splicing data of all ts fragment files cited in the hls sub index file to obtain multiple media files or for multiple hls sub index files corresponding to multiple profiles under the same hls primary index file splicing data of all ts fragment files cited in the hls sub index file to obtain one or more media files in an exemplary embodiment the operation that the modification device 20 modifies the hls sub index file further includes the following operation recording a path of the media file in which each cited ts fragment file lies into the modified hls sub index file in an exemplary embodiment the operation that the splicing device 10 splices data of ts fragment files cited in the hls sub index file includes that data of ts fragment files cited in the hls sub index file are sequentially spliced according to a play sequence of ts fragment files which is recorded in the hls sub index file or a splicing sequence which is additionally set in an exemplary embodiment after the splicing device 10 splices data of ts fragment files cited in the hls sub index file to obtain one or more media files the splicing device 10 is further configured to add an information field fields used for indicating a media file format in the media file files in an exemplary embodiment a name of the media file obtained by the splicing device 10 through splicing includes one or more pieces of the following information a type of the media file a profile to which ts fragment files contained in the media file belong and a code rate corresponding to the profile to which ts fragment files contained in the media file belong in an exemplary embodiment the.