Tagged with compression - Personal View Talks https://personal-view.com/talks/discussions/tagged/compression/feed.rss Sat, 23 Nov 24 13:09:27 +0000 Tagged with compression - Personal View Talks en-CA Loudness Wars https://personal-view.com/talks/discussion/1847/loudness-wars Wed, 28 Dec 2011 03:47:49 +0000 Vitaliy_Kiselev 1847@/talks/discussions
http://www.soundonsound.com/sos/sep11/articles/loudness.htm (unfortunately full article is for subscribers only)
http://productionadvice.co.uk/loudness-war-dynamic-range/
http://productionadvice.co.uk/dynamic-range-day/
http://www.dr.loudness-war.info/

Other topic on PV - http://www.personal-view.com/talks/discussion/5036/very-good-site-about-loudness/p1]]>
VideoArtifact: Footage Quality Restoration Software https://personal-view.com/talks/discussion/16146/videoartifact-footage-quality-restoration-software Tue, 06 Dec 2016 22:19:34 +0000 rean 16146@/talks/discussions Video Artifact is a new standalone video editor for digital film restoration and footage quality enhancement.

It has free and paid editions.

http://www.videoartifact.com/va/

Program helps you to prepare footages from consumer or professional video cameras, digicams and V-DSLR.

It can remove MJPEG, MPEG, H.264, H.265 compression artifacts and digital noise, improves sharpness and color resolution up to 16 bit 4:4:4.

Restoration features:

  • Script-based to work with unique cases. You can use many filters in any combination.
  • 50+ specialized restoration filters work in Y, U, V separately in 8/16 bit.
  • Possibility to use dozens of different type denoisers for different noise type.
  • Accurate denoising that keeps micro details with no "plastic" effect.
  • Removing of sharping halos.
  • Linear color high quality spline-based resize to resize up to 4K. Resize halos can be removed.
  • Precise halo-free radius-dependent sharping.
  • Film grain emulation and 3D LUT grading.
  • 4:2:0 8 bit to 4:2:2/4:4:4 16 bit chroma reconstruction.

It can be used in a post-production workflow if you use V-DSLR or consumer cameras.
Currently 50+ camera models supported and hundreds of compatible models.

Special features:

  • Batch processing without GPU. Very fast: 5 fps for typical V-DSLR AVCHD source and 2 fps for 4K.
  • Automatic joining of MTS, MOV and MP4 spans and renaming to yyyymmdd_hhmmss.mov format.
  • Non-standard 16-255 to TV 16-235 levels conversion.
  • ITU-R BT.601 ↔ BT.709 floating point conversion.
  • NLE and DaVinci Resolve compatible workflow.
  • Mastering to webm VP9/Opus or mp4 H.264/AAC 1080p/720p/360p/240p.

Examples with various restoration methods are available at http://www.videoartifact.com/examples/

Some samples:

image image

image image

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Compressor during recording in Audacity https://personal-view.com/talks/discussion/14648/compressor-during-recording-in-audacity Wed, 24 Feb 2016 17:43:28 +0000 joethepro 14648@/talks/discussions Is it possible to apply compression while recording in Audacity, or is it only a post recording tool? This question applies to all filters, really.

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Adobe Audition compression for broadcast https://personal-view.com/talks/discussion/2251/adobe-audition-compression-for-broadcast Sun, 12 Feb 2012 04:33:43 +0000 kitano 2251@/talks/discussions Hi there,

Any recommendation on the workflow for broadcast. The sound source is a mono microphone.

At the moment I start by converting in stereo and then normalising it; I am struggling with the effects as which one to use for compression.

The sound I record is usually interviews in public places which sometimes has background noise. And on some occasions I record live street music.

I'd love to hear your views. ( I am a newbie with audition and sound engineering)

Thanks, Hakura

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Can high framerates offset compression artifacts? https://personal-view.com/talks/discussion/11507/can-high-framerates-offset-compression-artifacts Tue, 07 Oct 2014 11:24:11 +0000 Brian_Siano 11507@/talks/discussions I was looking at some footage I shot with a consumer-grade camcorder, of a running stream. I shot it at 60fps, so when I play it at a slow-motion 24fps it looks wonderful and fluid and alla that good stuff. However, when I freeze the frames, the narrow bitrate of the camcorder is pretty obvious-- the points where the water gets turbulent become chaotic little blocks of data.

So I have a question. If I shoot at 24fps, or 30fps, the compression artifacts are certainly visible. If I were to shoot at 60fps, and render it as 24 or 30-- not in slow-motion, maybe frame blending-- the renderer would have two frames to combine into one. Would this extra data enable me to reduce the compression blocking in the final?

Apologies if this is a stupid question.

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GH3 Data rate and colour management compression https://personal-view.com/talks/discussion/9174/gh3-data-rate-and-colour-management-compression Mon, 23 Dec 2013 06:05:35 +0000 Wotsisname 9174@/talks/discussions Hi all,

I am confused about the 50mbps / 72mbps date rate that the GH3 supposedly records at.

My footage, recorded as H264 MOV files in either of these high bit rates, is listed in FCP as between 5.8mbps and 8.5mbps. Analysing the footage with cinema tools reveals the same data rate - not the 50 / 72 it should be.

If I convert the files to ProRes I get the higher data rates - around 30 - 60mbps. Although this is closer, and sometimes in excess of the data rate I want, am I not merely up-resing the footage? The new date rate might be higher, but if it is not what the camera recorded, the information isn't t there.

I am also confused about the colour management. My h264 footage has a colour profile of 1-1-1. Is that the best I can get? I read somewhere that the GH3 will record 2-4-1. How do I set that?

Again up-resing to prores 422 or 444 will not introduce colours that are not recorded in the first place!

I look forward to hearing people's thoughts.

Jules

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Audio Compressors basics https://personal-view.com/talks/discussion/7229/audio-compressors-basics Wed, 12 Jun 2013 12:08:50 +0000 Vitaliy_Kiselev 7229@/talks/discussions

Compressors and limiters are specialized amplifiers used to reduce dynamic range — the span between the softest and loudest sounds. The use of compressors can make recordings and live mixes sound more polished by controlling maximum levels and maintaining higher average loudness. Additionally, many compressors — both hardware and software — will have a signature sound that can be used to inject wonderful coloration and tone into otherwise lifeless tracks. Compression can also be used to subtly massage a track to make it more natural sounding and intelligible without adding distortion, resulting in a song that's more “comfortable” to listen to. Alternately, over-compressing your music can really squeeze the life out of it. For those who are unfamiliar with compressors, having a good grasp of the basics will go a long way toward understanding how compression works, and confidently using it to your advantage.

Check full article at http://www.uaudio.com/blog/audio-compression-basics/

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Smoothest hack, intra, macroblocking... Noob questions ! https://personal-view.com/talks/discussion/7420/smoothest-hack-intra-macroblocking...-noob-questions- Wed, 03 Jul 2013 18:17:07 +0000 TruHype 7420@/talks/discussions Hello,

Attention, noob questions ahead !

I would like to know a few things : - Which is the smoothest hack on the GH2 ? (All the detail, no macro-blocking) - What does "Intra" or "AVC-Intraa" mean ? - What is Auto Quantitizer ? I'm not sure if a higher number means a better image (lower compression) or it's the inverse. What is better, AQ0 (all to motion), or AQ4 (all to details) ? - What does GOP stand for, and there is "Low-GOP", but then does that mean there's "high GOP" ? What are 12/15 GOP, 3 GOP and 6 GOP ? - What are P-frames, B-frames... ? - What is "Matrix" and "444 Matrix" ? - On some settings there's written "14-16 QP", or "QP16". What does QP mean ?

I've not seen much smooth looking GH2 videos on Youtube (unlike the canon videos), lots of them have a lot of macroblocking or whatever and causes the video not to be smooth, and sometimes there are some sort artifacts (I think it's because of the compression or something...). I'm a bit of a pixel-peeper :P Could someone explain me the causes of the un-smoothness, and why are some videos really clean compared to others ?

Example of smooth videos I've found :

(his videos are all smooth and clean)

PS : Can someone give me the link to download the 244mb/s hack ?

And here on EOSHD there's an article about Intra :

http://www.eoshd.com/content/4452/gh2-gets-avchd-intra-at-176mbit

But I still don't understand the difference between the 176mbit so-called "Intra" hack and any other one ! I'm confused...

Please answer !

Thank You.

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Hack Terms FAQ added to the Faqs section https://personal-view.com/talks/discussion/5893/hack-terms-faq-added-to-the-faqs-section Thu, 24 Jan 2013 13:28:15 +0000 Brian_Siano 5893@/talks/discussions Some of us have written an FAQ to explain, in general terms, what Vitaly's Hack actually does for the GH2. It's a basic summary of how the GH2 compresses its data, and why and how this impacts image quality.

This is the FAQ to read if you're trying to read the forums, and finding a lot of technical stuff and acronyms that are going right over your head. It won't make you design hacks as good as Driftwood's or Sanity or Cake, and it won't tell you which hack is the best one to use. But if you read it, you will understand what I-frames and P-frames are, what GOP is, what intraframing and interframing are, and a few other details that'll help you follow some of the discussions here.

http://www.personal-view.com/faqs/gh2-hack/hack-terms-faq

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GH2 hacked: Timeline Dropping footage in FCP7 log and transfer and compressor : SOS https://personal-view.com/talks/discussion/1655/gh2-hacked-timeline-dropping-footage-in-fcp7-log-and-transfer-and-compressor-sos Tue, 06 Dec 2011 15:15:54 +0000 Surfceo 1655@/talks/discussions I have researched for hours without finding a solution and hoping for guidance. I apologize if it has been addressed and I missed it.

Converting to Apple Pro Rez HD the Timeline is dropping the last section of clip in FCP 7 log and transfer and compressor. So a 30 second clip is transcoded to 20 seconds.

I can verify the full length of data is there watching teh AVCHD in preview but cannot get it to transcode fully. I am using a iMac 3.06, 4g ram and never had this issue prior to the hack.

I found a EOS Movie Plugin-E1 suggestion for transcoding but could not find any follow up on what the tag would be to modify the source file to recognize the GH2 and what the workflow would be in FCP to activate this plug-in.

http://personal-view.com/talks/discussion/615/log-and-transfer-old-problems/p1
http://www.finalcutuser.com/?p=1829


I have a project in the can I am desperate not to have to reshoot any help would be most appreciated.
………………………………………………………………..
1. Can anyone advise a workflow for converting Hacked GH2 AVCHD in FCP 7 or compressor to avoid this issue?
…………………………………………………..
2. I found someone is having success tried Volatic and lost even more footage….http://www.zeroplusplus.com/panasonic-gh2-42mbps-avchd-hack-panorama-stitching/
………………………………………………………………..
3. Even though the test file is only 30 seconds, would "not saving to an external HD" be the issue?
http://www.kenstone.net/discussions/read.php?3,36464,36464
……………………………………………………………
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JPEG estimator and quantization https://personal-view.com/talks/discussion/766/jpeg-estimator-and-quantization Thu, 25 Aug 2011 18:29:59 +0000 Vitaliy_Kiselev 766@/talks/discussions New interesting article about company

Q: How does the JPEG format works?

A: JPEG is a lossy compression, meaning that any JPEG compression involves some loss of information. The compression consists of several steps:

•Color space transformation from RGB to YCBCR
•Reducing the spatial resolution of the CB and CR components by a factor of 2 in the horizontal axis, or both in the horizontal and the vertical axis (this step is optional).
•Dividing each color components to blocks of 8×8 pixels.
•Transforming each 8×8 block to the frequency domain using a DCT transform.
•Quantization (reduction of precision by representation with a lower number of bits) of each of the frequency components using a quantization matrix. This is the main stage that causes loss of information.
•Entropy coding (a lossless compression, similar to ZIP) on the frequency components which have undergone quantization.

Q: Is saving an image in Photoshop in minimum JPEG compression (i.e. 12) lossless?

A: Even at quality 12, the Photoshop quantization matrix has values which are greater than 1, so the precision of some of the frequency components is reduced, meaning that some information is lost (you can view the quantization matrixes for Photoshop’s quality 12 here).

Actually, even when using a quantization matrix that has all values set to 1, there is a loss of quality due to the DCT transform and the conversion from floating point values to integer values.

Read the rest at: http://www.megapixel.co.il/english/archive/21907




Other interesting read on JPEGSnoop author page:

http://www.impulseadventure.com/photo/jpeg-quantization.html

http://www.impulseadventure.com/photo/jpeg-huffman-coding.html]]>