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View Full Version : 4:3 letterbox --> 16:9 anamorphic -- crop/resize without re-encoding/transcoding?


Red Right Hand
4th June 2004, 17:30
I couldn't decide which sub-forum to post this question in, but, since part of my question does deal with DVD Rebuilder, I finally decided on this one.

Until recently, the extent of my "DVD (re-)authoring" experience has been with 1:1 backup (transcoder) applications like DVDShrink, Nero Recode, CloneDVD, etc. Yesterday, I downloaded DVD Rebuilder, along with AviSynth and the QuEnc and ReJig encoders. I realize that using a utility like Rebuilder greatly simplifies working with AVS scripts, etc., but it's still a big step for me, and fairly confusing.

I am not really interested in learning all of the ins and outs of DVD authoring, as far as being able to edit .VOB and .IFO files to change menu structures or streams, etc. The idea of just learning how to write and execute my own AVS scripts is daunting for me, and I just don't really have the time or energy to tackle this kind of project, although I'm amazed at what other people (posters at this forum, and the authors of all these DVD-editing utilities) have been able to do.

I have what seems to my uneducated mind to be a fairly simple task that I want to accomplish. I have some older DVD movies which are encoded as letterboxed 4:3. In other words, the actual MPEG includes the black bars at the top and bottom of the 4:3 image as part of the video file. I have a 16:9 widescreen television, and I would like to convert these movies to true 16:9 anamorphic widescreen format.

I have been successful in this conversion using a couple of different methods. One was to use DVD Rebuilder (with either QuEnc or ReJig) to transcode the DVD files. It does work fine this way -- all I do is turn on the "Convert from LB4:3 to 16:9" option. It was such a smart idea to include this one-click conversion option in Rebuilder -- I am grateful to have found this utility for this reason. The only frustration I have with the process is that it takes a very long time -- a matter of several hours -- to complete the transcoding/rebuilding process.

I've also been successful using FlasKMPEG to do the cropping/conversion, but it also involves transcoding and takes just as long if not longer than Rebuilder to do the job.

So, finally, here's my question. All of the discs that I'm trying to do this 4:3 letterboxed to 16:9 anamorphic conversion with are DVD-5's, not DVD-9's, so I don't really need the data compressed/transcoded. Is there a way I can just crop/resize the existing data without having to re-encode it all? Is there any faster way to do this conversion than having to use a transcoder this way? I just don't know enough about MPEG encoding to know the answer to this question.

Thanks!

Rombaldi
4th June 2004, 17:41
sorry, the only way to go 4:3 > 16:9 IS transcoding... no shortcuts...

Red Right Hand
4th June 2004, 18:05
Is there a faster way to do this crop/transcode process, then? Just out of curiosity, I used DVDShrink to transcode one of these DVD-5 discs, and it took just over 30 minutes, with no noticeable loss of video quality. Unfortunately, though, DVDShrink (nor Nero Recode, CloneDVD, etc.) can do the 4:3 --> 16:9 conversion

Since the video doesn't have to be compressed -- it is already small enough to fit on a blank DVD-R as is -- is there a faster way to recode? DVDRebuilder takes a minimum of 4-5 hours any way I try it.

Joergen
4th June 2004, 18:23
Rombaldi used the wrong word.. the only way to morph the image in any way is ENCODING. Transcoding can only take the image as-is and drop its bitrate.

Red Right Hand
4th June 2004, 18:28
Thank you for this clarification, Joergen. I was never clear on the distiction between encoding vs. transcoding, but you've made that very clear to someone who knows very little about it. I now see why transcoders like DVDShrink can work so much more quickly than if they actually had to re-encode the entire stream.

Rombaldi
4th June 2004, 18:46
Originally posted by Joergen
Rombaldi used the wrong word.. the only way to morph the image in any way is ENCODING. Transcoding can only take the image as-is and drop its bitrate.

OOps... I stand (er.. sit) corrected...