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

[Bodecs Bela]

2017.01.06. 17:33 keltezéssel, Steven Liu írta:
> 2017-01-07 0:22 GMT+08:00 Bodecs Bela <bodecsb at vivanet.hu>:
>
>>
>> 2017.01.06. 16:50 keltezéssel, Steven Liu írta:
>>
>>> 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
>>>>
>>>>
>>>> _______________________________________________
>>>> ffmpeg-devel mailing list
>>>> ffmpeg-devel at ffmpeg.org
>>>> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>>>>
>>>>
>>>> Two question:
>>> 1. char b[21];   Why this is 21 ?
>>>
>> you are right, 15 is enough.
>>
>>> 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.
>>>
>> yes, I have altered now but I have written verbosly into the doc
>> (muxers.texi), here:
>>
>> +If 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 as YYYYmmddHHMMSS. e.g. 20161231235759.
>> +Default value is 0.
>>
>> _______________________________________________
>>> ffmpeg-devel mailing list
>>> ffmpeg-devel at ffmpeg.org
>>> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>>>
>> I have enclosed a fixed version. A have changed some code, where greater
>> than 32 bit long sequence numbers were not handled correctly.
>> (av_get_frame_filename2)
>>
>> thank you.
>> Bela Bodecs
>>
>>
>> _______________________________________________
>> ffmpeg-devel mailing list
>> ffmpeg-devel at ffmpeg.org
>> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>>
>>
> +    {"start_number",  "set first number in the sequence, 0 is default, -1:
> second since epoch, -2: current datetime as YYYYMMDDhhmmss, actual value
> otherwise", OFFSET(start_sequence),AV_OPT_TYPE_INT64,  {.i64 = 0},     -2,
> INT64_MAX, E},
>
> I have check this option, i think add flag to control the start_number
> maybe better,
> for example:
> hls_flags
> hls_playlist_type
>
> maybe add a start_number_flags is better, What about you think?

Using hls_flags is not enough to specify different values for them.
I thought that there should be 3 options beside this start_number option.
hls_start_number_playlist, hls_start_number_segment and hls_start_number_vtt
Using start_number and any of the new 3 ones would be mutualy exlusive.

This way anybody could use the old option (start_number) and it won't 
break the current behaviour.
But those who want to have finer control, they may use the new options.

of course -start_number x  has the same effect as using
-hls_start_number_playlist x -hls_start_number_segment x 
-hls_start_number_vtt x


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