Authoring: geography

• Filling a CD-ROM or CD-ROM/XA or CD-I disc must be carefully thought out so that sufficient content is provided, with proper quality.
• One can trade off space and quality in images, video, and audio.
• Thus, more or higher quality video may force the audio to be of lower quality, if space is too constrained.
• CD-I discs can be filled by an hour of standard CD audio (CD-DA).
• They can also store 2 hours stereo ADPCM level A, or 4 hours of level B, or 16 hours of level C.