Is it normal? My DVD recorder records dvd with bit rate 4505.6?

[szalaikornel]

My friends DVD recorder records video with variable bit rate 9545.8 (2 hours on one disc). If I record in that mode my variable bit rate is 4505.6. Why?

[Baldrick]

The 9545.8 is probably the MAX bitrate or else would 2 hour be around 8.5GB(use a bitrate calculator to calculate the size, see our tools list).

How do you check the bitrate?

[szalaikornel]

i make mpg from the disc and then i open the file in WOMBLE MPEG WIDEO WIZARD. I can see there whats the bitrate

[redwudz]

You could also use Gspot and select one of the VOBs from the DVD disc to check the bitrate.

[szalaikornel]

Yes thats OK but does someone know why is my dvd recorder recording 4505 bitrate, and my friend's 9500 ?

[Baldrick]

Compare the file size and ignore what it says about the bitrate because it can't be correct if it's a 2hours on dvd-r(4.7gb).

[szalaikornel]

I dont know if its important. My friend's dvd recorder can record to disc only. My recorder records to HDD. But the files recorded on his recorder in mode of 2 hours are 9500 bitrate. My recording on HDD of 2 hours is 4500

[DB83]

There are usually 3 recording modes (there are actually more but are not worth mentioning)

XP mode = 1 hour or max of approx 9500 kbps (video and audio)
SP mode = 2 hour or max of approx 4500 kbps
LP mode = 4 hour or max of approx 4500 kbps but using half video (352*576) whereas SP mode uses full video (720*576) - PAL video

The only way that a two hour mode could have a bit rate of > 9500 kbps if it used half video or smaller and there is no sense in doing that.

[szalaikornel]

Well both are recorded in SP mode. Here are the pictures of the details.



sp-friend.bmp

[midnightsun]

check size in bytes, multiply by8, divide by duration in minutes, divide by 60 -> bitrate in bits/s

it isn't that hard

[jman98]

The only way that a two hour mode could have a bit rate of > 9500 kbps if it used half video or smaller and there is no sense in doing that.

That is a common misconception. Video resolution has nothing to do with the final size. A video file of 352x576 recorded at a constant bit rate of 4000 Kbps will have the same size as a 720x576 video recorded at the same bit rate. (Well, I mean "same size" roughly. There will certainly be some minor difference in the 2 encodes.) The 352x576 video will not be half the size as the 720x576 video at the same bit rate.

The 2 examples in the original poster's link a message or two above this show that the PEAK (very important) bit rates differ. Peak bit rate is the maximum bit rate used and has nothing to do with the average bit rate used. The average bit rate used will be the best indicator of final file size. It seems that the friend's DVD recorder can use a higher bit rate when necessary but both machines may use average bit rates of about the same value.

[szalaikornel]

Thanks jman98!