[FFmpeg-devel] [PATCH] avformat/hlsenc: start_number new options

[Steven Liu]

2017-01-06 22:07 GMT+08:00 Bodecs Bela <bodecsb at vivanet.hu>:

> Dear All,
>
> in avformat/hlsenc the start_number option starts the playlist sequence
> number
> (#EXT-X-MEDIA-SEQUENCE) from the specified number. Unless hls_flags
> single_file is set, it also specifies starting sequence numbers of
> segment and subtitle filenames. Sometimes it is usefull to have unique
> starting numbers at each run, but currently it is only achiveable by
> setting this parameter manually.
> This patch enables to set start_number parameter automatically for
> practically unique numbers. If start_number is set to -1, then
> the start number will be the seconds since epoch (1970-01-01 00:00:00).
> If set to -2, then the start number will be based on the current
> date/time value as YYYYmmddHHMMSS. e.g. 20161231235659.
>
>
> thank you,
>
> Bela Bodecs
>
>
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>
>
Two question:
1. char b[21];   Why this is 21 ?
2. +    {"start_number",  "set first number in the sequence",
 OFFSET(start_sequence),AV_OPT_TYPE_INT64,  {.i64 = 0},     -2, INT64_MAX,
E},
Why is this -2 and the help message maybe need more infomation, for example
-2 mean -1 mean  0 mean, and default value.