4GB is a safe bet for best quality stream, but it depends on the encode. For iPad its scaled down. Assuming top encode rate is 1Mbps. 1Mbps * 7200 seconds = 7

4GB is a safe bet for best quality stream, but it depends on the encode. For iPad its scaled down. Assuming top encode rate is 1Mbps. 1Mbps * 7200 seconds = 7200 Mbit / 8 = 900 Mbytes