HD-DVD and stuff

HD-DVD or 3x DVD are still not happening. There are just two software players - Cyberlink and DVD player in upcoming Leopard. Well, DVD player on Mac would only play DVD Studio created HD-DVD... I don't even know what to say about that... it wouldn't play most HD-DVD (apart from MPEG-2 encoded I guess). Cyberlink doesn't play HD-DVDs if it cannot find HDCP video card, so there is really no point in creating 3x DVD since nothing could play them even on the computer. $300 standalones would be out this Christmas shopping season, but next year they would be cheaper and computers would start to come out with HD-DVD drives and then I guess playback and authoring software would become available... Until then there is no point despite that I figured out how to make X264 encoded HD-DVD in DVD Studio.

There are two tricks:

• Like iPod DVD Studio cannot handle B-frames but unlike iPod could do CABAC. 4:3 SD material would be stretched to 16:9 so SD cannot be played back by standalone and thus SD material in AppleTV or whatever TV-appliance playback only. HD without B-frames... Hmm, 1280x720p@23.978 would require over 2Mbps, thus only about 3.5 hrs could be fitted on DVD (read even 2 movies might not fit)
• There gotta be a bug in mp4box because the only way to import is to remux raw h264 with ffmpeg. It gotta be raw track (will not work remuxing from mp4) and if audio is muxed too then video do not show up in DVD Studio (delete audio from mp4 and DVD Studio would see video)
• DVD Studio is very picky and doesn’t even like VRB .ac3 that comes inside ATSC streams – re-encoding with BeSweet fixes that. Surprisingly enough DVD Studio accepts AAC audio as well

Top it off with that it took DVD Studio over 2.5 hours to package 43 minutes worth of material and it is clear that DVD Studio is piece of junk. Additionally, I greatly doubt DVD Studio authored 3x DVD would be playable by standalones.

And DVD Studio is the only authoring software apart from Scenarist that could author H.264 HD-DVD. The rest are MPEG-2 only.

On HD encoding... Compressor is unbelievably slow – single pass ATSC transcode took 9 hrs for 43 minute show or 12.75xT or 0.07xRT on MacBook while on overclocked emachine it took 3.6xT or 2.5 hrs for the same show. Two pass encode with Compressor takes about twice as long as single pass, i.e. absolutely unreasonable 16-18xT or 12-15 hours and in fact is the only option since single pass Compressor encode doesn’t work – it encoded 2.0Mbps target to 250kbps, nice rate control algorithm and overall excellent job Apple!

On Bandwidth vs. Quality... 1.5Mbps single pass seems not to be enough but is almost OK for ATSC. At 2.0Mbps also not enough but better. 2.0Mbps would make a good compromise for ATSC. For DVD upconverts 2.0Mbps is also not enough even with 2-pass. Such high bitrates are because DVD Studio cannot import AVC with B-frames. With B-frame support 1.0-1.2Mbps is not enough for 2-pass, but it could be squeezed into 1.5Mbps I guess.

On Lenovo on SD upconverts mencoder did 5.4 fps/23.976 or 4.35xT or 2 hr movie would take ~ 9 hrs to transcode and that's on top of 25 minutes to run DGIndex. Compare that to 43+ fps/23fps or 1.8xRT +0.95xRT or 0.55xT+1.05xT=1.6xT for 640x362 encodes with Handbrake... and that's with b-frames and all. 2-pass encode with x264 took 22.7/7.46 or 1.3xT+3.2xT = 4.5xT on 1280x720@23.976 encode or the same as 4.35xT single pass with mencoder. For comparisson 1080i to 720p ATSC transcode took 9 fps/3.75fps or 3.33xT+7.99xT=11.32xT

HD bottomline is... 1280x720p@23.978 is the smallest and the most practical resolution for HD DVD. Since it takes ~5xT in the best case to transcode (from progressive material, deinterlacing would take twice as long), to be practical we still need to at least double processing power (Qxxx processor) to make it 2.5xT or about 5 hours to transcode your average movie (or twice as much for interlaced). Clearly that still would be too long and we need at least quadruple current processor speeds to get to reasonable 1.5xT or 2.5-3 hours as with Handbrake today. So $266 Q6600 on 1066 FSB wouldn’t quite cut it and from everything available today we need something along the lines of Mac Pro with two Xeon E5300 series or 8-cores in total for ridiculously huge amount of money (like $2500 that Apple wants for Mac Pro) or… I could spread encoding over several idling computers. This is not that hard actually. FreeNAS could push 50+Mbps over 100Mbps wire or ~7Mbps over 54Mbps WiFi – more than 5Mbps that any of my computers could take when encoding to H.264 or more than 10Mbps that Quad should take.

The scenario is

• capture to local drive and make VideoRedo output mpg to FreeNAS (could theoretically capture to FreeNAS, but MCE captures only to “Recorded TV” or local drives). This would take 44.78 fps/29.97=0.67xT. Run DGIndex 39/110=0.35xT or 1xT so far to prep the source not counting whatever it takes VideoRedo to find commercials.
• on FreeNAS create emachine.avs and lenovo.avs with trim(0,framecount()/2) and trim((framecount()/2) +1, 0) at the end respectively. (or even better use framenumbers from .vproj and transcode straight from .drv-ms) or slice by 6000 frames that takes 10 min for 1st and 26 min for 2nd passes on emachine transcoding from 1080i. Both emachine and Lenovo transcode 1080i at 3xT+7xT = 11xT; 720p at 2.72xT+4.28xT=7xT and SD upconvert at 1.3xT+3.2xT = 4.5xT
• Wait for mp4 to appear and then join them with copy /b a.h264 + b.h264 result.h264 and do the audio and muxing.

Source prep would take 1xT, so I won't be able to match Handbrake, but say we would try to match pure transcode without source prep. Both emachine and Lenovo transcode 1080i at 3xT+7xT = 11xT; 720p at 2.72xT+4.28xT=7xT and SD upconvert at 1.3xT+3.2xT = 4.5xT. So to make SD upconvert take 1.5xT we need an extra Core Duo for a total of 3 processors or 6 cores (4.5xT/3). To make it reasonable for 720p source we need to do 4.5x or 2 processors I have plus a Quad, but 1080i would still take 11xT/4.5~2.5xT and only running 2 existing computer plus Quad and Mac Mini would make it 11xT/6.5~1.7xT in addition to 1xT for source prep.

So 4 computers I want to have would do HD, but computers still need to double in power before it would be reasonable.