Maintaining aspect ratio with ffmpeg transcoding

[zehd]

I've discovered that encoding the MPG at those dimesions is the real slow down.

That why Sub has defaults much smaller that 720x576 or 720x480

Changing the bitrate doens't impact the speed or CPU usage as much as dimensions...

In the program I'm releasing really soon, (I'm documenting, I'm documenting ! ) you can benchmark (sort of) and find the best quality to speed...

@SUMO, what dimensions do you use that gives you the two thirds?

[SuMo]

I'm not to shure what you mean but I quess you want to know what resolutions/aspect ratio's I'm using to get a 2/3 image (without the padding)

My avi's are all around 600 x 256 pixels,give or take 10 pix, does that make any sence ?
I prefer not to size'm down, like 336x.... or something

hmmm as I said , not to sure what you mean by the two thirds dimensions.:o

[zehd]

Oh and for those interested in a preview, I've completed the first part of some documentation explaining my new Post Processing Utility: ZProcess.

You can't download it or install it, (soon though) but a quick look at my page, might give a few more ideas rolled into the final beta release...

I hope it looks like something some of you can use...

http://gbpvr.com/pmwiki/pmwiki.php/Utility/ZProcess

[zehd]

I'm not to shure what you mean but I quess you want to know what resolutions/aspect ratio's I'm using to get a 2/3 image (without the padding)

Yes. I want to know what is the size you actually have in the command line. Did you use my suggestion of: 336x288 ? That's a good starting point. When and if you try my ZProcess, we can start with those numbers...

My avi's are all around 600 x 256 pixels,give or take 10 pix, does that make any sence ?

Yes that makes sense. I understand that you don't want to downsize the quality of the Transcodes. I struggled with this too. Then I realized that a stable system , and high WAF was worth only a little degradation...

I prefer not to size'm down, like 336x.... or something

If you have a powerhouse system, you might be able to get away with a larger format


I hope the webpage I released before I went to bed is enough to keep you going

[zehd]

[ATTACHMENT NOT FOUND]

[SuMo]

@zehd- I've tried the 336x288 dimensions you suggested but the picture was not filling the screen horizontally, it left a black bar on the right side of the screen, so I ended up with the good old 352x288 res.

I changed the padding from 40 to 140, this would give me:

<MVPFFmpegTranscodeCmdLinePAL>-y -i "{SOURCE_FILE}" {SEEK_CMD} -b 2400 -ac 2 -ab 224 -r 25 -s 352x288 -padtop 140 -padbottom 140 -f svcd "{DEST_FILE}"</MVPFFmpegTranscodeCmdLinePAL>

<MVPFFmpegTranscodeCmdLineNTSC>-y -i "{SOURCE_FILE}" {SEEK_CMD} -b 2400 -ac 2 -ab 224 -r 25 -s 352x288 -padtop 140 -padbottom 140 -f svcd "{DEST_FILE}"</MVPFFmpegTranscodeCmdLineNTSC>

The avi I used was 624x256, it looked a bit squished horizontal but centered on teh screen, most avi's are a bit smaller like 604 or something, I guess it would look even better then.
Hope this gives you the info you wanted.

BTW I'm [SIZE="3"]VERRY[/SIZE] impressed by the ZProcess program your developping.... Hope to see a (beta?) release soon !

[tstngry]

- Thanks man! That one works perfectly for me, and I think i figured out why the other ones weren't working for me. I have gbpvr installed to c:\program files\gbpvr without the devnz directory. I changed that in the batch file and it worked great. I did it the way you suggested and started the encoding and played the file after a couple seconds and it was fine except there was the audio delay again. After the encoding was finished tho there was no such problem. It could just be the file that I am encoding from is messed up or something. I was having such good luck with this that I decided to try it without pre-starting the encoding and let gbpvr do it on the fly but it just restarted like before. The only problem I have now is with the video and live tv being croped on the right side, but that is for another day. Thanks for both of your help and I look forward to this process being perfected. Peace.

*Edit* WOW! zehd I just took a look @ your software and it looks amazing! I can't wait to give it a try. If only I could use this for the display of my Live TV too. Keep up the good work! Peace.

[psycik]

How cool, I was just unsubscribing to this thread and saw your screen shot zehd....I'll have to give that a go....

[zehd]

@sumo, well, although I'm still a little confused as to what values you are using as opposed to what are working, it might not matter.

If you're game, we can can try and sort this out with my program. I'll be uploading download and install directions tonight. You should have a chance to play with it within 12 hours from now...

(tick tick tick)

[SuMo]

Sure I'm in, let's give it a try..... that will be a loooooong 12 hours
Or is it 21 hours, since you are in the GMT -8 timezone (and I'm in +1).........

Oh well ... I'm sure ZProcess will give som clarification on dimensions,padding and a lot of other stuff