is tmpeg that slow??

[HalfHuman]

i never did a mpeg4 to mpeg2 conversion because it isn't worth it (in my case)
i have a question though. a friend said that doing a conversion from mpeg4(divx, xvid) to mpeg2 is much slower than encoding from mpeg2 to xvid for example. for example a 2 hour movie compressed to xvid is done realtime (>30fps) but using tmpeg to do a xvid to mpeg2 takes 6 hours. how could that be explained? i know that mpeg4 compression is far more demanding in processing power compared to mpeg2.
another question is: is resizing the image worth when doing an xvid to mpeg2 encode?

[HalfHuman]

guess nobody has a clue.
can't anybody answer?

[SiXXGuNNZ]

I dont know about tmpgenc

but xvid I avg 35 fps per pass on a 2pass encode

with cce I avg 85 fps per pass on a 2pass encode

xvid is my mpeg4 and cce is my mpeg2

[HalfHuman]

i thought so
maybe he has many filters in the postprocessing stage

[Paulcat]

I have a few tv shows in Xvid/MP3 format and convert them to MPEG-1 (VCD) to watch on my set top player.

To make a standard MPEG-1 (352x240) for a 50 minute tv show takes about 90-100 minutes on my PC (Athlon XP 1900+, 768 MB DDR Ram). The only operations being done are re-sizing the video and re-encoding the audio (the absolute minimum).

Adding a cropping filter or a noise reduction filter will drag the encoding time to 130 to 150 minutes.

A 50 minute show has close to 72,000 individual frames that need adjustment!

If the show is captured at 352x240, then converting is close to real time in TMPGEnc

[HalfHuman]

:confused:
any more oppinions?
seems to me that tmpeg is far more slow than cce (from what paulcat and sixxgunzz said) and of course than xvid or divx.

[Paulcat]

Just noticed the 2nd question, if you are making a STANDARD mpeg2 (or mpeg1) file, then they are STANDARD sizes, resizing is not really an option unless your mpeg4 file is already one of these sizes.

This all really depends as well on why you'd want to do any of this. If you have an mpeg4 video and tv out on your video card, then you can probably leave the files as they are.

If you want to "save space" and have decent image quality AND keep the files on your PC, then sure, encode them to mpeg4, otherwise, why bother?

And likely the reason mpeg2 (DVD) to mpeg4 is faster is that you don't need to resize anything..

[HalfHuman]

resizing is not something that requires a lot of processig power
i don't buy that. can't be that.

[Rickkins]

Ridiculously slow. I did a tv capture, using virtualvcr/Pic Video MJPEG codec.

Came out to about 20gigs.

For me to encode it into a dvd compliant mpegII file it says 22 hrs.
And I don't even see a way to save it at a certain point so I can shut the machine down overnight and start again in the morning.

What a joke.

[Dreamhacker]

TMPGEnc seems pretty slow, but it depends on quality I think. What takes 30 minutes from XviD to MPEG-2 in NeroVision Express, uses 2 hours in TMPGEnc...But then I can get much better quality in TMPGEnc

[Paulcat]

Just yesterday I had to use VirtualDubMod to convert an mpeg2 (.m2v) file to avi (xvid), the running time was 25 minutes and the conversion took just under an hour from mpeg2 to avi (no audio, no filters, no nothing, 1 pass highest quality)

(I had to do this as tmpgenc did not open this particular m2v file, why I don't know. (I'm doing a PAL to NTSC conversion))

Now I'm converting the file back to mpg2 (.mpg) to be able to make a dvd and the conversion back will take about 1 hour and 45 minutes (with resizing and no other filters at a bitrate of 6400 kbps)

I don't know how you got a framerate of 30fps converting to xvig, I think I peaked at 11 or 12...

[HalfHuman]

let's not mess up the notions
mpeg2=codec
avi=container
compression speed from raw video or mpeg2 to xvid depends on the resolution and the quality: gmc, qpel etc. at 640x... 11 or 12 tops is very slow. maybe you used a 720x... movie. i have a duron 1600 and it works at 20 fps at highest quality setting (maybe lower).
note that i compress usig resizing with avisynth.
i believe that guys working on tmpeg should do something about speed.

[Paulcat]

Originally posted by HalfHuman
let's not mess up the notions
mpeg2=codec
avi=container
compression speed from raw video or mpeg2 to xvid depends on the resolution and the quality: gmc, qpel etc. at 640x... 11 or 12 tops is very slow. maybe you used a 720x... movie. i have a duron 1600 and it works at 20 fps at highest quality setting (maybe lower).
note that i compress usig resizing with avisynth.
i believe that guys working on tmpeg should do something about speed.

I should have written from mpeg2 to mpeg4, it was a long week!

The original video was widescreen PAL dvd video. Since I knew I had to go back to mpeg2 after, I wanted the highest quality mpeg4 I could get without going fully uncompressed (small hard drive). Basically I wanted to change the "format" of the video rather than do any processing of it.

Are there standards to .m2v that allow players to recognize it and yet be different enough internally that some can be edited and some not?

[drcl]

please explain what u mean by format, paulcat.

[Paulcat]

All I wanted to do was crop it to fit the NTSC DVD standard.

Since then, I have found more ways to speed up TMPGEnc, I can do a 50 minute avi tv episode to VCD in just over an hour now. In Environmental Settings, in the VFAPI tab, only select the plug-in that allows you to open the file, de-select ALL the others, and TMPGEnc will run MUCH faster.