ffmpeg help - 16:9 HD -> 4:3 SD

[zehd]

Well just to tease a little bit more, here's the status...

I have ZProcess Downsizing and cropping center cut for several different dvr-ms dimensions. It is nearly real-time. My computers aren't nearly grunty enough to do on the fly transcoding, but yours might...

The new ffmpeg is magic. I will want the version that has all the codecs in it though.

Right now, I'm defining the first set of defaults that should be used to start with. As I know you haven't worked with ZProcess much, you may be lost using it. The idea behind it is that you don't have to configure it. It should just work, straight off.

I won't bother working with MEncoder yet. I'll be letting you have a preview tomorrow. We can shake some bugs out, or write some docs for it then...

[Braklet]

I have ZProcess Downsizing and cropping center cut for several different dvr-ms dimensions. It is nearly real-time. My computers aren't nearly grunty enough to do on the fly transcoding, but yours might...

Haven't tried R/T video transcoding, although my HTPC has served multiple transcoded audio feeds simultaneously (through SlimServer).

The new ffmpeg is magic. I will want the version that has all the codecs in it though.

Check your forum PMs. One thing I preferred with the new ffmpeg is that the video and audio bitrate scales are now equal. Maybe I'm just dumb, but that bugged me about the previous ffmpeg.

As I know you haven't worked with ZProcess much, you may be lost using it. The idea behind it is that you don't have to configure it. It should just work, straight off.

Yes, that is true. I might need a little hand holding to start off. But I'm a quick learner.

[Braklet]

I purchased videoredo a couple years ago and it added my registration number to the beta showing me as a registered user. They also offer a 15 day free trial.

My registration upgrade to VRD TVSuite didn't seem to "take" until the 3rd try. Strange since it pulled all my reg info out of the registry correctly.

Anyway, I am giving the DVD authoring tool a try. Thus far I am very enthusiastic. It seems super easy to use, definitely less hassle than DVDLab-Studio (although much less powerful).

The really great thing is that it made cropping that Survivor episode and downcoding it to lesser bitrate almost trivial. Of course, it is also taking some 45 minutes to do the recode step.

I wish I could use video frames as DVD menu buttons, but that is a small price to pay for the sheer ease of archiving to DVD Video.

[zehd]

Check your forum PMs. One thing I preferred with the new ffmpeg is that the video and audio bitrate scales are now equal.

So that's why I had trouble... I was unable to specify the audio bitrate. What do you mean, same scale? Gimme an example of -ab 192 <<< this errors

Left blank it defaults to 64 k... Do you mean I need to use the 'k'...?

[Braklet]

What do you mean, same scale? Gimme an example of -ab 192

-ab 192000

Just like -b.

The previous method (-b = scale 1, -ab = scale 1000) drove me nuts until I figured it out, but I much prefer it when -b and -ab use the same scale.

[pvruser]

i have a similar issue... just got a dual core e2180 a few days ago so i want to save hard drive space now

here's what i got, it works for experiments but didnt implement it yet:

ffmpeg.exe -y -i "sample.mpg" -b 4000k -ac 2 -ab 128k -r 29.97 -s 1184x480 -f svcd -cropleft 240 -cropright 240 -aspect 4:3 -threads 8 "test1.mpg"

i know it's odd to have -s 1184x480 but thats the only thing that works.

my sample is 1080i (1920x1080). still have to test it on a 720p but i assume it wont work (crop & total sizes need recalculated).

oh and i got the latest ffmpeg from here:
http://ffdshow.faireal.net/mirror/ffmpeg/

hope this helps... i'm also planning to refine this and use it in my postprocessing scripts.

[pvruser]

oh here's how to remove the ugly closed captioning thingy from the top:

ffmpeg.exe -y -i "sample.mpg" -b 4000k -ac 2 -ab 128k -r 29.97 -s 1184x500 -f svcd -cropleft 240 -cropright 240 -croptop 20 -aspect 4:3 -threads 8 "test1.mpg"

20 lines on top are cut but also added to the -s. the final size is 704x480 - same as the ones i got from normal SD channels. not sure if 704 or 720 is correct but it sure looks right in my bsplayer

[zehd]

I'll branch off this thread to the ZProcess sub forum, regarding the new beta that will try to automate CenterCut

http://forums.nextpvr.com/showthread.php?t=29765

[pvruser]

ok i'm annoying but i just played with a file that had dropped frames (bad reception duh)... well audio got out of sync so i added -async 15 like this:

ffmpeg.exe -y -i "sample.mpg" -b 4000k -ac 2 -ab 128k -r 29.97 -s 1184x500 -f svcd -cropleft 240 -cropright 240 -croptop 20 -aspect 4:3 -async 15 -threads 8 "test1.mpg"

i guess i cant think of anything else for now

[pvruser]

1080i:
ffmpeg.exe -y -i "sa1.mpg" -b 4000k -ab 128k -r 29.97 -s 1184x500 -f svcd -cropleft 240 -cropright 240 -croptop 20 -aspect 4:3 -async 15 -threads 8 "test1.mpg"

720p:
ffmpeg.exe -y -i "sa2.mpg" -b 4000k -ab 128k -r 29.97 -s 1024x490 -f svcd -cropleft 160 -cropright 160 -croptop 10 -aspect 4:3 -async 15 -threads 8 "test2.mpg"

this transcodes fine to 704x480 and also supports mono (-ac 2 makes a mess if program is mono so i removed it)