I know this is old but I just finished a project like this. Please be aware that there are at least two types of Vimeo playlist init segments file types(extensions): .m4s and .mp4 . In your case above you also need to download the index_segment and concatenate that as well. If you dont have {pathsig}.mp4&r={hex}&range={#-#} you will probably have segment.m4s?pathsig={hex}&r={hex}&sid={#}&st={video|audio}. The concat process above if the same for both file types.