Members rasputin1963 Posted April 8, 2008 Members Share Posted April 8, 2008 My JVC EVERIO Camcorder records video in MPEG2 format, and stereo audio in AC3 format. What exactly is AC3 format, and what's it good for? Thanks in advance, ras Link to comment Share on other sites More sharing options...
Members blue2blue Posted April 8, 2008 Members Share Posted April 8, 2008 I'll tell you if you change your avatar photo. OK... just in case I'm not around. First change your avatar, then click here. Link to comment Share on other sites More sharing options...
Members rasputin1963 Posted April 8, 2008 Author Members Share Posted April 8, 2008 Nuthin' doin'! Surely you recognize Terry Jones from the Pythons doing his classic naked organist routine? Link to comment Share on other sites More sharing options...
Members blue2blue Posted April 8, 2008 Members Share Posted April 8, 2008 Just 'cause it's Terry Jones doesn't make it right. Link to comment Share on other sites More sharing options...
Members deanmass Posted April 9, 2008 Members Share Posted April 9, 2008 I vote to keep Terry... From web: Dolby's third digital audio coding technology based on a perceptual coding method. It is more advanced than AC-2 and provides six channels of audio in less space than two-channel stereo CD. AC-3 and "Dolby Digital" are synonymous. Sounds like really advance sequential panning to me... Link to comment Share on other sites More sharing options...
Members rasputin1963 Posted April 9, 2008 Author Members Share Posted April 9, 2008 I'm just wondering, because this camcorder produces files which apparently ADOBE AFTER EFFECTS 7 doesn't "like". The audio from my camcorder-- ac3-- never gets processed correctly, nor does the video (mpeg2) unless I convert the whole mess to a basic AVI first. But when I convert to a basic AVI, considerable quality in the video image is sacrificed: there are little horizontal lines across the screen. I'm just wondering what the supposed great advantage of ac3 audio is for a video hobbyist like myself... I don't think my camcorder is negotiating audio with six channels, just the two. We have entered a "tower of Babel" era with regards to codecs, I fear... Link to comment Share on other sites More sharing options...
Members doug osborne Posted April 9, 2008 Members Share Posted April 9, 2008 AC3 is the codec (compression/decompression) used by Dolby Digital. DD is used to carry and deliver audio on DVD (and Blu Ray) and ATSC digital television. It's used by some camcorders because the audio takes up 1/10th the space on the camcorder's storage than PCM audio. Some camcorders do record 5.1-channels. DD is lossy - 90% more or less of the original data is thrown away in the compression to DD. Perceptual Coding is used to figure out what is to be discarded - stuff that is masked by other, more prominent stuff (louder, in the same frequency range, etc.). DD can carry from one to six channels of audio and deliver it over an SPDIF digital connection or over digital broadcast/cable/satellite. DD audio is mixed with the MPEG2 video. The video and audio can be split with a variety of software tools. No Tower of Babel here, since DD is the most prominent lossy codec (with DTS close behind, and other lossy or lossless codecs on Blu Ray). Dolby Labs has an exclusive license for AC3 on DVD, so tools can be limited in how they work with DD (fearing violation of federal law prohibiting circumvention of digital encryption on DVD, for example). --- Little horizontal lines are not a feature of AVI - somewhere, there is a software tool that will allow you to split the audio and video without these problems. Keep the avatar. Link to comment Share on other sites More sharing options...
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