format_ctx = avformat_open_input_unique(&FFmpegCapture::read_srt_thunk, this,
mpegts_fmt, /*options=*/nullptr,
AVIOInterruptCB{ &FFmpegCapture::interrupt_cb_thunk, this });
format_ctx = avformat_open_input_unique(&FFmpegCapture::read_srt_thunk, this,
mpegts_fmt, /*options=*/nullptr,
AVIOInterruptCB{ &FFmpegCapture::interrupt_cb_thunk, this });