MPEG-4: Optimization of Picture Quality and Data Rate

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Compromise: Quality Vs. Resolution

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Resolution	Bitrate Video MPEG-4	Data Rate Audio	Overall	Quality	Length of Film CD-R 74	Length of Film CD-R 80	Length of Film CD-R 99
Video	Fast-Motion-Codec	Fraunhofer Codec	Data Rate	Row 0 - Cell 4	Burn to CD-R	Burn to CD-R	Burn to CD-R
176 x 112 Pixels	adaptive, max. 6000 kBit/s	128 kBit/s, 44 KHz, Stereo	37 kB/s	very good	300 min	323 min	370 min
240 x 192 Pixels	adaptive, max. 6000 kBit/s	128 kBit/s, 44 KHz, Stereo	45 kB/s	very good	247 min	266 min	303 min
352 x 224 Pixels	adaptive, max. 6000 kBit/s	128 kBit/s, 44 KHz, Stereo	70 kB/s	very good	159 min	171 min	195 min
480 x 288 Pixels	adaptive, max. 6000 kBit/s	128 kBit/s, 44 KHz, Stereo	94 kB/s	very good	118 min	127 min	145 min
576 x 336 Pixels	adaptive, max. 6000 kBit/s	128 kBit/s, 44 KHz, Stereo	109 kB/s	very good	102 min	110 min	125 min
640 x 480 Pixels	adaptive, max. 6000 kBit/s	128 kBit/s, 44 KHz, Stereo	129 kB/s	very good	86 min	93 min	106 min
720 x 416 Pixels	adaptive, max. 6000 kBit/s	128 kBit/s, 44 KHz, Stereo	145 kB/s	very good	77 min	83 min	94 min

Especially in the case of DVD videos that have a playing time of more than 90 minutes, it is often the case that the storage capacity of a CD-ROM with just under 700 MB (CD-R80) is not sufficient. In order to avoid having to split the DVD video onto two CD-ROMs the average data rate should be reduced when carrying out the MPEG-4 encoding. In principle, there are two different ways of doing this. On the one hand, the resolution can be slightly reduced or, on the other hand, you have to marginally sacrifice picture quality, so that the data rate is lowered with a consistent resolution.

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All three video sequences were prepared with the slow motion codec and different bit rates. While the lowest resolution only requires 250 kBit/s, the resolution with 352 x 224 pixels needs as much as 700 kBit/s.