Dad

Originally Posted by PocketTV Team

It's no different: If the quality of your DivX or MPEG is *very* good, you can convert it back to DVD. Assuming DVD is about 4 Mbps, you need to make your DivX at 2.5 to 3 Mbps, and your MPEG-1 at about 4Mbps, if you want to be able to convert back to DVD (MPEG-2) at 4Mbps with absolutely no loss of quality compared to the original. Naturally it depends on the encoders that you use.

Thanks - I've since discovered that I can just burn MPEG files direct to CD/DVD and play those on my DVD player, my DVD player dopesn't support DivX files and they need to be re-encoded which takes time and has a significant quality loss. Keeping them in MPEG format means I can use them on all devices I currently have incuding my PDA.

PocketTV Team

Since you asked video encoded in MPEG with no gamma correction (i.e. darker), I have added the following files:

http://www.pockettv.com/mpg/vga/5e-6...-v3-darker.mpg (1.7 Mbps)
http://www.pockettv.com/mpg/vga/5e-6...-v3-darker.mpg (1.2 Mbps)

and also this one, with gamma correction:

http://www.pockettv.com/mpg/vga/5e-6...1.2Mbps-v3.mpg (1.2 Mbps)

MX30user

Um, this is turning into a flame war so to speak.....anywya, i don't remember what program i did it with, but i got a movie to fit onto a 128 mb sd card, but it wasn't very good quality, but it still was watchable, and it worked for me.

__________________
X30-1gb/128mb SD card
In the middle of buying laptop :rolling:

Dad

Originally Posted by MX30user

i don't remember what program i did it with, but i got a movie to fit onto a 128 mb sd card, but it wasn't very good quality, but it still was watchable, and it worked for me.

I have divx'd all the kids animated moves i have down to 128mb using pocketdvd studio so that i can have a collection with me for long trips. I only do it in mono sound, 15fps - which is more than enough to keep them entertained when required - this is one of the cases where quantity and variety certainly outweigh the need for quality

PocketTV Team

> Um, this is turning into a flame war so to speak.

Yes. This thread was only to discuss how to make high quality VGA-res MPEG-1.

I did not want to get into the discussion about other codecs that are more efficient than MPEG-1, but some people brought-up the subject.

I could also say that WMV 10 is more efficient than Xvid/Divx, since it is similar to H.264 (Xvid/Divx are based on earlier versions of MPEG-4 and are slightly less efficient).

Again, the point of this particular thread was not to compare all the video codecs. Please post in this thread only if you are interested in making high-quality VGA-res MPEG-1. Thanks.

Enragin_Angel

Actually, when you install too many MPEG-4 decoders, they sort of "fight" with each other. FFDShow Alpha (Oct. 2004) actually takes over decoding for all codecs, but sometimes the other codecs will still try to decode it. If you were able to watch it ok before and now not able to watch it, it means you've installed too many decoder filters.

PocketTV Team

Originally Posted by Enragin_Angel

Actually, when you install too many MPEG-4 decoders, they sort of "fight" with each other. FFDShow Alpha (Oct. 2004) actually takes over decoding for all codecs, but sometimes the other codecs will still try to decode it. If you were able to watch it ok before and now not able to watch it, it means you've installed too many decoder filters.

No, I have never been able to watch this one at the right speed on the desktop.

The only other DivX decoder I have installed is DivX Player 2.6 (which cannot play this file, BTW).

The file plays fine with Betaplayer.

victorypoint

Originally Posted by PocketTV Team

>Please post in this thread only if you are interested in making high-quality VGA-res MPEG-1. Thanks.

Sure, I'd like to give your method a go. Do you provide a TMPGenc profile or is it a bit more complicated?

-AJ

PocketTV Team

It's a bit more complicated, but still manageable.

We use DGIndex (part of the DGMPGDec package) to do the inverse telecine index and to convert the ACC audio from the vob into a wave file. I used DGMPGDec 1.2.1 from http://www.videohelp.com/tools?tool=622 .

Then we use tMPGEnc 2.524 (from www.tmpgenc.net) for the encoding, using the .d2v index file as the video source, and the wav file as the audio source.

I found the best quality is obtained using the rate-control mode CQ_VBR with Quality set to 9 and Maximum bitrate set to 2000 (Minimum set to 0). In general this get VGA at an average bitrate of about 1.4 to 1.7 Mbps (including 64 Kbps audio), with very good quality. Always use "Highest quality" motion search if your PC is fast enought, or "Motion estimate" otherwise. The CQ_VBR parameters can be adjusted, e.g. Quality set to 8 and Maximum bitrate set to 1200 will get you VGA at 1.0 to 1.2 Mbps.

Now, there is one small issue when using VBR: the video is encoded with variable bitrate and the audio is fixed bitrate, so the audio and the video packets can (sometimes) get very far apart in the multiplexed stream. I have not tested what happens with the various players (including Betaplayer and PocketTV) when the audio and video packets become VERY far apart, but this could cause problems if the distance between them is larger than the buffer size. This is something we are looking at. On small clips, or contents which is more or less homogenous in complexity, it should not be a problem.

Unfortunately, for some reason I cannot read AVISynth source with tMPGEnc (i.e. using .avs scripts). Not sure why. Luckily tMPGEnc can read .d2v index files!

DGIndex does a very good job at inverse-telecine. I was never able to get correct inverse-telecine results with the (very complex) inverse-telecine feature buitt in tMPGEnc.

To do it with DGIndex: Start DGIndex.exe, load the .vob files with File > Open. Select Video > Field Operation > Forced FILM. Select Audio > Output Method > Decode to WAV. Select Audio > 48 -> 44.1Khz > Mid to convert audio to 44.1 Khz (it's important, because the Pocket PC audio drivers are less efficients when dealing with 48 KHz audio, they use more CPU cycles). You can select the Audio conversion quality, but higher quality will make the DGIndex process slower. Then select File > Save Project, and DGIndex will generale the .d2v index file and the .vaw audio file that you will encode with tMPGEng.

Other interesting tMPGEng settings that work:

Setting > Advanced > Noise Reduction works well by removing spacial and temporal noise. The "high quality mode" of the filter is very slow and may not be that important.

The Setting > Advanced > Sharpen Edge works well by increasing subjective quality. I use settings Horizontal 64, Vertical 64.

If necessary, Setting > Advanced > Custom Color Correction can be used to adjust the gamma etc.

To set the parameters of eacj of those advanced settings, bouble-cluck on the setting in the list Setting > Advanced, and make sure the check box is selected to enable it.

A small detail not to forget: very often, audio from DVD must be normalized, otherwise the level is loo low. tMPGEnc does that very well and automatically: In Settings > Advanced > Audio, check "use audio edits" and click on "Setting". Then check "Change Volume" and click on "Normalize". Type 100, click OK, and when the audio has been analyzed, the normalization factor will be set for you. Click OK to close the audio settings. Generally I encode the audio at 64 Kbps in stereo or joint-stereo, but you can select a slightly higher bitrate if you have very good ears and very good earphones.

victorypoint

Can you give us some details on how you're ripping and demuxing the VOB?

-AJ

PocketTV Team

Originally Posted by victorypoint

Can you give us some details on how you're ripping and demuxing the VOB?

Well I don't want to give advices on how to rip DVD's, because even if it is your own DVD's and you just want to watch the content yourself, and not share it on the web, it could be be illegal in some countries, like the US, because they have laws making it illegal to decrypt or work around copy-protection schemes. No-one has been put in jail for ripping their own DVD's, but still, some people like the DeCSS author got in hot water.

There are some excellent tools like SmartRipper that are very easy to use and that extract the vob files from a DVD completely automatically.

The Demultiplexing of the .vob files is done by DGIndex. In fact, DGIndex generates an index file that tells the encoder where the frames are located in the file, and it extracts and convert the AAC audio into WAV, a format the tMPGEnc can use. I don't think it is necessary to install AVISynth to do what I described, but I did install it, too.

PocketTV Team

There are lots of guides about using SmartRipper. One thing to remember is that DGIndex used to be called DVD2AVI.

Check out http://www.afterdawn.com/guides/arch...vi_tmpgenc.cfm . It's a guide for converting DVD to VCD (MPEG-1), so it is quite close from what we do, except for the resolution (VGA) and Rate Control (VBR).

victorypoint

Originally Posted by PocketTV Team

There are lots of guides about using SmartRipper.

I understand your concern about legality. I use DVDDecrypter and just want to confirm which options to turn on/off when ripping the VOB. It can demux the VOB to M2V and AC3 as well but your recommending to use DGIndex instead?

Originally Posted by PocketTV Team

One thing to remember is that DGIndex used to be called DVD2AVI.

I did not know that. Thanks.

-AJ

PocketTV Team

Originally Posted by victorypoint

I understand your concern about legality. I use DVDDecrypter and just want to confirm which options to turn on/off when ripping the VOB. It can demux the VOB to M2V and AC3 as well but your recommending to use DGIndex instead?

The question is: does DVDDecrypter do inverse-telecine ?

i.e. if your DVD is NTSC using 3:2 pull-down, does the index refers to the original movie frames, or just the interlaced frames on the DVD.

For best performances, it is very important to code the movie frames (progressive).

Arthur Pendrag

Can someone tell me the best way to fit an entire DVD (about a 1.5 hour average I suppose) onto a 256 sd card? Should I go for VGA res or a lower res so it will be better video quality? I recently compressed Black Hawk Down to 256 mb with Fairuse and it had ok quality. I think it was a lower resolution but then again I am not sure if Beta-player was running at VGA. Is there a tweak you have to get or anything? Well lots of qustions but most importantly I just want to know what the best settings/code/resolution to use to compress a DVD to 256megs.