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Old Apr 23, 2007, 4:13 AM   #11
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Thanks, Rudo, for your post. You say "When you convert the MPEG4 quality will allways at least slightly decrease." Now, is this difference very noticable or is the "decrease in quality" so slight that it would make very little difference to the human eye?

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Melvyn
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Old Apr 23, 2007, 5:37 AM   #12
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misquitas wrote:
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Thanks, Rudo, for your post. You say "When you convert the MPEG4 quality will allways at least slightly decrease." Now, is this difference very noticable or is the "decrease in quality" so slight that it would make very little difference to the human eye?

Regards,

Melvyn
Depends on the quality of your converter and your personal settings. But if you convert to DivX / XviD, the decrease can be very un-noticable (is that a word?). If you want to convert tot DVD, quality can be very similar as original. The decrease won't be very noticable (again, depending on what kind of settings you use) Doom9 forum is indeed a good forum to ask what is best......

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Old Apr 27, 2007, 7:35 AM   #13
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I was looking for a digicam that recorded the best quality video in the smallest possible file sizes and I found it: the Sanyo Xacti CG65. It records in the new MPEG-4 AVC (advanced video coding, alsoreferred to asH.264) with stereo audio in AAC (advanced audio coding). This allows you to record over an hour of very good quality video per gigabyte, unlike MJPEG cams that do less than 8 minutes. It is by far the camera that has the best video for the smallest file sizes at this point in time. The video is better than most camcorders and looks great on TV. And it's a 6MP digicam. I put up a mini review of it and some video samples in the Sanyo forum here. There is also the Sanyo CG6 which is less expensive and available at Walmart, it records using MPEG-4 SP (simple profile).

I can't imagine that those who say that MPEG-4 video is bad quality have much experience with it. If you have experience with Xvid and DivXyou know it's a capable codec. And MPEG-4 AVC /H.264 is one of the premier codecs for both HD-DVD and Blur-Ray.
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Old Apr 28, 2007, 2:30 AM   #14
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Caelum wrote:
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I can't imagine that those who say that MPEG-4 video is bad quality have much experience with it. If you have experience with Xvid and DivXyou know it's a capable codec. And MPEG-4 AVC /H.264 is one of the premier codecs for both HD-DVD and Blur-Ray.
I have never said that mpeg4 asp or mpeg4 avc is a bad codec. It's an excellent codec. In fact, I reencode my digicam videos with XviD. However, especially mpeg4 AVC is such a sophisticated codec, that an image processor cannot really use it. Even PCs have problems coping with mpeg4 AVC. All digicams with mpeg4 video use a very lousy implementation of mpeg1 in an mpeg4 container. In fact if you analyse such videos, then you see that every I-Frame is followed by 99 P-Frames. There are no B-Frames and motion compensation, which are typical for advanced mpeg4 video, at all.
As it is now good mjpeg videos from Canon can be converted with much better quality to real mpeg4 than the lousy mpeg4 videos, which are in reality only poor mpeg1 videos. The word mpeg4 is used only as buzz word.
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Old Apr 28, 2007, 6:28 AM   #15
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kassandro wrote:
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[...] All digicams with mpeg4 video use a very lousy implementation of mpeg1 in an mpeg4 container. [...] lousy mpeg4 videos, which are in reality only poor mpeg1 videos. The word mpeg4 is used only as buzz word.
I'm sorry but this is completely and blatantly inaccurate. I did analyse thefiles of the Sanyo Xacti series and they are in no way MPEG1 video streams inside MPEG4 containers!? (And by MPEG4 container I assume you mean MPEG-4 part 14, the MP4 file format, but you are stating "All digicams", howeversome digicams store MPEG-4 streams inan AVI container, which has nothing to do with the MPEG-4 standard.)Someencode their video streams usingtheMPEG-4 simple profile codec, the Sanyo Xacti CG65 encodes it's video stream using the MPEG-4 advanced video codingcodec (AVC/H.264). I doubt you have any experience at all with the CG65 tomake your false blanket statement. Clearly if youhad looked atany ofthe Sanyo Xacti video streams and you had the most basic understanding of MPEG1 vs. MPEG4 encoding you would not have written that, so I probably shouldn't be bitting on this nasty troll nugget.
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Old Apr 28, 2007, 10:03 AM   #16
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Casio 750 and 850 stills have exceptional presence. Their videos are more than adequate to record those special times. Many aspects of these cameras besides portability rival DSLRs.

Whatever camera you get, get a good leather case that was made for it that you can attach to your belt, put in your purse or clip to your pocket. Makes all the difference.
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Old Apr 28, 2007, 2:20 PM   #17
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Caelum wrote:
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kassandro wrote:
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[...] All digicams with mpeg4 video use a very lousy implementation of mpeg1 in an mpeg4 container. [...] lousy mpeg4 videos, which are in reality only poor mpeg1 videos. The word mpeg4 is used only as buzz word.
I'm sorry but this is completely and blatantly inaccurate. I did analyse thefiles of the Sanyo Xacti series and they are in no way MPEG1 video streams inside MPEG4 containers!?
"Container" was the wrong word. Besides I-Frames MPEG1 uses only P-Frames without any motion compensation. Now, all the digicam mpeg4 videos - I have seens various such videos from Casio, Kodak, etc. - use exactly the same very primitive concepts and nothing else. Thus its essentially mpeg1. Motion compensation is the crucial concept of all advanced video codecs and it is way beyond the scope of a digicam image processor.
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Old Apr 29, 2007, 10:46 AM   #18
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kassandro wrote:
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"Container" was the wrong word. Besides I-Frames MPEG1 uses only P-Frames without any motion compensation. Now, all the digicam mpeg4 videos - I have seens various such videos from Casio, Kodak, etc. - use exactly the same very primitive concepts and nothing else. Thus its essentially mpeg1. Motion compensation is the crucial concept of all advanced video codecs and it is way beyond the scope of a digicam image processor.
You can insist the earth is flat based on your limited knowledge, it doesn't make it so. I've been using MPEG since the Amiga days... and MPEG-1had I, P and B frames and motion estimation since the very start. Motion compensationis adecoding concept only, and it does apply to MPEG1 decoding as well. So your statement is, again I'm sorry to say, completely incorrect.Back then most computers had difficulty playing MPEG1 but there werespecialized chips that accelerated it's encoding and decoding (such as found on ReelMagic cards at the time). Today, the Sanyo Xacti CG65 has a new specialized LSI chip called the "pure force engine III" which was specially designed to process, encode and decode MPEG-4 AVC/H.264 video. The video quality produced by the CG65 using variable bit-rate MPEG-4 AVC encodingwould be impossible to encode at the same quality using MPEG-1 because of the differences in how they handle compression blocks, so it isin no way"essentially mpeg1". And it is not beyond the scope of that digicam's processor. So I guessyou also believe Sony's and Panasonic's AVCHD camcorders are using "essentially mpeg1". Sigh, I really shouldn't be biting on this bait...
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