<?xml version="1.0" encoding="UTF-8"?> <!-- This XML file describes the encryption applied to |bipbop-cenc*|. To generate the bipbop-cenc files, run the following commands: Encrypt bipbop-no-edts.mp4 with the keys specified in this file, and output to |bipbop-cenc-{video,audio}.mp4| MP4Box -crypt bipbop-frag-cenc.xml -rem 2 -out bipbop-cenc-video.mp4 bipbop-no-edts.mp4 MP4Box -crypt bipbop-frag-cenc.xml -rem 1 -out bipbop-cenc-audio.mp4 bipbop-no-edts.mp4 Fragment |bipbop-cenc-*.mp4| into 500ms segments: MP4Box -dash 500 -rap -segment-name bipbop-cenc-video -subsegs-per-sidx 5 bipbop-cenc-video.mp4 MP4Box -dash 500 -rap -segment-name bipbop-cenc-audio -subsegs-per-sidx 5 bipbop-cenc-audio.mp4 The above command will generate a set of fragments in |bipbop-cenc-{video,audio}*.m4s and |bipbop-cenc-{video,audio}init.mp4| containing just the init segment. To cut down the duration, we throw out all but the first 3 audio & 2 video segments: rm bipbop-cenc-audio{[^123],[123][^.]}.m4s rm bipbop-cenc-video{[^12],[12][^.]}.m4s MP4Box will also have generated some *.mpd files we don't need: rm bipbop-cenc-*.mpd Delete intermediate encrypted files: rm bipbop-cenc-{audio,video}.mp4 --> <GPACDRM type="CENC AES-CTR"> <DRMInfo type="pssh" version="1"> <!-- SystemID specified in https://dvcs.w3.org/hg/html-media/raw-file/tip/encrypted-media/cenc-format.html --> <BS ID128="1077efecc0b24d02ace33c1e52e2fb4b" /> <!-- Number of KeyIDs = 2 --> <BS bits="32" value="2" /> <!-- KeyID --> <BS ID128="0x7e571d037e571d037e571d037e571d03" /> <BS ID128="0x7e571d047e571d047e571d047e571d04" /> </DRMInfo> <CrypTrack trackID="1" isEncrypted="1" IV_size="16" saiSavedBox="senc" first_IV="0x00000000000000000000000000000000"> <key KID="0x7e571d037e571d037e571d037e571d03" value="0x7e5733337e5733337e5733337e573333" /> </CrypTrack> <CrypTrack trackID="2" isEncrypted="1" IV_size="16" saiSavedBox="senc" first_IV="0x00000000000000000000000000000000"> <key KID="0x7e571d047e571d047e571d047e571d04" value="0x7e5744447e5744447e5744447e574444" /> </CrypTrack> </GPACDRM>