I am interested in using diffbind to perform differential expression analysis on some ATAC data. However, all I have is counts table for peaks (no beds or bams) and a meta table with the sample names and conditions they belong to. Is there a way to use diffbind from here and is there any benefit over simply using DESeq2 or edgeR?
You can import count data directly into DiffBind using the Counts column in the sample sheet. This is documented in the help page for dba.peakset(). It assume you have already generated a consensus peakset (same intervals for each sample) and counted the reads in each interval, so that you have a file or vector of counts for each sample.
The advantages of using DiffBind for this are mostly that you can use its reporting and plotting functions. The main limitation is that your experimental design need be pretty straightforward, otherwise you are better off using DESeq2 or edgeR.