>            return ret;
>>>        }
>>> 
>>> -        if (!vs->fmp4_init_mode || byterange_mode)
>>> -            if ((ret = hls_window(s, 0, vs)) < 0) {
>>> +        if (!vs->fmp4_init_mode || byterange_mode) {
>>> +            if ((ret = hls_write_manifest_segment(s, 0, vs)) < 0) {
>>>                return ret;
>>>            }
>>> +        }
>>>    }
>>> 
>>>    vs->packets_written++;
>>> @@ -2421,7 +2426,7 @@ failed:
>>>        avformat_free_context(oc);
>>> 
>>>        vs->avf = NULL;
>>> -        hls_window(s, 1, vs);
>>> +        hls_write_manifest_segment(s, 1, vs);
>>> 
>>>        av_freep(&vs->fmp4_init_filename);
>>>        if (vtt_oc) {
>>> @@ -2447,6 +2452,9 @@ failed:
>>>        av_freep(&ccs->language);
>>>    }
>>> 
>>> +    hlsenc_io_close(s, &hls->m3u8_out, vs->m3u8_name);
>>> +    hlsenc_io_close(s, &hls->sub_m3u8_out, vs->vtt_m3u8_name);
>>> +
>>>    ff_format_io_close(s, &hls->m3u8_out);
>>>    ff_format_io_close(s, &hls->sub_m3u8_out);
>>>    av_freep(&hls->key_basename);
>>> @@ -2884,3 +2892,4 @@ AVOutputFormat ff_hls_muxer = {
>>>    .write_trailer  = hls_write_trailer,
>>>    .priv_class     = &hls_class,
>>> };
>>> +
>>> -- 
>>> 2.6.3
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 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


> 
>> I unfortunately don't know where to make this fix to make mpegts work better. Can you advise? I will submit fixes to this in a separate patch.
> 
> Or what about get the #EXT-X-TARGETDURATION position, to update it? looks like flvenc.c or movenc.c date shift
> 
>> 
>>> 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.

> 
> 
> Thanks
> Steven

Thanks
Steven







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