Is it possible to use alternate media (video) for packaging both a sign interpreted variant and a non sign interpreted variant in the same multivariant playlist? Is there a reference playlist implementation for this use case?
I was looking at techniques described in
Are you talking about two equivalent video versions - one with someone signing the audio?
If so, here's the simplest example I can think of - two video options, each with three bit rates and also trick play versions of same. The audio is multiplexed with the video to make the playlist simpler. You end up with a group-id for each video variant. Note the lack of URI for the "Plain" option - so that option is the same as the variant.
I'm not sure how well third-party players will handle this.
#EXTM3U
#EXT-X-MEDIA:TYPE=VIDEO,GROUP-ID="500kbs",NAME="WithSign",AUTOSELECT=YES,DEFAULT=NO,URI="Item/WithSign/500kbs-AV/prog_index.m3u8"
#EXT-X-MEDIA:TYPE=VIDEO,GROUP-ID="500kbs",NAME="Plain",AUTOSELECT=YES,DEFAULT=YES
#EXT-X-STREAM-INF:BANDWIDTH=750000,CODECS="mp4a.40.2, avc1.4d401e",VIDEO="500kbs"
Item/Plain/500kbs-AV/prog_index.m3u8
#EXT-X-MEDIA:TYPE=VIDEO,GROUP-ID="1Mbs",NAME="WithSign",AUTOSELECT=YES,DEFAULT=NO,URI="Item/WithSign/1Mbs-AV/prog_index.m3u8"
#EXT-X-MEDIA:TYPE=VIDEO,GROUP-ID="1Mbs",NAME="Plain",AUTOSELECT=YES,DEFAULT=YES
#EXT-X-STREAM-INF:BANDWIDTH=1339000,CODECS="mp4a.40.2, avc1.4d401e",VIDEO="1Mbs"
Item/Plain/1Mbs-AV/prog_index.m3u8
#EXT-X-MEDIA:TYPE=VIDEO,GROUP-ID="2Mbs",NAME="WithSign",AUTOSELECT=YES,DEFAULT=NO,URI="Item/WithSign/2Mbs-AV/prog_index.m3u8"
#EXT-X-MEDIA:TYPE=VIDEO,GROUP-ID="2Mbs",NAME="Plain",AUTOSELECT=YES,DEFAULT=YES
#EXT-X-STREAM-INF:BANDWIDTH=2417000,CODECS="mp4a.40.2, avc1.4d401e",VIDEO="2Mbs"
Item/Plain/2Mbs-AV/prog_index.m3u8
#EXT-X-MEDIA:TYPE=VIDEO,GROUP-ID="500kbsff",NAME="WithSign",AUTOSELECT=YES,DEFAULT=NO,URI="Item/WithSign/500kbs-AV/iframe_index.m3u8"
#EXT-X-MEDIA:TYPE=VIDEO,GROUP-ID="500kbsff",NAME="Plain",AUTOSELECT=YES,DEFAULT=YES
#EXT-X-I-FRAME-STREAM-INF:BANDWIDTH=94000,CODECS="avc1.4d401e",VIDEO="500kbsff",URI="Item/Plain/500kbs-AV/iframe_index.m3u8"
#EXT-X-MEDIA:TYPE=VIDEO,GROUP-ID="1Mbsff",NAME="WithSign",AUTOSELECT=YES,DEFAULT=NO,URI="Item/WithSign/1Mbs-AV/iframe_index.m3u8"
#EXT-X-MEDIA:TYPE=VIDEO,GROUP-ID="1Mbsff",NAME="Plain",AUTOSELECT=YES,DEFAULT=YES
#EXT-X-I-FRAME-STREAM-INF:BANDWIDTH=123000,CODECS="avc1.4d401e",VIDEO="1Mbsff",URI="Item/Plain/1Mbs-AV/iframe_index.m3u8"
#EXT-X-MEDIA:TYPE=VIDEO,GROUP-ID="2Mbsff",NAME="WithSign",AUTOSELECT=YES,DEFAULT=NO,URI="Item/WithSign/2Mbs-AV/iframe_index.m3u8"
#EXT-X-MEDIA:TYPE=VIDEO,GROUP-ID="2Mbsff",NAME="Plain",AUTOSELECT=YES,DEFAULT=YES
#EXT-X-I-FRAME-STREAM-INF:BANDWIDTH=186000,CODECS="avc1.4d401e",VIDEO="2Mbsff",URI="Item/Plain/2Mbs-AV/iframe_index.m3u8"