Film captured (Huffyuv), now how to convert it to DivX?

[misi2096]

Hi to all out there!

I'have the following question: I've captured a film in huffyuv that of course is a really huge file. Anyway. How can it be converted to a DivX or XviD file that is in a DVD quality but is not bigger than one CD (700MB)?

I'mean, the films that can be downloaded from the file-sharing-networks are at an excellent (of course releated to their size!) quality, but if I try to convert my videos they just don't get good enough.

I encode my films in 2 passes or in Nth pass but still not getting the expected result. As i analyze movies from the internet, they have a very low (aprox. 700-800kbps) bitrate. Question: are these files encoded more than 50 times ???????? [sorry] Or there is another trick these guys use?

I would welcome any idea!

Thank you in advance!

Michael

[Cornucopia]

Here's the trick: most of those DivX that you see on the net are probably DivX converted from DVD rips. That is, the original "capping" was done by the Hollywood studio with the original film resolution (2k, 4k, etc) on Rank-type telecine. In contrast, you are capping a "film" (probably a video of a film--at least 2nd generation down already), using consumer/prosumer grade cards. You have more things to contend with: Increased Noise, Less Colorspace resolution, telecine Judder, consumer A-to-D nonlinearities. If you're capping your own home movies, you also have to deal with: Camera shake, non-optimal ("poor") lighting, consumer camera lens & chip irregularities, etc.

In the best of all worlds, encoding/compressing should be done once (at the very end, before authoring and burning). Yes, you can get increased Quality-per-Bitrate if doing a VBR encoding using a multipass process, but there is a law of diminishing returns, and for most purposes, 2pass is as good as you need. Now--just to make sure you understand--that's 2-passes (evaluation+compression) of the file for 1 encoding, not encoding twice.

Scott

[junkmalle]

Most of the really good Divx/Xvid files are DVD rips. They are starting out with very clean video so it compresses much better than a off-air or VHS recordings.

Frame size is also an issue. You rarely see 640x480 divx files online. You're more likely to see 512x384 or smaller for 4:3 material, and the equivalent width with smaller height for wide screen material (512x240 for example). The smaller the frame size, the farther your bits go.

Going beyond 2-pass won't get you much more quality.

You might try some spacial and temporal filtering.

[misi2096]

Yes I know that these movies are DVD rips, but it seems to me that the picture of the capped huffyuv is neither checked, so what (expcept the colors and so) difference does it make? Or do you wan to say that I can forget that I could make such a good quality film from my home caps?

misi2096

[SaSi]

Depending on the quality of the media/source you capped and the quality of the capture device (I guess it is a VGA with Video in or something similar) and the experience you have in capturing, you can get from bad to descent to acceptable results.

To answer your question:
All you really need to do is open the huge hufyuv AVI with VirtualDUB and save it as AVI using the appropriate codec.

For video, you obviously want to save it to DivX. (Do you have it installed?). Select Video --> Full Processing Mode and then Video --> Compression and then DivX from the menu.

For audio, you also need a compression codec, otherwise you get almost 700Mb for one hour of audio. Some sort of audio MP3 codec is a good choice. (Do you have them installed?)
Go to Audio --> Full Processing Mode
Audio --> Compression and select the appropriate MP3 codec from there.

Now, the trick is in the configuration of the codecs and the frame size.

You can hardly fit one hour of DVD quality on a CD using a Full DVD frame size (720x480/576). Typically you need to resize the frame to something smaller. Quarter frame is a good start. To do that you select a VirtualDUB filter to resize the video down to any frame size you want.

For DivX, you need the best possible compression for a given file size. So, you need to select the bitrate required to fit the duration of the video onto, say, 700Mb - leaving ~50Mb for audio. Select two passes for better quality.

For audio, you need to both decide if you are going to downsample the track from whatever sample size and frequency you captured (e.g. 48000kHz 16bits) to something smaller if the video is too long.
Next decision is the bitrate. I would choose 129kbps joint stereo.

Now, if the above sound too complicated, check the guides section. Plenty of step-by-step guides for most of the above issues.

[SatStorm]

Use autoGK to convert your avi to dvix / xvid

[misi2096]

Depending on the quality of the media/source you capped and the quality of the capture device (I guess it is a VGA with Video in or something similar) and the experience you have in capturing, you can get from bad to descent to acceptable results.

To answer your question:
All you really need to do is open the huge hufyuv AVI with VirtualDUB and save it as AVI using the appropriate codec.

For video, you obviously want to save it to DivX. (Do you have it installed?). Select Video --> Full Processing Mode and then Video --> Compression and then DivX from the menu.

For audio, you also need a compression codec, otherwise you get almost 700Mb for one hour of audio. Some sort of audio MP3 codec is a good choice. (Do you have them installed?)
Go to Audio --> Full Processing Mode
Audio --> Compression and select the appropriate MP3 codec from there.

Now, the trick is in the configuration of the codecs and the frame size.

You can hardly fit one hour of DVD quality on a CD using a Full DVD frame size (720x480/576). Typically you need to resize the frame to something smaller. Quarter frame is a good start. To do that you select a VirtualDUB filter to resize the video down to any frame size you want.

For DivX, you need the best possible compression for a given file size. So, you need to select the bitrate required to fit the duration of the video onto, say, 700Mb - leaving ~50Mb for audio. Select two passes for better quality.

For audio, you need to both decide if you are going to downsample the track from whatever sample size and frequency you captured (e.g. 48000kHz 16bits) to something smaller if the video is too long.
Next decision is the bitrate. I would choose 129kbps joint stereo.

Now, if the above sound too complicated, check the guides section. Plenty of step-by-step guides for most of the above issues.

Ok, thank you. I understood everything

But in the meanwhile another question appeared:
When I try to cap(Lifeview Flyvideo 3000) a video copmressing the sound with the mp3 codec I allways get a video without any sound. I just don't get it. What could be the reason? I've tried to use an Ogg Vorbis codec but the copmuter allwas crachses at the beginning of the capping.

Thank you in advance!

misi2096

[SaSi]

Don't use audio compression during capturing. Most encoders need to "browse" throught the audio to increase their efficiency and this is just impossible for on-the-fly encoding.

Use PCM audio (~600Mb / hour) and encode it to whatever when the video is done with editing. It helps avoid the various "audio out of sync" problems also.

[misi2096]

Thank you guys! Unfortunately I solved the problem:
The trick is that I cap to an 200GB ATA HDD through USB2 and not to the main HDD that is in the PC. I don't really understand why, but if I capture onto the internal HDD (also 200GB but SATA) it seems to make difficulties for the PC.
Anyway, yesterday I capped a film (1:48:00) with huffyuv and PCM sound and I lost only 7 frames during the whole process, which is an absolute highscore for me

Now I'll use VirtualDub for edit and something to encode the 38,9GB film into a DVD, because in fact we are living in the XXI.th century and for home useage it's better to make DVDs instead DivX.

misi2096

[junkmalle]

I don't really understand why, but if I capture onto the internal HDD (also 200GB but SATA) it seems to make difficulties for the PC.

That's very common. Just about every capturing guide recommends you capture to a different physical drive than the one the O/S is on. Even when you're not doing anything Windows will occasionally read/write to the boot drive. If this happens while you're capturing it leads to dropped frames as the drive heads have to seek around the drive.