[FFmpeg-devel] [PATCH] avformat/hlsenc: add option hls_out_list_size

[Bodecs Bela]

2018.04.10. 17:41 keltezéssel, Aman Gupta írta:
> On Tue, Apr 10, 2018 at 1:28 AM, Steven Liu <lq at chinaffmpeg.org> wrote:
>
>> when use hls_list_size and hls_flags delete_segments, there will saving
>> hls_list_size * 2 +- segments, so this option can control the segments
>> numbers.
>>
>> fix ticket: #7131
>>
>> Signed-off-by: Steven Liu <lq at chinaffmpeg.org>
>> ---
>>   doc/muxers.texi      |  4 ++++
>>   libavformat/hlsenc.c | 13 +++++++++++++
>>   2 files changed, 17 insertions(+)
>>
>> diff --git a/doc/muxers.texi b/doc/muxers.texi
>> index cb75c261c5..21ef786bcf 100644
>> --- a/doc/muxers.texi
>> +++ b/doc/muxers.texi
>> @@ -513,6 +513,10 @@ Segment will be cut on the next key frame after this
>> time has passed.
>>   Set the maximum number of playlist entries. If set to 0 the list file
>>   will contain all the segments. Default value is 5.
>>
>> + at item hls_out_list_size @var{size}
>> +Set the maximum number out of playlist entries. Default value is 1.
>> +This option should be used with @code{hls_flags delete_segments}.
>>
> I don't understand why a new option is required. Why can't the value of
> hls_list_size be re-used?
as I understand this is a totally different option:
nb_existing_segments = hls_list_size + hls_out_list_size
currently:
nb_existing_segments = hls_list_size + 1

I think this is a usefull new option. e.g. when network speed is very 
fluctuating and your client want to save all the segments.

>
>
>> +
>>   @item hls_ts_options @var{options_list}
>>   Set output format options using a :-separated list of key=value
>>   parameters. Values containing @code{:} special characters must be
>> diff --git a/libavformat/hlsenc.c b/libavformat/hlsenc.c
>> index 2a54b4342e..ff4c88d798 100644
>> --- a/libavformat/hlsenc.c
>> +++ b/libavformat/hlsenc.c
>> @@ -171,6 +171,7 @@ typedef struct HLSContext {
>>       float time;            // Set by a private option.
>>       float init_time;       // Set by a private option.
>>       int max_nb_segments;   // Set by a private option.
>> +    int hls_out_list_size; // Set by a private option.
>>   #if FF_API_HLS_WRAP
>>       int  wrap;             // Set by a private option.
>>   #endif
>> @@ -443,6 +444,7 @@ static int hls_delete_old_segments(AVFormatContext
>> *s, HLSContext *hls,
>>       HLSSegment *segment, *previous_segment = NULL;
>>       float playlist_duration = 0.0f;
>>       int ret = 0, path_size, sub_path_size;
>> +    int segment_cnt = 0;
>>       char *dirname = NULL, *p, *sub_path;
>>       char *path = NULL;
>>       AVDictionary *options = NULL;
>> @@ -456,14 +458,24 @@ static int hls_delete_old_segments(AVFormatContext
>> *s, HLSContext *hls,
>>       }
>>
>>       segment = vs->old_segments;
>> +    segment_cnt = 0;
>>       while (segment) {
>>           playlist_duration -= segment->duration;
>>           previous_segment = segment;
>>           segment = previous_segment->next;
>> +        segment_cnt++;
>>           if (playlist_duration <= -previous_segment->duration) {
>>               previous_segment->next = NULL;
>>               break;
>>           }
>> +
>> +        if (!hls->hls_out_list_size) {
>> +            av_log(s, AV_LOG_WARNING, "the hls_out_list_size value is 0,
>> that's wrong, so turn it to default value 1.\n");
>>
> If 0 is invalid value, it should be disallowed instead of showing a warning.
>
>
>> +        }
>> +        if (segment_cnt >= hls->hls_out_list_size) {
>> +            previous_segment->next = NULL;
>> +            break;
>> +        }
>>       }
>>
>>       if (segment && !hls->use_localtime_mkdir) {
>> @@ -2779,6 +2791,7 @@ static const AVOption options[] = {
>>       {"hls_time",      "set segment length in seconds",
>>   OFFSET(time),    AV_OPT_TYPE_FLOAT,  {.dbl = 2},     0, FLT_MAX, E},
>>       {"hls_init_time", "set segment length in seconds at init list",
>>       OFFSET(init_time),    AV_OPT_TYPE_FLOAT,  {.dbl = 0},     0, FLT_MAX,
>> E},
>>       {"hls_list_size", "set maximum number of playlist entries",
>> OFFSET(max_nb_segments),    AV_OPT_TYPE_INT,    {.i64 = 5},     0, INT_MAX,
>> E},
>> +    {"hls_out_list_size", "set maximum number of out to playlist
>> entries",  OFFSET(hls_out_list_size),    AV_OPT_TYPE_INT,    {.i64 = 1},
>>   0, INT_MAX, E},
>>
> I think you can change this to 1, INT_MAX to disallow 0 values.
>
>
>>       {"hls_ts_options","set hls mpegts list of options for the container
>> format used for hls", OFFSET(format_options_str), AV_OPT_TYPE_STRING, {.str
>> = NULL},  0, 0,    E},
>>       {"hls_vtt_options","set hls vtt list of options for the container
>> format used for hls", OFFSET(vtt_format_options_str), AV_OPT_TYPE_STRING,
>> {.str = NULL},  0, 0,    E},
>>   #if FF_API_HLS_WRAP
>> --
>> 2.15.1
>>
>>
>>
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