ajmoss
16th March 2002, 16:05
MPEG files store data in packets of 2048 bytes, the same size as a frame on a CD. An MPEG of a PAL broadcast has a key frame every 0.48 seconds, or every 36 frames on a CD. Video CDs store file data in the checksum area of the CD. Am I right in thinking that they still store data in 2048 byte packets, but there are 41 blocks between the start of successive key frames?
I understand how MPEG compression works (discrete cosine transform, followed by low-pass filter). If I record an MPEG-1 at about 2.4 to 3 megabits/second, then edit it down to the bit rate of a VCD, will I get the same quality result that I'd get if I had performed the original capture in VCD format? To put it more simply, is the low-pass filtering done in the sensible and intuitive way, as some sort of cut-off?
The first track of a VCD contains information that a DVD player needs to play the VCD. If you put a VCD in a computer with no VCD software installed, all you see are these files. Can I put additional files into this first track - specifically, an installer for a VCD player for Windows? Indeed, which VCD player software would you recommend?
As a VCD contains no additional checksum information, it's more important to protect it from scratches. What method should I use to send a single VCD through the post safely, whilst minimising the cost and mass? Is it sufficient to use a CD envelope (paper or plastic) inside a normal postal envelope, or would a compact jewel case be advisable?
I understand how MPEG compression works (discrete cosine transform, followed by low-pass filter). If I record an MPEG-1 at about 2.4 to 3 megabits/second, then edit it down to the bit rate of a VCD, will I get the same quality result that I'd get if I had performed the original capture in VCD format? To put it more simply, is the low-pass filtering done in the sensible and intuitive way, as some sort of cut-off?
The first track of a VCD contains information that a DVD player needs to play the VCD. If you put a VCD in a computer with no VCD software installed, all you see are these files. Can I put additional files into this first track - specifically, an installer for a VCD player for Windows? Indeed, which VCD player software would you recommend?
As a VCD contains no additional checksum information, it's more important to protect it from scratches. What method should I use to send a single VCD through the post safely, whilst minimising the cost and mass? Is it sufficient to use a CD envelope (paper or plastic) inside a normal postal envelope, or would a compact jewel case be advisable?