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MPEG-2
Is it possible to compress an MPEG-2 at a data rate higher than 9 Mbps at 720×480? Do these specs look whack to you?
Video files must be encoded to the following specification:
MPEG-2
GOP Pattern: I Frames only
Image Size: 720×480 NTSC
Pixel Aspect Ratio: Square pixels (VGA)
Frame Rate: 29.97fps
Bit Rate: 20 mbps (20000 kbps)
Bit Rate Control: Constant bit rate
Quality/speed: Highest Quality
Deinterlace -
6 Replies
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Yes, but not for DVDs. We encode programs for playback on specialized systems used in museums, etc. for video displays. That hardward will accept mv2s at data rates much greater than DVD rates. That said, we don’t encode at 20Mbps. What hardware is playing this back? Also, we have to mux the audio and video for the specialized players.
John
Dual 2.5 G5 4 gigs RAM OS 10.4.3 QT7.0.3
Dual Cinema 23 Radeon 9800
FCP Studio 5 (FCP5.0.4, DVDSP4.0.2, Comp2.0.1, STP1.0.2)
Huge U-320R 1TB Raid 3 firmware ENG15.BIN
ATTO UL4D driver 3.50
AJA IO driver 2.1 firmware v23-28
SonicStudio HD DAW, Yamaha DM1000, Genelec Monitors -
I’ve checked the specs on a few commerical DVD’s here and 14 mbps seems to be the average data rate for them.
Walter Biscardi, Jr.
https://www.biscardicreative.com
HD Editorial & Animation for Food Network’s “Good Eats”
HD Editorial for “Assignment Earth”“I reject your reality and substitute my own!” – Adam Savage, Mythbusters
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Here’s the DVD spec from the MPEG group: https://www.mpeg.org/MPEG/DVD/Book_B/Video.html
As you can see the max bitrate for SD DVDs is 9.8Mbps. However, approaching that rate is not a good idea. Most posts I’ve seen suggest keeping the bitrate below 8Mbps. As the bit rate increases toward the max, more and more players will have problems successfully playing the DVD. You have a more breathing space if you use ac3 for the audio stream.
The cited MPEG spec states, “The maximum bitrate of 9.8 Mbit/sec is more restrictive than MP@ML’s 15 Mbit/sec limit. However, the point of diminishing returns (no visual difference between original video and compressed video) is widely known to be around 9 Mbit/sec.” I believe that MP@ML refers to the main definition for a MPEG stream (that includes more applications than DVD). However, DVD is restricted to 9.8Mbps. We encode our programs for our Alcorn-McBride player at 9Mbps with muxed audio. The Alcorn’s max rate is 15Mbps which is in line with the spec.
Michael, after looking up these specs I’m still curious about what hardware is calling for 20Mbps as this is outside the spec for MPEG. Perhaps it’s for HD which would imply a greater bitrate.
There’s a lot more expertise on this subject than mine on the DVDSP forum on the Cow.
John
Dual 2.5 G5 4 gigs RAM OS 10.4.3 QT7.0.3
Dual Cinema 23 Radeon 9800
FCP Studio 5 (FCP5.0.4, DVDSP4.0.2, Comp2.0.1, STP1.0.2)
Huge U-320R 1TB Raid 3 firmware ENG15.BIN
ATTO UL4D driver 3.50
AJA IO driver 2.1 firmware v23-28
SonicStudio HD DAW, Yamaha DM1000, Genelec Monitors -
I’m told that it’s going into something called a “Hippo”. We’re outputting multiple m2v’s that will play over multiple screens for a concert this week. It’s the usual telephone game from client to producer to creative. All I know for sure is that that’s the specs for what they want delivered. Have you ever heard of a “Hippo”? Preliminary google searches turned up nothing.
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We compress spots for electronic delivery w/ “DGSystems” and they require 20mb/s mpeg2 delivery.
For the Mac, we have found Sorensen Squeeze to do the trick. -
I’ve not heard of Hippo. If you get any more info, please post it.
John
Dual 2.5 G5 4 gigs RAM OS 10.4.3 QT7.0.3
Dual Cinema 23 Radeon 9800
FCP Studio 5 (FCP5.0.4, DVDSP4.0.2, Comp2.0.1, STP1.0.2)
Huge U-320R 1TB Raid 3 firmware ENG15.BIN
ATTO UL4D driver 3.50
AJA IO driver 2.1 firmware v23-28
SonicStudio HD DAW, Yamaha DM1000, Genelec Monitors
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