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Old Nov 17, 2005, 5:22 AM   #11
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Hi

I had not thought of using Windows Moviemaker as a compression tool - as indicated previously I tend to use Windows Media Encoder or RAD Video Tools.

One of the problems of course in sharing your clips using E-Mail is the limited file size you can send. Even a 30 sec clip at ca 2M data rate is ca 60M as it comes off the camera and if youcompress this to say 2M ( which Window Moviemaker can do ) to send by E-Mail then a lot of quality is lost.

I think it is betterto retain reasonable quality, using say a 10 fold reduction, then use one of the Upload sites such ashttp://www.yousendit.com to deposit your movie and let friends download from there.

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Old Nov 18, 2005, 11:47 AM   #12
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Hello,

If going from 2MB/sec to 2MB/min (60:1 compression) is too much of a quality hit for you, try a higher quality setting using Windows MovieMaker (or other movie software). I wasrecommending that setting for very long movies such as 8 minutes to keep it and emailable size forAOL (16MB tops). If you shoot a 4 minute movie (half as long as 8 min), then it makes sense you can double the bitrate from 256Kb/sec to 512Kb/sec and still wind up with a 16MB movie which is ok to email using AOL. At that bitrate, it will be 2MB/sec compressed to 4MB/min which is 30:1 compression (still quite aggressive). That should be noticeably better quality than 60:1 compression. Note that since the Canon S2 movies are already compressed about 13:1 in 640x480 30 fps mode, an additional 60:1 compression is an actual 780:1 total compression which is very impressive. Movies require very high bitrates so consider yourself lucky to even have a movie option on a digicam. Maybe a few years down the road we will have the technology to have full screen movies at even higher framerates such as 60 to 100 fps to better match our screen refresh rates. F.Y.I. a1600x1200 movie at 60 fps uncompressed would fill a 1GB memory card in only 3 seconds and only about 2 seconds at 100 fps. Have fun.
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Old Nov 19, 2005, 4:36 AM   #13
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Some of the ISPs in the UK obviously have a muchlower limit on the size of E-Mail attachments since I recently tried to send a 5M file to a friend and this was rejected by his server as too big.

So the Upload Sites, e.g. the one I mentioned before, can be very useful for sharing video clips.

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Old Nov 22, 2005, 9:18 AM   #14
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Hi - I use 2Gb and a 1GBSD Cards with 66X Read/Write with no issues for movies. They work fine - the longest single movie clip I have taken was of a speech (filled a 1GB card) otherwise in most cases I fill the cards up with many clips, so, sofar the1GB limit imposed by the camera software has never impacted me -memory space yes!
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Old Nov 23, 2005, 3:34 PM   #15
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@[email protected]:
All Canon cameras use mjpeg for movie compression. In particular, each frame of a movie is compressed seperately as a jpeg picture, whence halving the frame rate will also halve the video size. mjpeg is a very simple compression method, but also very inefficient compared with all kinds of mpeg compression techniques, which are based on delta frames, i.e. differences of frames. For these more sophisticated compression methods halving the frame rate has indeed a much a smaller impact on the video size, but most digicams use the inefficient mjpeg and then the frame rate has a maximal impact on compression size.
Reducing the resolution from 640x480 to 320x240 does not reduce compression size by 75%, because if 320x240 is used you have much more detail per pixel than with 640x480. In other words with 640x480 the pixel are smoother than with 320x240 if the same object is filmed. Consequently, compression per pixel is higher with 640x480 than with 320x240 and the compression is much smaller than 75%.

Even with the best compression techniques you cannot expect 2MB/min

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Old Nov 23, 2005, 3:40 PM   #16
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This forum uses the most horrible blog software I have ever seen. It doesn't work with Firefox and it did cut my last message (I couldn't edit either). Here is the remainder:

for a [email protected] fps clip. That is simply nonsense. Because my S1 produces somewhat oversharpened videos and the S2 probably does the same, you should be very happy, if you achieve 12 MB/min and to achieve such a rate with good image quality you have to use the combination of the best tools, i.e. Avisynth/Virtualdub/XviD and you need a lot of experience. Microsoft movie maker is simply rediculous.
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Old Nov 23, 2005, 3:42 PM   #17
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This forum uses the most horrible blog software I have ever seen. It doesn't work with Firefox and it did cut my last message (I couldn't edit either). Here is the remainder:

for a [email protected] fps clip. That is simply nonsense. Because my S1 produces somewhat oversharpened videos and the S2 probably does the same, you should be very happy, if you achieve 12 MB/min and to achieve such a rate with good image quality you have to use the combination of the best tools, i.e. Avisynth/Virtualdub/XviD and you need a lot of experience. Microsoft movie maker is simply rediculous.
forum uses the most horrible blog software I have ever seen. It doesn't work with Firefox and it did cut my last message (I couldn't edit either). Here is the remainder:


for a [email protected] fps clip. That is simply nonsense. Because my S1 produces somewhat oversharpened videos and the S2 probably does the same, you should be very happy, if you achieve 12 MB/min and to achieve such a rate with good image quality you have to use the combination of the best tools, i.e. Avisynth/Virtualdub/XviD and you need a lot of experience. Microsoft movie maker is simply rediculous.
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Old Nov 23, 2005, 4:14 PM   #18
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Hi,

This is a response to kassandro's posting. 2MB/min movie datarate IS possible. I have tried it using Windows XP movie maker. Thequality is acceptable.At that datarate, Windows XP movie maker will generate a 320x240 movie size at 30 fps and if viewed 100% on a 1280x960 display or even a 1600x1200 display, the quality is quite acceptable. It is justa matter of preference. If small filesize is most important then this IS an option. I found that the next higher setting of 384Kb/sec has better sound and similar image quality. You can even zip the final movie to get another 3 or 4% compression. I would say try it before you say you cannot expect 2MB/min. You might be surprised. If the movie doesn't have a lot of movement then this becomes more of an option. Enjoy.
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Old Nov 24, 2005, 1:41 PM   #19
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Clearly compression size is very motion dependant. I can only speak of my [email protected] fps video clips shot with a Powershot S1. This clips usually contain a significant amount of motion (otherwise I would make still pics), but usually I use a tripod to avoid shake, which is very negative for compression. The image stabiliser only keeps the pics sharp. On a sharp computer screen 340x280 resized to the full screen looks ugly. It looks better on a soft tv screen, but I know no DVD player, which supports Microsoft's WM9 codec. On the other hand avi's encoded with DivX/XviD can't be played on many DVD players. I have tested Microsoft's codec, but it can't live up to it promises and virtually all independent codec tests confirm my observation.
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Old Nov 25, 2005, 6:04 AM   #20
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Thanksto all for those useful & though provokingcomments.

Since there are a lot of experts amongst you, may I pose a further question about burning movies to VCD or DVD to display on a TV ( CRT ).

I startedto try this in order to evaluate movies from digicams on the media I evenually wished to view them on. I also wanted to create some professional looking Slideshows, rather than just a series of JPGs on a CD, as I had done to date

I tried this using MS Moviemaker to createa Slideshow and wrote this to both VCD & DVD usingmy Sonic software "MyDVD".

The WMV files ( both 320x240 & 720x576 ) produced by Moviemaker are fine and the photos are perfectly stable on my PC (FP) for the 10 secs they are displayed in the movie and I would think all the frames are identical

When I burn them to VCD however, using MyDVD, the results are very disappointing.

Detailed photos in particular, e.g fine grasses or leaves, lookunstable. Thepicture has a moving, mottled, appearance as though all the individual frames are different e.g. slightly displaced ( ? ). I get the same effectwhen viewed either onmy PCor my TV. The same Slideshow WMV file burned to DVDis much better. Itlook identical to the original WMV fileon a PC but show a slight shimmering effect on TV - probably due to the 625 lines and the scanning.

If I view the same photos, which Iused for the Slideshow,on my TVas JPG files written to a CD and played on by DVD player, then these are perfectly stable.

Since the Slideshow WMV file produced by Moviemaker is fine, then the unstable effects are due toMyDVD and the VCD format.

If this happens to Slideshow WMV filesburned by MyDVD then presumably the same thing will happen to real movie WMV files burned the same way.It is obviously necessary to eliminate these effects before using the VCD TV display to evaluate the quality of digicam movies processed in the same way.

I have tried burning to VCD with Moviemaker ( HighMAT format ? ) but these will not play at all on my normal DVD player.

Any comments please on the causeof this and how toeliminate these effects.

Phil



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