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November 22nd, 2007, 05:09 AM | #1 |
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Alternative to HDlink
Im trialing Prospect HD but at the moment having a lot of trouble with HDlink. I have a number of long mpeg HDV files which are 1080i 50i but HDlink always crashes when converting and splitting to High qual CFHD files.
I tried using a program like hdvsplit to split up the HDV files and then do it in small lots via HDlink but then I discovered that the avi files HDlink was spitting out were off in quality and had a slight greenish cast to them. Yet if I load up the same mpegHDV files into either Ppro or after effects and export to CFHD I get beautiful video. I have emailed support with my problem and links to sample files but in the meantime I was wondering if anyone uses something else to encode HDV files into CFHD? |
November 23rd, 2007, 05:04 AM | #2 |
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Amazing - so 50 views and no one can offer any help whatsoever - including cineform customer service who Ive emailed twice in the last 72hrs and am yet to receive even a 'we're looking into it'???
Ive done even more testing and the off/greenish encode happens on both the laptop AND my other PC and converting other codecs as well...even uncompressed AVI... Clearly its something to do with either how my systems are set up or some errant codec I have installed that may be interfering with HDlink...but its all moot unless I can get some support. At this point Im glad Im still trialing and haven’t shelled out $1,000 or Id be really annoyed... |
November 23rd, 2007, 07:17 AM | #3 | |
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We're using CF for long productions, so quality and quick bug fixes are important. Hope you can figure things out, as CF offers nice workflow and stunning final output. |
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November 23rd, 2007, 07:44 AM | #4 |
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Thanks Stephen,
That’s exactly it - I cant find a post or word anywhere on the web that sounds similar to my problem and I know CF is an amazing codec as if I use either Ppro or AE it encodes spot on. Its just HDlink, which is kind of the kicker as without it I have no way of getting my HDV mpegs into CFHD. Which is why I was wondering if anyone uses something else to batch encode into CFHD. Its got me stumped. |
November 23rd, 2007, 07:49 AM | #5 |
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Haven't tried it myself, but assuming HDV files are indeed basic MPEG2 files, VirtualDubMod should be able to take your files and encode them into CFHDs.
That said, your problem is puzzling as surely HDLink, PPro and AE are all using the same DirectShow components to both decode and indeed encode the video? That is, unless of course you are using basic AVI export on PPro and AE rather than the full-speed CineForm options.
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November 23rd, 2007, 10:39 AM | #6 |
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Sounds like two issues, one might not be a problem. In you first post you mentioned a crash on converting a large M2T, that shouldn't happen clearly, so the might something in the file itself causing an issue. So tried HDVSplit before converting, which doesn't modify the underlying MPEG2 data -- it is it not introducing a color shift, and I suppect HDLink is not either, rather you reference has a red shift. This is due to 601 vs 709 colorspace, yet so many tool default to 601 and screw up the color. The last time I tested this, Premiere native mode is still 601 -- so much for those thinking native gives them better quality. If you camera has color bars, record them and capture them native in Premiere and through HDLink, then check you scopes in Premiere, you should see that CineForm is correct.
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November 23rd, 2007, 09:11 PM | #7 |
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Thanks David,
Ok it is possible the crash has something to do with the mpeg file - maybe there is a time code break or something that is throwing HDLink? In any case Im going a bit crazy over this color issue - Ive converted a Gettys stock .mov file into CFHD via HDLink and also via TMPGenc Xpress. On my PC with a Dell 24" monitor I can see that the HDlink CFHD has a very slight greenish cast but also has a 1 pixel wide green line on the right. The original and CFHD from TMPG have none of this...however Ive exported jpegs which show this up on my PC Dell set up but I cant really tell on my laptop...so Im really confused. http://www.popfilms.com.au/01_Origin...cktime_PAL.jpg www.popfilms.com.au/02_CFHD_TMPEG_Xpress.jpg www.popfilms.com.au/03_CFHD_HDLINK.jpg Can anyone else look at the pictures and tell me if they can see any difference? And what is the green line on the right? Is it just a coincidence its green? |
November 23rd, 2007, 11:23 PM | #8 |
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Actually I have to point out that that weird green line only shows up in AE on CS3, not in the video file itself and not in AE CS2...
Maybe I should take up gardening... |
November 23rd, 2007, 11:50 PM | #9 |
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Start will camera bars. HDLink converts in the YUV space, no color conversion are occurring at all. Yet other source may be inject a color conversion if they use RGB to present their image. Although using SD sources for an HD optimized codec, will require you tell the decoder to use 601 not 709.
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November 24th, 2007, 04:38 AM | #10 | |
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All three have slightly different color variations, but the difference is slight. The top-left pixel reads in Photoshop as the following in terms of RGB values: Original: 225,223,198 TMPEG: 223,222,201 HDLink: 219,222,193 Bearing in mind that JPEG compression will play a part in negatively affecting readings like this (PNGs would have been better), that's not a massive amount of variance. To my eyes though the HDLink image looks closer - green line apart - to the original than the TMPEG one.
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November 25th, 2007, 03:24 AM | #11 |
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Thanks for the input - much appreciated.
Ok as I dont have the actual camera to do any color bar tests or re-capture straight via HDlink, I decided to do another test. I set up a very basic scene in 3DS Max and rendered out an 11 frame uncompressed AVI at 1920x1080. I then used HDlink to convert this into a 1080 CFHD avi and again used HDlink to downsize it to CFHD 720. As a test I used VirtualDub to do the same 1080 and 720 CFHD avi's . Following are the results - Both the vdub 1080 and downsized 720 are as close and clean to the original as can be. The HDlink files however show slight banding on the 1080 and worse banding / degradation on the 720. www.popfilms.com.au/HDlink_1080_AEresize.jpg www.popfilms.com.au/HDlink_720_converted.jpg www.popfilms.com.au/VDub_720_Lanc_res.jpg The above files are zoomed in at 200% to highlight the noise and banding. These are from an After effects 1280x720 comp with color management set to Rec 709 and all clips conform to Rec 709. Some other weirdness - the original uncompressed AVI file is 11 frames long, every other App see's that it is 11 frames long however HDlink outputs it as 10frames - so its dropping 1 frame? In terms of file size the HDlink 720 avi is 1,216KB whereas the VirtualDub 720 is 1,883KB. Sure the HDlink is dropping 1 frame but that wouldnt be enough to make up the difference leading me to believe that Vdub is encoding more information than HDlink is...yet its the same codec with, as far as I can tell, the same settings...? In any case from what I can see, vdub is doing a much better job of the CFHD codec than HDlink. I apologies in advance if its something Im doing to screw this up - I love the quality of the CFHD codec - just not from HDlink and certainly not using HDlink to resize anything. So is it me and something Im doing wrong or is HDlink not the best thing to use to convert into CFHD? |
November 25th, 2007, 06:42 AM | #12 |
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The VFW codec always produces larger file sizes at the same quality setting. This is because (I believe - I'm sure David Newman can correct me) the DirectShow encoder in HDLink uses a two-frame picture group whereas the VFW codec used in VirtualDub uses one. The difference in file size can be extraordinary depending on the content. If your 3DS scene is static that would explain the large difference as the second frame in the picture group would be identical to the first.
I can't really comment on your HDLink observations as I only used it myself for MOV rewrapping and now I don't use it at all as 8-bit CineForm AVIs work natively on Mac any way. One thing I do find intriguing though is that according to your test, VirtualDub is better at resizing than AE! These does make me happy (I'm very pro-open source) but on the other hand, all manner of CineForm loveliness should kick in using AE that you don't get using the VFW pipeline that VirtualDub does.
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November 25th, 2007, 08:42 AM | #13 |
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Hi Richard,
That may explain the file size difference, though it doesn’t explain the banding which given the 10bit arena shouldn’t be visible at all. Not to mention the noise / degradation HDlink seems to introduce when resizing. I dont think VD is better at resizing than AE - though I did use the Lanczoz3 setting, the banding on the HDlink 1080 AE resize was already present before I resized it in AE - I just used AE to make it 1280x720 so all images were the same size for comparison. Sorry if my naming scheme was misleading ;-) |
November 25th, 2007, 11:19 AM | #14 |
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HDlink is designed for YUV sources, i.e. 99% of all cameras. By using an RGB source you are introducing an 8-bit YUV colorspace conversion before an 8-bit scale. HDlink supports 10-bit YUV in 'v210' only from cameras. VirtualDub is also 8-bit only, but RGB, so it scaling is in RGB 444 space, before going into the codec. 8-bit RGB is internally converted to 10-bit YUV in the codec before compression (if you the 4:4:4 encoding option in our 2K products, it compresses at 12-bit), at 10bit you don't see banding -- why VirtualDub to CineForm looks nice for RGB sources (same goes for RGB sources on a Premiere timeline.) Again HDLink is designed for cameras where YUV to YUV doesn't introduce these issues. In AE, if you export using the Video for Window render module, you have lost the advantage of AE's deep pixel modes, as it is 8-bit only. Use the CineForm AVI export mode in trillions+ and 16-bit mode (required NEO HD/2K or Prospect HD/2K.) That should be very nice. Yes the AE scaler could be improved by Adobe.
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November 25th, 2007, 03:11 PM | #15 |
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See I knew there would be a logical explanation...just wish I understood what it all meant ;-)
No I think I get it...basically HDlink is for capturing from camera's whereas anything else either use something like Vdub or encode into CFHD directly from the application. Thanks for your patience David and everyone for their help. |
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