discussion:29 fps vs 23.97 and vcd vs svcd

[PIRATE_4_FUN]

Why is there a video/sound sync issue with the 23.97 fps. The sound ALWAYS seems to be >just slightly< behind the video on a 23.97 ntsc film. I do have an APEX 600 which will have a sound/sync issue with a few dvd's but not many, so I am hoping maybe its my Apex which I've been told has had sound issues! Whats the deal with the SVCD's??, Ive always burned them into VCD's and they come out quite well, is there much of a difference?, does it take any longer to make the SVCD and is the AVI file for the svcd any different?

[kriskim]

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On 2001-09-23 16:07:07, PIRATE_4_FUN wrote:
Why is there a video/sound sync issue with the 23.97 fps. The sound ALWAYS seems to be >just slightly< behind the video on a 23.97 ntsc film. I do have an APEX 600 which will have a sound/sync issue with a few dvd's but not many, so I am hoping maybe its my Apex which I've been told has had sound issues! Whats the deal with the SVCD's??, Ive always burned them into VCD's and they come out quite well, is there much of a difference?, does it take any longer to make the SVCD and is the AVI file for the svcd any different?

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i'm not sure i understand your first question. what 23.976fps source are you using? if you have a dvd to play on ntsc tvs, it will never be 23.976, it will always be 29.97 fps (either interlaced or 23.976fps with 2:3 pulldown flags). if you have a video file on comp that is 23.976, the encoder may have ivtcd the video, but not adjusted the sound to the new framerate (which would explain why the sound is behind the video. the sound was "cued" for 30frame/sec, and instead, the video is runnig at 24frames/sec, ie. faster).

svcd has more than twice the resolution of vcd (480x480/480x576 ntsc/pal). it has more than twice the bitrate for vid/aud 2726kbps max i believe). it also uses vbr mpg2 (like dvds). svcds are just basically dvds with lower bitrates so that they can be burnt onto 2 or 3 regular cdr media. svcds are generally MUCH better quality than vcd, a good svcd encode can be difficult to differentiate with the original dvd.

the mpg file of svcds are mpg2, and can only be played with a software dvd player (like powerdvd or windvd) or a codec can be found soemwhere on the net to play in wmp (altho installing powerdvd or windvd will allow playback in wmp). vcds are regular mpg1.