Fuzzy picture when converting ISO to AVI

[BassJunkie]

i'm currently trying to convert a 7.7gb iso file to Mpeg-4.[avi] (mencoder) using ffmpegx but i keep getting a fuzzy picture even when the video bitrate is 1400 kbit/s.

Does anyone know how to solve this problem?

[leghorn]

basically, ISO files are images which may contain any type of data. IsoBuster can be very helpful if you want to open them. so maybe you should check out the image file first...

[BassJunkie]

i've already checked it out using vlc and the image is fine.

That isobuster is for windows is there a freeware for macs thats similar?

[guns1inger]

ISO is not a video container - it is a CD or DVD image. Yes, VLC can play them back, but you should extract the content of the ISO to your HDD and encode from there. You are more likely to have success.

[BassJunkie]

Ok i've manged to convert it to better quality but the conversion stops at about 50 min and 720.1 mb, but the process bar doesn't say that the task is complete but it says stuck on 720.1 mb even after leaving it for 30 min..... any idea why?

D-Vision converts the files fine every time but it takes 5 times longer (approx 30 hours for something ffmpegx could do in 5)

[leghorn]

since i'm not into mac software, i dont know about programs working similar to wine (linux). you might use Boot Camp to start Windows virtually (if you have a copy of it). there you can do all the windows stuff, e.g. run IsoBuster to check out the image...

[BassJunkie]

I don't have bootcamp...... i only use freeware

[tomlee59]

You've left out a lot of details (such as the target format -- framerates, codec and resolution -- to say nothing of the source format), so it's hard to offer specific help. For example, you mention only bitrate, but fuzziness is a much stronger function of resolution (think lens focus). Higher resolutions force higher bitrates in order to keep up with motion. So, if by fuzziness you mean that sharpness is unsatisfactory, increase the resolution. And if that produces macroblocking artifacts during motion, crank up the bitrate.

Post back with more specific information, and you'll get more specific help.

And btw, ffmpegx isn't free.

[BassJunkie]

by fuzziness i mean person thats in motion is fuzzy around the body parts in motion, i've already cranked up the bitrate to as much as 11000 and also checked the High Quality button in the options tap & although the picture had more clarity and the fuzziness was still apparent

these are my conversion window i've left everything standard but i do change the bitrate but for this example i left it normal

[Case]

From: VOB
Video: mpeg-2, 720x480, 7000 kbps, 29.97 fps

Your source video is interlaced. I'll bet that is causing the fuzzy moving edges in your (progressive) output. Try the de-interlace image filter.

[tomlee59]

Great -- that's exactly the information folks here will need to help you more.

In addition to the interlace issue that Case refers to, another thing to note is that the source and target resolutions are different. That means that a scaling operation has to take place to convert one into the other. That scaling operation can introduce fuzziness of a sort, and it can be more noticeable during motion than at other times. As you've noticed, simply upping the bitrate hasn't solved your problem. If de-interlacing doesn't take care of what you're objecting to, read on. Otherwise, ignore.

I recommend using D-Vision 3 for this particular task. Since you are obviously seeking the highest quality, using D-Vision's 2-pass transcoder at the maximum quality setting will give you the best results that XviD/DivX can provide. Quality takes time, of course, so be prepared for a bit of a wait. Experiment first on small pieces to find bitrate and other settings that work to your satisfaction. Then convert the whole thing.

It's also important to set expectations appropriately. You are converting from one type of video into another, so there will be degradation. It is simply unavoidable. If your expectation is for the output to look exactly as good as the source video, that's unrealistic.

[BassJunkie]

thanx Case, i will try that to see if it works in the next few days because i haven't got enough time today.

@tomlee59: D-vision is great for small files on my mac but for a 7.2gb DVD it will honestly take me over 30 hours on my Mac OS X 1.25 GHz PowerPC G4 10.4.9..... but thanx for the suggestion.

I'll let you know in the next few days if i manged to solve the fuzziness problem by de-interlacing the file.

Thanx

[tomlee59]

@tomlee59: D-vision is great for small files on my mac but for a 7.2gb DVD it will honestly take me over 30 hours on my Mac OS X 1.25 GHz PowerPC G4 10.4.9.....

That sounds unusually excessive -- on my 800MHz G4 TiBook, D-Vision easily converts a full DVD overnight. Are you running some other compute-intensive tasks at the same time? How full is your hard disk? Are you strapped for RAM? In 30 hours, I can transcode into h264, so DivX/XviD should be a snap on your much-faster Mac.

[BassJunkie]

i've usually got about 30gb MD space or less, which could be the problem abd am usually only running the internet while converting..... i don't know how to check my RAM on my OS X, does anyone know how and what would be a healthy ram and HD Space on my os x to get better conversion speed?

The converting is fine now i have checked the de-interlacing button and that has done the trick, now could you help on getting a high quality picture without excessively increasing the file size, (i hate to admit it but i have watched pirated movies on the net and they manage to fit a 120min movie in 700mb without compromising the quality.... how can i do this using ffmpegx?

[guns1inger]

. . . . . and they manage to fit a 120min movie in 700mb without compromising the quality.... how can i do this using ffmpegx?

They can't, with ffmpeg or anything else. Major compromises are made to resolution and quality.

[tomlee59]

As guns1inger says, you can't compress that much without compromise. You may think that the downloaded videos are able to compress without compromising quality, but you're making that assertion without actually comparing the source file to the output. What you're really saying is, "The result looks good to me." That's a different statement. If you were to do the comparison, you would see that there is indeed a difference!

To reduce the quality loss, you can use more advanced codecs; h.264 provides better quality at a given bitrate than XviD, which in turn does better than MPEG2, which does better than ... you get the idea. The drawback is that compression (and decompression, for that matter) are progressively more computationally intensive, so encode times streeeeeetch out, and you need more substantial hardware to enable playback.

If filesize matters more to you than quality, then use one of those codecs. If playback on a wide variety of platforms is important and/or you want to preserve the quality of the original, don't.

[BassJunkie]

Is h.264 a mp4 format, if so than i want to keep it as Xvid/DivX.

Could you also tell me how to convert a 150min video to fit onto a 700mb cd?

[guns1inger]

150 minutes into 700 MB will require either a very low resolution (512 x nnn) or a low bitrate (509 kbps with 128 kbps MP3 audio). Neither or which are going to give you good quality. 90 - 100 minutes is about the max for reasonable quality it that space.

I don't understand why you are imposing an arbitrary 700 MB limit on your encoding. If you want to get into "the scene" and offer pirated video, then you should talk to pirates about how to encode. But if this is for your own enjoyment, encode for quality. Burn to DVD and you can still fit a lot on, and get decent quality. I encode SD digital broadcasts to Xvid with 128 kbps MP3 audio at a resolution of 640 x 368 at around 10 MB/min of footage, and get nice, clean images. Yes, I can't quite fit as much on a disc as encoding them at an artificially low filesize like 350 MB, but I can watch them without cringing at the blocking and other artifacts caused by squeezing the crap out them for no good reason.

[BassJunkie]

No i'm not tying to get into pirating game, lol. I just want to fit my long home videos onto a cheaper 700mb disc.

I've got all the information i need now, thanx to all the guys who helped & have a great day.. bye

[jagabo]

Home videos will not compress well unless you are using a very high quality camcorder, lots of light, and shoot at 24 (NTSC) or 25 (PAL) fps progressive. Shaky, noisy, interlaced video will not compress well. All that shaking and noise are the enemy of compression.

Fitting 150 minutes into 700 MB is simple:

file size = bitrate * running time.

So to reduce the file size use a lower bitrate. Use a bitrate calculator to determine the birates for audio and video. But 150 minutes of home video is going to look like crap at 700 MB. You can reduce the resolution to get fewer macroblock artifacts. But resolution is a part of quality.

[tomlee59]

Since quality is in the eye of the beholder, you are the only one who can decide whether the result looks good to you. Experimentation is the only way to find that out. Take a short segment of the video you want to convert, and simply try a variety of codecs and settings. This will let you get calibrated on what the resulting quality is, and also as to how long the conversions take. If you find something that meets your personal standards of "good enough," then use that.

If your main desire is to cram a movie onto a single CD (without requiring compatibility with standalone players), then you must be willing to sacrifice quality. Since you've already said that the stuff you've downloaded looks ok to you, then maybe an acceptable tradeoff is possible in at least some circumstances. My personal recommendation is to use D-Vision, because it does a pretty good job of figuring out settings for you automatically. You can override the choices it makes, but most of the time you'll probably just go with what it selects.

Just try a bunch of stuff yourself, and you can decide what works for you.