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Dear Dan and Luben,
I used to have the trial version of PluralEyes that expired now, but can tell you I am usually able to synchronize manually (using waveforms) as precisely as PluralEyes can - yet in the case of EX1 35 Mbps (native) vs. nanoFlash 35 Mbps, this i s still impossible...It's close, but still the frame match is not quite spot on. Dan, I wonder: how many frames long is the nanoFlash GoP in case of PAL (or 50 Hz Area) files, like my 1080/25p? It should be 12 frames (vs. 15 frames for NTSC) - but perhaps it isn't? If CD doesn't differentiate between PAL and NTSC GoP length, this could be one reason for the lack of frame synchronization with the EX1 native clips. Also interesting would be to know what the number of B frames is, how the mpg2 non-linear quantization is performed, etc, etc... BTW, it's a pity that a common utilities like MediaInfo cannot display all the CD codec info (it only displays bitrate of the video stream). No other data of the video stream can be read; MediaInfo doesn't recognize the audio streams, either. |
Now I'm getting worried, not about the noise but why you cannot align frames.
Surely you can just line two clips up using the source timecode? |
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I just tried the Multicamera tools in Vegas and managed to perfectly align a native EX1 clip with the simultaneously recorded, 35 Mbps nano clip, using "Lay out tracks using media timecode". So, provided nanoFlash is using embedded timecode from the camera's SDI, it IS possible - at least with both clips being the same bit rate. PS. It's also possible with different bitrates - so, looks like we have this problem (which branched off a little OT in this "noise thread") solved. I was so focused on the noise issue that I never thought of this obvious method of alignment. Probably also due to the fact that in my multi-EX1 projects so far, I never relied on this tool in Vegas as the timecode tended to be a little off between the individual cameras, making it a must to manually synchronize using sound waveforms... Thanks, Bob! |
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OK, I have revised my test material, and think I owe you all some very important update/conclusion.
Thanks to: a) Rafael and Dan, who pointed out the importance of comparing I-frames for any conclusion about the noise to be valid, b) Bob, who reminded me how to properly align two clips with frame accuracy, using internal timecode (shame on me !!!), - I can more precisely conclude now that: 1. With the "shimmering" nature of the chroma noise (whose intensity and form changes from frame to frame in any Long-GoP file), some of my previous comparisons were invalid in that they didn't compare the same, precisely aligned frames of the EX1-native vs. nanoFlash clips. After having them aligned properly using internal TC (thanks Bob again), the highest bitrate nanoclips (like those at 180 Mbps) do show considerable chroma noise, but I'm now more prone to say - with a high level of certainty - that it's not so much the nanoFlash augmenting chroma noise, but the EX1's native codec hiding it (along with detail), due to its much coarser compression which smooths out the picture 2. Properly aligned comparison of the nanoFlash high bitrate L-GoP frames vs. EX1-native frames, does NOT show more chroma noise increase than I-Frame Only clips comparison with EX1-native frames - unlike I wrongly concluded earlier. 3. While apologizing for even more ugly pictures, I'm attaching one more pair of blown-up frames - this time, the EX1 native (left) vs. nanoFlash I-Fo at 220 Mbps. While the higher level of chroma noise in the latter is evident, so is the much lesser macroblocking - especially around the high-contrast shadow patches on the roof, or around the metal nail heads in the level board. |
Dear Piotr,
I will look into the 12 versus 15 GOP question you raise. In reference to "MediaInfo": We have to label certain of our higher bit-rates as 50 Mbps, otherwise many NLE's would not recognise our files. Of course, you get the actual benefit of the bit-rate you choose. I do not know why the audio info does not show up in MediaInfo". |
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Dear Dan,
Actually, the newest MediaInfo version DOES recognize and display the bitrate correctly. It doesn't report other details (like the GoP structure and length), or any audio info at all - please see attached screen for a nanoFlash 180 Mbps L-GoP clip. |
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The problem is not to match the SxS picture with the Nano picture. The problem is that the same frame in both devices are not necessarily the same kind of frame (I, B,P). The camera processor and the Nano start to record in different moments. The GOPs are not the same in both devices. What is an I frame in the SxS file, may be a P or B frame in the Nano file. rafael |
Okay, I just want to say that this thread really shows how wonderful the nano is, and how excellent the guys at CD are. They patiently answered the ?'s posed here and came up w/ meaningful suggestions and good explanations.
And Piotr, thanks for all the images. This may have been a little bit of a chase down a rabbit hole, but I know I learned a lot reading through this. Thanks again everyone and for letting me stick my nose into this. As much as the middle of this thread got a little muddy, the last two frames posted by Piotr are ringing endorsement for the nano. |
Wow,
Those last two posted pictures form Piotr really are a huge endorsement for the nanoFlash. Even though I think the picture from the EX is one of the best for any sub $10K camera out there. But add in the nanoFlash and you end up with one incredible system. Very much worth the extra money and time of setting up equipment. Garrett |
I'm pleased everything in the garden is now rosy. I spent the weekend testing out my just arrived nanoflash and am very satisfied with the results to say the least.
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I fully understand your point - there are ways in Vegas to place the cursor on the I-frame exactly. The problem had been that I couldn't find a cursor position that would be at the corresponding I-frames for BOTH clips; once synchronized though, the frame comparison is now fair. And the results are as I described above - predictable. In both nanoFlash formats, there is more detail and more noise than in the native EX1 clip; the higher the bitrate used, the more visible the noise. Being aware of this, one must just decide on his optimum settings (of the scene, camera settings, and nanoFlash bit rate) which may vary depending on the intended destination of the video, CF/HDD storage space available, delivery format, extent of post-processing, using or not color correction in post, using or not noise reduction in post, etc. There is just one issue left that still requires shedding some more light at, and I'm counting on some technical suggestions from Dan: the whip pan example, where the movement blur was evidently accompanied with not just excessive noise, but also heavy pixelation of the nanoFlash frame. I'd like to thank everyone participating in this little "investigation" of mine for their friendly advice, and their patience with me :) Piotr |
Dear Piotr,
I do not like to speak beyond my level of expertise and I like to defer to others when evaluating images. (I actually learn quite a lot by reading the posts of true experts.) This, of course, does not mean that I do not have an opinion. I will offer my analysis of the two images in Post 103, but only since you have specifically requested it. You were doing a whip pan, according to another post in this thread. When you record at 35 Mbps 4:2:0 in the nanoFlash or Sony EX camera you will see less detail, the image will have a smoothing effect. With a fast whip pan, you can present more detail than the 35 Mbps can handle, thus it can appear smooth. With a 100 Mbps codec, the signal presented by the camera will be recorded more accurately. (This is not just marketing speak, this is based on a very thorough analysis by Mr. Richard Wolnowski who tested our 100 Mbps codec for 6-weeks, throwing excessive detail and excessive motion to the Flash XDR. Richard's testing was with the Thomson Viper and not the Sony EX, but the principle stays the same.) In Post 103, I do not see pixelation, but this is one of the reasons that I do not like to analyze images. Others may call it pixelation, and they may be 100% correct. Also, I do not know how this image plays back at normal speeds. I assume that this was shot at very low light levels; you have provided much of the camera detail about this shot in a previous post. May I suggest that you try some whip pans, if you are going to include them in your work, under more normal lighting conditions. Also, since I do not present myself as an expert at image analysis, I welcome others to join in, in analyzing the images in Post 103. I hope this helps. |
Dear Dan,
Thanks for the clarification of your standpoint on this. Like you, I'm inviting everyone to discuss this issue. Myself, I'll repeat the "whip pan" experiment in a more controllable fashion. In the meantime, however, I'd like to draw you attention to, and ask your opinion on, the following observation that is a little off-topic in this thread, but has surfaced as a side-result of my investigation described herein. As I mentioned in previous posts, I did have some difficulties in perfectly aligning simultaneously recorded clips from the EX1 and the nanoFlash. The method I've always used before with EX1 clips was based on the audio waveforms, and it doesn't work when one of the clip is a native EX1 clip, and the other comes from the nanoFlash: after aligning the waveforms precisely, the picture frames are slightly off. At some point, Bob grant has reminded me about the obvious method based on the clips' internal timecode; using it it's now possible to align the video frames perfectly, but I'm seeing the following now: 1. The nanoFlash clip offset is some 9 frames, i.e. after precise video alignment, the nano-recorded clip starts 9 frames later in time than the EX1 "original". Some SDI latency is normal, I suppose. 2. What surprises me though is that with such a perfect picture frame alignment, the nanoFlash-recorded audio is further offset by an additional 1 frame (so the total audio offset between the nano clip and the EX1 original is some 10 frames). It would also explain why I couldn't get frame-accurate video alignment when using the audio waveforms! The above numbers I can see with a 100 Mbps, Long-GoP clip. I haven't checked whether the offsets are the same with other formats/bitrates. Could you please shed some light on it? Piotr |
Dear Piotr,
I am assuming that you are triggering the nanoFlash on Incrementing Timecode. Yes, there is a slight delay in recording, a few frames. Of course, if these few frames are important, then you could use our pre-record buffer. Generally, I recommend against using the pre-record buffer unless there is an actual need for it. It is easier to edit, in my opinion, if the extra seconds at the beginning of each take (the pre-recod buffer footage) is not there. Is you nanoFlash in an idle mode (not playing back) when you trigger the camera to record? If you nanoFlash is playing back, it takes longer to switch the nanoFlash (actually the Sony Codec), into record mode. We have to switch the Sony Codec from Playback Mode to Record Mode. What firmware version are you using? This has significance in your audio/video sync issue. |
Dear Dan,
Of your questions, the only one relevant to the audio/video delay difference is the firmware version I'm using - and this is the current 1.5.126. I don't care about the overall delay - as I said, this seems normal to me. Thanks, Piotr |
Piotr,
Are you saying that the TC is 9/10 frames off in clips recorded on SxS and NF. When NF is set to use TC from the EX? I know that the NF lags in starting up, but the TC for the individual frames match in my setup. I will recheck to make sure, if this is what you mean. |
Dear Olaf,
I believe that Piotr is saying that the file started 9 frames after the SxS file started. The timecode on the frames will match exactly, as you have reported. Piotr also said that the audio is one frame off, with firmware 1.5.126 under his test conditions. |
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Olof,
Let us clarify: after TC alignment in Vegas, both clips' video is perfectly synchronized with a single frame precision and TC matched exactly. BUT: I just aligned other 2 clips by TC, and now the nanoFlash clip (100/L-GoP) starts 23 frames later than its EX1 "original", and its audio is still 1 frame behind (i.e. lags by 24 frames behind the original - take a close look a the waveform peaks, e.g. right to where I placed the cursor). |
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Should we start another thread on this? This one is already very long, and complicated enough :) |
Dear Piotr,
Just as a camera with a tape deck, it takes time to start recording. Your EX camera may also take time to start recording. I do not know if this is true or not, but you could test it by recording a clock with a sweep second hand. When starting the nanoFlash via incrementing timecode, it takes us time to start recording. It does appear, that in 1.5.126, the audio is off by one frame. It is not appropriate to say that we our audio is out of sync by 24 frames. |
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Dear Piotr,
I am assuming that you meant to say "Frames" and not "Seconds". I do not think that your nanoFlash is experiencing difficulties. We put great effort into attempting to achieve perfect Audio/Video sync. Surprising as it may seem, we have to ensure that it is right, for every mode/option, for every release that we build. Based on your comments, it appears that we are off by one frame for your specific conditions. We will work on this. You are using 1.5.126. Our latest firmware that we sent out, a Public Beta, is 1.5.249. We will be releasing new firmware soon. It will be 1.6.xxx. |
Dear Dan,
Sure thing - I meant frames, not seconds (correcting now). Thanks for the information Piotr |
Dear Piotr,
In our upcoming release, and (I believe) in the Public Beta 1.5.249, you will find that the delay before we start record has been drasticly reduced. Also, the Audio/Video sync has been improved in our latest releases. Our latest release 1.6.6 is in test. We will release it as soon was we finish testing it. |
Thanks Dan! That's great. A question to you please. My NF some how did slowdown after I upgraded to the new beta firmware. The slowdown is quite visible when booting and going through the menu. Going back to the Production firmware does not fix that problem. I am sure that this has happened.
Would you please comment on this. Thank you Luben |
Dear Dan,
Thanks for the information. I must admit that - having spent almost 2 months to make the previous Beta work with my specific CF cards - I didn't even load the current public Beta at all, after learning the Record Indicator doesn't work as expected :) But of course I'm eagerly looking forward to the 1.6.6 version. By saying "the delay before we start record has been drastically reduced", you got me very interested to know: - is the delay constant now? The reason I'm asking this is that - as you have probably noticed - with the current firmware I've been getting delays varying considerably (like 9 - 23 frames); is it going to be more consistent now? Of course, we're still talking "Incrementing TC" trigger mode.... Thanks and Regards, Piotr |
Dear Piotr,
There are three main components in the nanoFlash. 1. The Sony Module, which performs the codec work, compression and decompression. 2. The FPGA (Field Programmable Gate Array). This is an extremely fast device and does almost all of the work in the nanoFlash. 3. The Microprocessor. This is a relatively slow device, which does housekeeping, other tasks, and the human interface. Previously, the Microprocessor was used to setup the nanoFlash for recording. Now, the FPGA performs this task and it is much faster. When the new release comes out, I suggest that you run your own tests, but I feel that it will be very consistent. |
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Thanks! Piotr |
Dear Piotr,
Yes, this is a serious improvement. |
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Dear Dan,
I posted a question for you here and in Beta Firmware Thread. Would you please care to comment on it here or there please. Thank you |
Dear Luben,
I just posted an answer for you in the other thread. http://www.dvinfo.net/forum/converge...1-5-249-a.html |
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Just to get back on topic here...
Previously, I have posted a comparison of EX1 native vs. nanoFlash I-Fo/220. It showed the compromise one is making when using the 220 Mbps, I-frame only mode - *some* increase of noise, but at the same time *considerable* decrease of the mosquito noise when compared to the corresponding EX1 native picture... Well, to show a similar comparison on the other extremum - the nanoFlash Long-GoP, 50 Mbps/4:2:2 vs. the native EX1, 35/4:2:0 images - I'm posting the 2 grabs below. One can clearly see that while the noise is *not* increased, the detail definition (see the roof, and the foliage) is much better in the nanoFlash picture - in spite of its bitrate being just 50 Mbps! Heck - the improvement in the lower-left roof detail is even visible in the attached thumbnail view! |
Dear Piotr,
The nanoFlash image is labeled 35 Mbps. Is this correct, or is this a 50 Mbps image as you described in your post? |
Yes indeed - my mistake, sorry. It IS 50 Mbps - I'll try to correct this...
PS. The label's now correct. |
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I couldn't resist - here is another comparison, again between the EX1 native and the nanoFlash L-GoP, 180 Mbps. This time however, these are full frames - not blown-up crops. Just notice the much better edge definition of the red flower that the 180 Mbps nano clip is giving thanks to the 4:2:2 color resolution...
Scenes like this do not contain large, uniform color, shaded areas that could introduce noise - this is where the nanoFlash really shines! I guess this posts nicely rounds up this thread, as it goes back to the "35/4:2:0 vs. 180/4:2:2" subject... |
...am I being paranoid?
I've been testing my EX1/nanoFlash even more, trying to find a combination of settings to both that would minimize the noise - and thinking...
So far, the only post (in this thread or in the one at EX forum: http://www.dvinfo.net/forum/sony-xdc...ctive-ex1.html) that agrees with my observation fully, and doesn't indicate I'm splitting hairs, or using improper comparison methods (like posting jpeg's instead of png's), has been the one by Voitto (http://www.dvinfo.net/forum/sony-xdc...ml#post1539612). I've been wondering: Is the reason for people not confirming the problem, that they don't want to admit it exists? You know, having spent a lot of cash on an EX1/3 camera, in some cases also on the nanoFlash - it can be sort of difficult to admit openly it doesn't perform as hoped, and expected basing on the nice 54dB S/N figure in the specs... I could understand such reluctance, but I'd once again ask those knowledgeable EX users to step out and say openly what they think on the subject that's bugging me, like: - either: yes, the noise is there, and in some cases - especially with high bitrates nanoFlash recordings - it can make the footage unusable without de-noising in post (which in my opinion, can negate the very sense of using high nanoFlash bitrates in the first place) - or: no, I do not find my EX camera recording particularly noisy (and the higher nanoFlash bitrate I'm using, the better results I'm getting)... Some feedback like this would help me tremendously - at the current state of affairs, I almost start to feel paranoid... Is my camera noisier than others, and should it be sent in for servicing? Or maybe my SDI cable is to blame? 'Cause you see, the only other explanation of seeing things other people do not see is that I'm editing my stuff using a large, 50" plasma display, hung above my desktop monitor, and watched from 1-1.5m. This way, I'm really seeing individual pixels, and can tell noisy picture from a clean one. But, isn't using large displays what HD is about? |
Piotr, I am very happy with my Nano purchase. I moved from Sony Z1U to EX1 and was pleased but not satisfied until the Nano. I see a large quality increase in real detail and a substantial reduction if not elimination of macroblocking artifacts for handheld operation. The noise increase you describe is seen in my footage, but I am not as worried about noise as you are. I would prefer to record my scene and camera noise as accurately as possible so that future noise reduction technology operates on the mildly-compressed Nano files.
Have you tried the economical NeatVideo noise reduction plug-in for Sony Vegas? I will try that. Neat Video :: filtration examples |
Hi Gints; thanks for the response.
I have just used the (free) Dynamic Noise Reduction filter from Mike Crash on a particularly noisy, 100 Mbps L-GoP nano file, and the results are promising. People at the SCS forum say the Neat Video plugin is even better - I will definitely be purchasing it soon... |
Dear Piotr,
Here are a few thoughts and questions that I have: 1. Are you doing everything possible to minimize the noise at the camera? For example, are you using zero (or lower gain)? Are the scenes properly lit? Many, but not all of your examples are zoomed in, portions of images, in the deep shadows. Are the controls in the camera set to minimize noise or to accentuate it? 2. When you record, using the nanoFlash at very high bit-rates, I strongly feel that we can faithfully capture the images that are provided to us. If you can test your camera's output with a professional monitor you will be able to see if the camera has excessive noise or not. 3. Consumer televisions, even large screen plasma televisions, can have noise. Personally, I have been testing some 23" to 25" LCD televisions, major brands, I was amazed at the high level of noise. When I play the same footage on my professional 24" Sony LMD-2450wHD monitor, there is no visible noise. 4. Viewing a 50" Plasma at 1 to 1.5 m is certainly not the recommended, nor typical, viewing distance. How is your signal getting to your Plasma, is it via HDMI, Component, or via a computer signal via a DB-15 or other connector? 5. Do you see noise, when using zero gain, in a well lit scene, playing at normal video speeds? 6. As far as the 54 dB noise figure, I am assuming you are referring to the camera specs. This value was probably achieved using far more light than the shadow details that you have been posting. 7. We have tested the nanoFlash, end to end, with a very nice Video Clarity system. The results are posted on our website, near the bottom of this page. These tests eliminate the camera variables and test the quality of the recording/playback. Quality | nanoFlash | Video Recorders and Converters |
Dear Dan,
Thank you for the response to my doubts - not the first one in this thread :) I'd like to assure you that - with my experiments (however unscientific they may be) - I have practically eliminated the "my nanoFlash being defective" unknown from the equation. The EX cameras definitely DO generate excessive noise (some people confirmed it for me in http://www.dvinfo.net/forum/sony-xdc...ctive-ex1.html "parallel" thread of mine at the EX forum). And to answer your question: yes, it can be noisy even in well exposed scenes, and gain at -3 db - this is what worries me most. The nanoFlash merely makes it more visible (along with better details), when you compare its high bitrate picture with the native, 35 Mbps/4:2:0, EX1 compression. What I'm trying now to achieve through my experiments is find the best combination of the on-camera settings (influencing noise), and the optimum nano format (particularly bitrate), to use in specific situations. I'm also considering using de-noising filters in post, but somehow I still tend to think of it as the last resort... Not sure yet whether or not I will include de-noising in my post arsenal on a permanent basis. As to the monitoring equipment I'm using, and the way I use it - well, I agree a consumer plasma is only what it is - far from the professional stuff. But I can assure you that when I manage to produce a near-perfect piece of image, it can look properly (i.e. perfect) even on the device I'm using - and from such a close distance, too. And last but not least, a word on the examples I posted here: as you have noticed, I always illustrated my point with a pair of screen grabs from my NLE - one always being the native EX1, the other from my nanoFlash. Thus - even wiith a somewhat extreme examples, like blown-up crops, or intentionally dark scenery - it was the difference between native EX, and the nanoFlash, that was of interest; this way I guess there was nothing wrong with this methodology, even though it was far from scientific. However, I have come to the conclusion that illustrating this kind of issues with stills is basically inappropriate in that in the moving video, the noise artifacts are shimmering, thus becoming even more noticeable - and NO still screen grab can show that. While I'm typing this on my PC, Vegas is rendering a particularly noisy clip from my nanoFlash, on which I'm testing various settings of a NR filter. My purpose is to check whether the noise can be minimized while keeping most of the picture improvements that recording with the nanoFlash at 100 Mbps brought about... I wish I had an upload Internet connection fast enough to post this clip somewhere for you to see - this is a typical example of a well lit scene, shot with noise-reducing settings of the EX1 (like the gain at -3 dB, crispening in the positive territory, etc.), and yet it contains areas literally swarming with noise! |
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