Lobstah Posted May 4, 2007 Posted May 4, 2007 First off . . . N I C E piece of software LUK! Curious about the time displayed along with number of sectors, etc. Am I correct in assuming that 510 minutes of recording time on a 4.7gb blank disk is for recording audio? If so, is it possible to display the recording time for SP Mpeg2 video? . . . or maybe both? Since 510 is already calculated, there's probably a constant that could be used to derive the video time. Spent an hour searching the forum before posting this, hope I didn't miss something.
necrocracker Posted May 4, 2007 Posted May 4, 2007 The problem is that MPEG2 is variably compressed. You can have a full DVD-5 that has any where from 60min to 180min of video. It also depends on what type of audio you use and other factors. I also think that your SP definition will vary between hardware and software. I think it would seem more confusing to some users to see this method. At the same time, the amount of 44.1k 16b CDA audio I can fit on a DVD has much meaning either. Maybe just don't show the time for anything other than CD?
Lobstah Posted May 4, 2007 Author Posted May 4, 2007 Thanks for the feedback. You are right about the variable bitrate, but the audio has the same problem. I was just wondering since someone came up with a stardard audio bitrate to calculate from, that the same could be done for video. For instance, using a blank DVD-RAM in my Panasonic, the disk-info screen tells me I have 2 hours of video that I can record in Standard Play mode. If I change modes, it adjust the time accordingly. Now, when I remove the DVD-RAM from the living room and place it in my PC (Samsung DVD recorder), it tells me I have 510 minutes. And if I have a 1-hour recording on it, the Panasonic tells me I have 1 hour of space left, while the Samsung under IB tells me I have 250 minutes of space left. I was hoping that we could select a bitrate as a benchmark . . . say . . . a fixed bitrate that would allow a 2-hour recording on 1 single-sided DVD, and calculate video time from there. It really isn't a big deal for me, I was just curious about how the "510" is being calculated, and what it actually represents.
mmalves Posted May 4, 2007 Posted May 4, 2007 It really isn't a big deal for me, I was just curious about how the "510" is being calculated, and what it actually represents. That time is calculated based on a 1X data CD-ROM read speed, which has 2.048 bytes per sector read at 75 sectors/second, resulting in 153.600 bytes read per second. 4.706.074.624 / 153.600 = ~30638,5 seconds / 60 = ~510,64 minutes
Lobstah Posted May 4, 2007 Author Posted May 4, 2007 Thank you for the info. That definitely answers my question. It's what I suspected, but I wasn't really sure until you supplied the numbers.
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