How does MPEG video really compare to TV, VHS, laserdisc ?
VHS picture quality can be achieved for film source video at about 1 million bits per second (with careful application of proprietary encoding methods). Objective comparison of MPEG to VHS is complex and political. The luminance response curve of VHS places -3 dB (50% response, the common definition of bandlimit) at around analog 2 MHz (digital equivalent to 200 samples/line). VHS chroma is considerably less dense in the horizontal direction than MPEG’s 4:2:0 signal (compare 80 samples/line equivalent to 176 !!). From a sampling density perspective, VHS is superior only in the vertical direction (480 luminance lines compared to 240). When other analog factors are taken into account, such as interfield crosstalk and the TV monitor Kell factor, the perceptual vertical advantage becomes much less than 2:1. VHS is also prone to such inconveniences as timing errors (an annoyance addressed by time base correctors), whereas digital video is fully discretized. Duplication processes for pre-rec
VHS picture quality can be achieved for source film video at about 1 million bits per second (with proprietary encoding methods). It is very difficult to objectively compare MPEG to VHS. The response curve of VHS places -3 dB at around 2 MHz of analog luminance bandwidth (equivalent to 200 samples/line). VHS chroma is considerably less dense in the horizontal direction than MPEG source video (compare 80 samples/ line to 176!). From a sampling density perspective, VHS is superior only in the vertical direction (480 lines compared to 240)… but when taking into account interfield magnetic tape crosstalk and the TV monitor Kell factor, not by all that much. VHS is prone to timing errors (which can be improved with time base correctors), whereas digital video is fully discretized. Pre-recorded VHS is typically recorded at very high duplication speeds (5 to 15 times real time playback), which leads to further shortfalls for the format that has been with us since 1977. Broadcast NTSC qualit
VHS picture quality can be achieved for source film video at about 1 million bits per second (with proprietary encoding methods). It is very difficult to objectively compare MPEG to VHS. The response curve of VHS places -3 dB at around 2 MHz of analog luminance bandwidth (equivalent to 200 samples/line). VHS chroma is considerably less dense in the horizontal direction than MPEG source video (compare 80 samples/ line to 176!). From a sampling density perspective, VHS is superior only in the vertical direction (480 lines compared to 240), but when taking into account interfield magnetic tape crosstalk and the TV monitor Kell factor, not by all that much. VHS is prone to timing errors (which can be improved with time base correctors), whereas digital video is fully discretized. Pre-recorded VHS is typically recorded at very high duplication speeds (5 to 15 times real time playback), which leads to further shortfalls for the format that has been with us since 1977. Broadcast NTSC quality
A. VHS picture quality can be achieved for source film video at about 1 million bits per second (with proprietary encoding methods). It is very difficult to objectively compare MPEG to VHS. The response curve of VHS places -3 dB at around 2 MHz of analog luminance bandwidth (equivalent to 200 samples/line). VHS chroma is considerably less dense in the horizontal direction than MPEG source video (compare 80 samples/line to 176!). From a sampling density perspective, VHS is superior only in the vertical direction (480 luminance lines compared to 240)… but when taking into account (supposedly such things as) interfield magnetic tape crosstalk and the TV monitor Kell factor, the perceptual vertical advantage is not all that significant. VHS is prone to such inconveniences as timing errors (an annoyance addressed by time base correctors), whereas digital video is fully discretized. Pre-recorded VHS is typically recorded at very high duplication speeds (5 to 15 times real time playback spe
