Divx bitrate comparison

[perdomot]

I'm turning my old vhs movies into XVCDs to play on my dvd player and was curious about how divx compares to mpeg 1. I know that creating disks with divx would mean I could only play them on my computer but I wonder what the bitrate/quality levels are. Most of my old vhs movies are less than 90 minutes long and with an audio of 128kbps, I usually end up using a bitrate of 2300-2400 for a 2 CD set. What divx bitrate would be comparable in quality to the above settings and if I still wanted to use two CD-Rs for my movies, what kind of quality can I expect by using a higher bitrate for divx? Thanks.

[Tommyknocker]

It would be a good idea to use the bit rate calculator on this site. And quality has always been subjective. So use what ever bit rate you want in several samples and decide which one you are willing to live with.

[perdomot]

Does that mean there is no object data comparison? Mpeg1 at 1150 bitrate is the same as divx at 1150? Hard to believe considering all the hoopla I hear about divx quality. There's got to be some sort of numerical comparison such as "Divx at 700kbps is equal in quality to 1150kbps of mpeg1". At least I hope so.

[Tommyknocker]

I do not know how to play the numbers game. I look at what settings I need for each project, and see if the quality is acceptable. Not very scientific, but it works for me.

[secretagent]

i think you are missing something here. 1150 kb is 1150 kb. but a divx at 1150 will be 12 times smaller than a mpeg at 1150

[Cecilio]

i think you are missing something here. 1150 kb is 1150 kb. but a divx at 1150 will be 12 times smaller than a mpeg at 1150

what do you mean it will be 12 times smaller than an mpeg of 1150. if i understand you, then the DIVX will be 12 times smaller than the DVD, but not 12 smaller than a vcd. the advantage of divx over mpeg, is that you can not only use a low bitrate and still get good quality, but you can use a higher reselution, than 352*240. you can use 512*400 and use a bitrate of 1150, and get a pretty clear picture, although for divx i recommend doing 2 pass vbr.

[ZippyP.]

i think you are missing something here. 1150 kb is 1150 kb. but a divx at 1150 will be 12 times smaller than a mpeg at 1150

What??????????????????????

If the bitrates (b/s) and the length (secs.) of the clips are the same then they will be the same size!

length times bitrate = file size

[secretagent]

divx is a form of compression. mpeg 1 has exact specifications very limited. you could easily fit 2 -3 hours of divx on a 700 mb cd. you cannot do that with a mpeg1. I thought he was asking about fiiting his movies on a disk or two and comparing quality. all i was suggesting was that he could go very high on bitrate on a divx file a still have more room than if he used mpeg1. i agree that bitrate x length = filesize. sorry if I worded my response incorrectly

[perdomot]

Well, the calculator gives me a bitrate of 948 for a 90 minute movie with 128 audio. That seems mighty low for a quality image. Anyone using a comparable bitrate for some of their projects that can vouch for this being a good setting?

[ZippyP.]

Sorry If I can't give you the exact answer that you're looking for but...Like secretagent said, the divx will be better than vcd in any case. Give it a try.

[flaninacupboard]

Perdomot,

Divx and MPEG1 at the same bitrate will look different. Now Divx is by no means perfect, and when people say it's DVD quality, they are lying

If you know what you're looking for, even a good Divx has obvious artifacts, as does MPEG1 and MPEG2, and -any- form of lossy compression.

The advice to try for yourself and see what you're happy with is the best anyone can give. I will say one thing though: Divx is usually used on DVD rips, which are high res, low in noise and professionally shot. Home movies are a whole different kettle of fish, and personally i don;t think Divx would be a good match. (basically Divx gets it's edge by relying on there being little motion for a long period [upto 250 odd frames] so when the camera is shaking, the kids are running, and you're panning from one side of the garden to the other, it won't do a very good job)

From a personal standpoint, i would create 352X576 MPEG2 VBR 100~5000kbps with 2200 average to fit 45 mins on a CD-r. This is CVD resolution, so should be playable on CDr for now, and when you buy a DVD burner, it's a DVD compliant resolution, so you won;t need to re-encode, but you will be able to fit 6 cd's worth on a DVDr

[jntaylor63]

DivX will give DVD quality. It all depends on the bitrate and input. As with DVD's, some look better than others.

With DivX, I find that you can get same quality at 2:1 or 3:1 ratio from a MPEG1/2 encode rate. If your DVD is 4.2 mbs, you can make a DivX at 2.1 mbs. Again, its depends on your input and even your software to do the encoding.

I have a standalone DivX player that displays to a 36" TV via S-Video. If I back-up a DVD with the above method, everyone thinks its the DVD. I can burn a back up of a LONG movie (LOTR, Titanic, Braveheart) on one DVD-R with AC3 and its the same as the DVD. (I do this rather than split to two DVD-Rs and I can copy to my laptop when travel)

Also, I do all of my home movies to DivX. I get more vidoe per DVD-R and I can copy the clips from the DVD-R to an other disk (DVD-R or CD-R) or to an other PC. A lot easier than autoring to a DVD and then trying to go back and share/copy segments. I capture as Raw AVI and then encode with DivX 5, 2 pass VBR

So, with the space on a CD-R, you can get better quality with DivX than Mpeg1. 1150 KBS as DivX will look a lot better than VCD. Yet it will be the same amount of playback time. (84 mins in this example) But you can only play back on PC or the new DVD/DivX players. Choice is yours.

p.s. I am a DivX fan, but I still try for DVD formats when I can.

[flaninacupboard]

Any chance of a clip of home movies in Divx? I really wouldn't think it could hack it, i'm interested to see what quality you're getting!

[flaninacupboard]

Another thought crossed my mind, does DivX support interlaced material? if not you'd either have to de-interlace, ar drop down to 320X240 resolution. that's a pretty good reason to stick to MPEG2 or DV if you ask me!!

[gll99]

I backed up some of my DVD's using #1 DVDRipper and the divx 5.05 codec set between 750 and 950 KB/s depending on the movie length 100 to 120 min average. My resolution was unchanged from the DVD at 720x480 and framerate also left as the DVD 23.97 (perhaps 24 fps film) or sometimes 29.976. After a few trials to get the size to time and bitrate ratio figured out I got pretty good at it. The quality of these movies viewed on my monitor or through my TV-out were excellent. One movie was 141 minutes long and I had to drop the bitrate to 650 kb/s and it really showed in the movie. The quality dropped off substantially. I ran that movie through DVDx and frameserved it to helix producer 9.01 and got a great 700mb encode in rmvb format. This longer movie looked superior in rm9 format than divx for the same output filesize.

I tried similar things using various capture apps to record from my VHS tapes to HD using the Divx 5.05 codec but do not like the results. Since the source is not as clean as DVD the quality of the output is much less at the comparable bitrate to the DVD encodes. It would be better to cap a vhs with less compression first then do some cleaning-up of the image and then apply the final codec such as DIVX 5 (or rm9) to fit the movie on 1 disc.

[DJRumpy]

Newer versions of DivX will handle interlaced sources. Expect resolutions around 640x272 at 800kbps for a movie that runs for 1.5 hours to look excellent.

Some of you are forgetting that DivX uses MPEG-4, which is based on the same basic principles of MPEG-2.

Well, the calculator gives me a bitrate of 948 for a 90 minute movie with 128 audio. That seems mighty low for a quality image.

948 is actually close to the sweet spot, and a hair to the high side for divx/xvid. Expect dvd quality at widths of 640 or higher, assuming your using multipass.

i think you are missing something here. 1150 kb is 1150 kb. but a divx at 1150 will be 12 times smaller than a mpeg at 1150

ZippyP. is correct. X number of bits per second will always produce the same size file. It would be more accurate to say that an MPEG-1/2 video using X bitrate would look far inferior to the same bitrate on a DivX or XviD file.

The key to quality DivX/XviD is to use multipass. Otherwise it will look pixelated on motion scenes at the low bitrates (700-900kbps) we're talking about. Most high quality DivX/XviD files you get off the net are encoded at around 700-900kbps, and the videos are usually 640x272 or 640x344, depending on their aspect ratio. These numbers are correct. DivX can store video at high res, using bitrates lower than VCD. If you don't want to bother with multipass, then you need to crank up the bitrate to handle the scene changes, fades, and fast motion. Anything above 2000kbps could be considered as very high for Divx/XviD.

If your used to using TMPGenc, then using mpeg-4 compression won't be any slower . It's easiest to create in VirtualDub.

Select the codec you want (xvid, or divx) using the VIDEO | COMPRESSION menu.
Select the DivX or XviD codec.
Click the CONFIGURE button.
Set your encoding mode to "2 Pass - First Pass" for Xvid, or "Multipass - 1st Pass" for Divx.
Confiure any other options (the defaults are typically fine though).
Click OK. Select FILE | SAVE AVI.
Check the option "dont' run this job now", type in the desired filename, and click OK.
Go back to the VIDEO | COMPRESSION menu.
Select the same codec (it should be selected already).
Click the CONFIGURE button.
Change the encoding mode to "2 Pass - 2nd Pass Int" for XviD or "Multipass - Nth Pass' for Divx".
Set the desired filesize or bitrate depending on the codec.
Set any other options (again, not necessary unless you know what your doing), and click OK.
Go back to the FILE menu and select FILE | SAVE AVI again.
Type in the same filename, and again select the checkbox for 'Do not run this job now'.
Click OK. Press F4 for the Job Control screen, or select FILE | JOB CONTROL.
You should see both passes listed. Just press the START button, and let it run. It will perform both passes, and give you an AVI as output.


Try a small sample if you like. Use the Source Range options in VirtualDub to do a small slice of your video. I'd suggest you use the DivX codec for this, since you can't specify kbps with XviD and guessing the size/kbps ratio for a small sample isn't worth the effort. Xvid is geared more towards filling up a CD-R exactly. You'll be amazed at the qualty and low bitrates needed to get them.