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20th October 2020, 13:51 | #1 | Link |
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Convert VC-1 lossless?
Not sure if this is the right area but mentioned VC-1 so thought I'd give it a try.
I have some VC-1 content that I want to open in Premiere Pro but obviously can't. It's also in a M2TS container right now but know that could be changed but wouldn't help this specific situation. I don't care of size, but what would be the best way to take either the VC1 file directly or the M2TS container with the VC1 video and convert it lossless to another temporary format for editing in Premiere Pro? Thanks. JR |
20th October 2020, 15:45 | #2 | Link |
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I would convert to lossless AVC using x264 , with MP4 container (you can use --keyint 1 and --tune fastdecode for "snappier" editing but larger filesizes). It's the only lossless 8bit 4:2:0 codec that is truly lossless in Premiere. Other "lossless" codecs get converted to RGB when decoded. You can export lossless x264 again using the voukoder plugin, so full in/out is lossless . Premiere is one of the few NLE's that has a native YUV capable timeline and can work in 4:2:0 (it doesn't "force" 4:2:2 , or RGB conversion, unless you perform an operation or use a filter that requires it)
Run a few short tests first on the version you are using, because some point release versions of PP botched up lossless decoding. You can check with various methods, such as PSNR Do you really need "lossless"? ; x264 --qp 1 will be very nearly lossless and accepted by most NLE's, and treated as proper YUV (or studio level RGB in vegas) . At --qp 1, the quality will be significantly higher than even Cineform filmscan 3, or Prores 4444XQ . Usually ~8-16 higher dB PSNR. Usually qp 1 is overkill anyways Last edited by poisondeathray; 20th October 2020 at 16:05. |
20th October 2020, 17:59 | #3 | Link | |||
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VC-1 has some optional postprocessing modes for deblocking and deringing that can help if the content is visibly compressed. If you're using the built-in Windows decoder, the old WMV PowerToy can set the appropriate registry keys (the download isn't working at the moment, but zambelli says it'll be fixed today). Other workflows may or may not provide that option. (from a former Microsoft VC-1 evangelist) VC-1 was a lovely codec for the then use case of good quality with performant decoding on single core x86 processors without SSE2 (still plenty of Pentium III CPUs out there when WMV9 was released in 2002). Biggest flaws were the lack of adaptive quantization support in I-frames in the original Main Profile (fixed in Advanced Profile) and a too-weak in-loop deblocking filter (a perf tradeoff assuming most playback would use the optional postprocessing filters, which didn't actually get implemented much of anywhere outside of Windows itself; it wasn't even in Silverlight). |
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20th October 2020, 20:56 | #4 | Link | |
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On a PC and I don't think it's the filters that's the problem. Premiere in general will not process VC-1 based files in the app itself. Don't think it will use external filters or there wouldn't be so much complaining about it. |
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21st October 2020, 19:29 | #5 | Link |
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Premiere Pro definitely should be able to read VC-1 in a WMV file. I'm guessing it's the container that's the problem. Installing a DirectShow/MediaFoundation demuxer like LAVFilters may fix your problem.
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21st October 2020, 19:33 | #6 | Link |
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Yep, just opened a VC-1 Advanced Profile WMV file in Premiere Pro perfectly. I think it's even using GPU decode for it.
So, you can either remux the file to wmv/asf (I think ffmpeg can do this) or get a demuxer installed that Premiere Pro will use. I don't have any TS VC-1 handy to test to see if my LAVFilters works. |
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