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Programming Forum and web based access to our favorite programming groups.[Edited: For typo reasons] I've developed a method of compressing AVI files (the video portion), and want to set a goal to work with! I've currently researched the internet for current lossless video compression ratios, and I'm a bit. I've seen some claiming ranges from 4:1 all the way to 10:1 (which seems a bit too far fetched for most videos). Does anybody know of a GOOD lossless video compressor that I can compare to. I'm going along the assumption that most lossless video compressors result in about a 2:1 to 3:1 ratio on MOST videos. Is this too far fetched a goal to set? Currently, all I'm comparing with in WinZIP and WinRAR. So far, my compression method (which surprisingly uses a variant of RLE encoding that I came up with) beats both. WinZip on average gave about a 1.6:1 ratio, WinRAR a 2.8:1 ratio, and mine gives about a 3.4:1. Thanks... Respectfully, Eric D. Brown
Post Follow-up to this message"Eric D. Brown" <nospam@nowhere.com> wrote in message news:10n0nqir9525qc7@corp.supernews.com... > I've developed a method of compressing AVI files (the video portion), and > want to set a goal to work with! I've currently research the internet for > current lossless video compression ratios, and I'm a bit. I've > seen some claiming ranges from 4:1 all the way to 10:1 (which seems a bit > too far fetched for most videos). > depends, one can, eg, losslessly use motion compensation, which can help (if for final encoding one is using arithmatic or huffman coding, motion compensation can make a lot more values closer to 0). > Does anybody know of a GOOD lossless video compressor that I can compare > to. I'm going along the assumption that most lossless video compressors > result in about a 2:1 to 3:1 ratio on MOST videos. Is this too far > fetched a goal to set? > no, I got a bit better myself, around 1:5 to 1:7 for my test videos (crappy webcam recordings of me walking around my room). I expect a little better compression with higher quality video, just I would have to come by/create some or such... largely, one of the drawbacks was in places where there was no motion, still having a lot of noise and similar which generally contributes to a larger frame. > Currently, all I'm comparing with in WinZIP and WinRAR. So far, my > compression method (which suprisingly uses a varient of RLE encoding that > I came up with) beats both. WinZip on average gave about a 1.6:1 ratio, > WinRAR a 2.8:1 ratio, and mine gives about a 3.4:1. > that is likely because at least rle can exploit runs of the same value pretty well. winzip uses deflate, which is based on lz77, which is not very good for graphical data in many cases. I was having some success with: motion prediction (I split the frame essentially into the motions from the previous to the current frame, and the difference between the real frame and the predicted one); a subtractive filter (for differences between adjacent pixels); rle+huffman coding. > Thanks... > > Respectfully, > Eric D. Brown
Post Follow-up to this message> Does anybody know of a GOOD lossless video compressor that I can compare > to. I'm going along the assumption that most lossless video compressors > result in about a 2:1 to 3:1 ratio on MOST videos. Is this too far > fetched a goal to set? The yardstick i use for comparing with my own lossless video codec is the ffv1 video codec which is a part of the ffmpeg project. You might want to try it.
Post Follow-up to this messageEric D. Brown wrote: > I've developed a method of compressing AVI files (the video portion), > and want to set a goal to work with! I've currently research the > internet for current lossless video compression ratios, and I'm a bit >. I've seen some claiming ranges from 4:1 all the way to 10:1 > (which seems a bit too far fetched for most videos). > > Does anybody know of a GOOD lossless video compressor that I can compare > to. I'm going along the assumption that most lossless video compressors > result in about a 2:1 to 3:1 ratio on MOST videos. Is this too far > fetched a goal to set? > > Currently, all I'm comparing with in WinZIP and WinRAR. So far, my > compression method (which suprisingly uses a varient of RLE encoding > that I came up with) beats both. WinZip on average gave about a 1.6:1 > ratio, WinRAR a 2.8:1 ratio, and mine gives about a 3.4:1. > > Thanks... > > Respectfully, > Eric D. Brown Thanks moogie & cr88192 for your feedback... much appreciated. I also have another question (based upon researching), what exacted is bitwise encoding? I've tried searching for the meaning in a few places; however, most explanations are somewhat vague. Let's say I wanted to take the first bit of every byte and put them into an array... continuing to the next bit value of every byte. I then run an RLE compression on those bit groups (again, based on the placement that they appear in the byte). Would that be called a bitwise encoding method? Thanks... Respectfully, Eric D. Brown
Post Follow-up to this message"Eric D. Brown" <nospam@nowhere.com> wrote in message news:10n2qag5kugb182@corp.supernews.com... > Eric D. Brown wrote: > > Thanks moogie & cr88192 for your feedback... much appreciated. I also > have another question (based upon researching), what exacted is bitwise > encoding? I've tried searching for the meaning in a few places; however, > most explanations are somewhat vague. > > Let's say I wanted to take the first bit of every byte and put them into > an array... continuing to the next bit value of every byte. I then run an > RLE compression on those bit groups (again, based on the placement that > they appear in the byte). Would that be called a bitwise encoding method? > probably. I would guess "bitwise" would sensibly refer to things taking decoded input/output as a bitstream vs a byte or wordstream... however, I am not very authoritative on matters of definition.
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