[FFmpeg-devel] [PATCH v3] ffmpeg: add option -isync

[Gyan Doshi]

On 2022-07-07 03:11 pm, Anton Khirnov wrote:
> Quoting Gyan Doshi (2022-07-04 18:29:12)
>> This is a per-file input option that adjusts an input's timestamps
>> with reference to another input, so that emitted packet timestamps
>> account for the difference between the start times of the two inputs.
>>
>> Typical use case is to sync two or more live inputs such as from capture
>> devices. Both the target and reference input source timestamps should be
>> based on the same clock source.
>>
>> If not all inputs have timestamps, the wallclock times at the time of
>> reception of inputs shall be used. FFmpeg must have been compiled with
>> thread support for this last case.
> I'm wondering if simply using the other input's InputFile.ts_offset
> wouldn't achieve the same effect with much less complexity.

That's what I initially did. But since the code can also use two other 
sources for start times (start_time_realtime, first_pkt_wallclock),
those intervals may not exactly match the difference between 
fmctx->start_times so I use a generic calculation.

Regards,
Gyan