theeMule
12th March 2007, 06:54
So I've successfully reauthored an hd-dvd disc to blu ray, without reencoding the video. I'll post more detailed instructions when I have the chance.
Basically, I used EVODemux to demux the main movie EVO files. The demuxed VC1 stream I was able to import into Scenarist HDMV as is (it imports as 1080i 29.97fps, which is of course how HD-DVD discs are technically encoded)
(Note that commercial film-sourced bluray discs are encoded at 1080p-23.976fps)
Now for the audio I had a bit of trouble. In principle DD+ and TrueHD are supported by blu ray, but the implementations on the two formats are a little different. For DD+, the block structure of the stream is different due to differences between the program stream structure for hd-dvd and the transport stream structure for blu-ray. Also blu ray DD+ tracks contain a discrete plain dolby digital track interleaved with the DD+ stream. I believe the reblocking and interleaving is possible with the professional Dolby tools, but I don't have access to these.
For TrueHD, again, on blu-ray, a seperate plain ac3 track is interleaved, which is not the case on HD-DVD. Scenarist HDMV will build a truehd stream from an MLP stream plus an ac3 stream, but I do not know how to extract a standard MLP stream from the truehd stream on an hd-dvd disc.
For now, I ended up decoding the audio using the Sonic Audio decoder 4.2 and orbitlee's modified source filter, as well as the SoundOut plugin for avisynth. (Soundout->wav, then used wavewizard to split wav to 6 mono waves, then surcode dts to encode 1.5mbps dts which could be imported into scenarist hdmv)
In principle I would like to import the full decompressed 24bit 48khz lpcm track, but Scenarist will not import wav files larger than 4gb (since these have invalid headers by necessity).
So, to summarize, reauthoring is working with VC1 video (but in principle this should work for AVC or mpeg2 encoded hd-dvds as well, since Blu Rays video bitrates/formats are a superset of HD-dvd's I believe. Audio has to be reencoded for now, unless someone figures out how to reblock a DD+ stream and interleave regular DD, or how to extract a plain MLP stream from trueHD (The mlp could then be reencoded to ac3 to provide the ac3 stream for interleaving.)
Alternatively, if anyone knows how to decode the truehd stream, then we could simply put it on the blu ray disc as LPCM (assuming someone can figure out how to get >4gb lpcm tracks into scenarist HDMV)
One other issue I was considering. In principle the HD-DVD video streams, though flagged as 1080i-29.97 do contain the full 23.976 progressive sequence, for VC1 in particular. It would be very nice if this could be reflagged as 23.976p without reencoding, since it could avoid deinterlacing issues depending on the player.
Also of course we lose all the menus using this method, though in principle the menu assets could be demuxed as well and new menus built for the blu ray disc. (Perhaps once the two formats are better understood, someone will write a tool for automated conversion.)
As an aside, blu-ray (and I believe hd-dvd as well) can contain standard def mpeg2 FROM A DVD without reencoding. So it is also possible to reauthor standard dvd's to blu ray. (I'm thinking full tv seasons on one disc once dual layer BD-R's become more reasonable.)
Basically, I used EVODemux to demux the main movie EVO files. The demuxed VC1 stream I was able to import into Scenarist HDMV as is (it imports as 1080i 29.97fps, which is of course how HD-DVD discs are technically encoded)
(Note that commercial film-sourced bluray discs are encoded at 1080p-23.976fps)
Now for the audio I had a bit of trouble. In principle DD+ and TrueHD are supported by blu ray, but the implementations on the two formats are a little different. For DD+, the block structure of the stream is different due to differences between the program stream structure for hd-dvd and the transport stream structure for blu-ray. Also blu ray DD+ tracks contain a discrete plain dolby digital track interleaved with the DD+ stream. I believe the reblocking and interleaving is possible with the professional Dolby tools, but I don't have access to these.
For TrueHD, again, on blu-ray, a seperate plain ac3 track is interleaved, which is not the case on HD-DVD. Scenarist HDMV will build a truehd stream from an MLP stream plus an ac3 stream, but I do not know how to extract a standard MLP stream from the truehd stream on an hd-dvd disc.
For now, I ended up decoding the audio using the Sonic Audio decoder 4.2 and orbitlee's modified source filter, as well as the SoundOut plugin for avisynth. (Soundout->wav, then used wavewizard to split wav to 6 mono waves, then surcode dts to encode 1.5mbps dts which could be imported into scenarist hdmv)
In principle I would like to import the full decompressed 24bit 48khz lpcm track, but Scenarist will not import wav files larger than 4gb (since these have invalid headers by necessity).
So, to summarize, reauthoring is working with VC1 video (but in principle this should work for AVC or mpeg2 encoded hd-dvds as well, since Blu Rays video bitrates/formats are a superset of HD-dvd's I believe. Audio has to be reencoded for now, unless someone figures out how to reblock a DD+ stream and interleave regular DD, or how to extract a plain MLP stream from trueHD (The mlp could then be reencoded to ac3 to provide the ac3 stream for interleaving.)
Alternatively, if anyone knows how to decode the truehd stream, then we could simply put it on the blu ray disc as LPCM (assuming someone can figure out how to get >4gb lpcm tracks into scenarist HDMV)
One other issue I was considering. In principle the HD-DVD video streams, though flagged as 1080i-29.97 do contain the full 23.976 progressive sequence, for VC1 in particular. It would be very nice if this could be reflagged as 23.976p without reencoding, since it could avoid deinterlacing issues depending on the player.
Also of course we lose all the menus using this method, though in principle the menu assets could be demuxed as well and new menus built for the blu ray disc. (Perhaps once the two formats are better understood, someone will write a tool for automated conversion.)
As an aside, blu-ray (and I believe hd-dvd as well) can contain standard def mpeg2 FROM A DVD without reencoding. So it is also possible to reauthor standard dvd's to blu ray. (I'm thinking full tv seasons on one disc once dual layer BD-R's become more reasonable.)