What s/w do you recommend to compress several recording? (e.g. .mpg to avi)

[mixedup]

This looks promising, haven't tried it myself, though. Feel free to tell us if you find anything that works :-)

Edit: the actual link =)
http://www.videohelp.com/tools?tool=MediaCoder

So I've been trying the MediaCoder 0.3.6, with its default config Mencoder/Xvid. It seems to do the trick fine. Easy to use, you can add whole directories.

End results seems OK'ish, but I've got nothing to compare to.

Only problem is that for a 1 hour show it takes the whole night (: So it must take about 10x (on my 3 year old PC that is) the length of the show to transcode. I guess this is a given that transcoding thaks this long?

[daveid]

yeah your 1.6ghz P4 is not going to make it fly on encoding. however, 10x seems rather sluggish. perhaps you have not enabled turbo-mode in xvid? are you running one pass or two?
for an example i run one pass @ 720kbps bitrate, with GMC + QPEL + smart deinterlacing. my end files (i also compress my audio to vorbis separately after cutting commercials/encoding video) are 120mb for a 21 minute show. it takes approximately 1.5times (30 minutes) for an episode to be completed.
this is with an AMD XP 3000+ cpu. i would imagine yours should not be terribly slower than mine, and i would think 2x original length is where you should be.

[mixedup]

I haven't played with the options even no the main MediaCoder screen. On the video TAB there are:

4 options: "Fixed Bitrate" is choose for me
- Fixed Quantitizer
- Fixed Bitrate
- 2-Pass (on-the-fly)
- 3 Pass (on-the-fly)

There is also a bitrate (high/low quality) selector. Mine is set on the LOWER quality end at 800kbps.

What do you think? I can drop the bitrate however I don't see a 1-pass option like you mention?

[djtaylor]

You mean besides the fact that they require people to RTFM? :eek: Why, nothing at all!

But they don't, it already comes with a c2avi.bat which has enough of a commane line to make it work!

David.

[daveid]

i don't use the same frontend you do, so i have full access to the codec's settings via virtualdubmod. a bitrate of 800 is a little high for tv resolution, i think 720 is on the high side, i used to use 700.. but modifing the bitrate won't make it faster/slower. there is a turbo mode setting in the codecs advanced settings. that makes it much faster of course.

[mixedup]

Hi daveid - sounds worthwhile persueing.

Whats the basic building blocks involved here (to help me understand)? Is it as simple as (I'm totally guessing here):
a) Front End GUI (e.g. MediaCoder)
b) Trasncoder Engine (e.g. Mencoder)
c) Codec support files (e.g. Xvid)

So when you mentioned "turbo mode setting in the codecs advanced settings", which layer is this related to?

What would be the easiest for me, to look under the bonnet of MediaCoder to the lower layers and find/make this adjustment? OR would you recommend dropping MediaCoder and going to virtualdubmod?

[daveid]

all i use is virtualdubmod (it can do mp3 if you download the proper codec for that too, if it is too your liking) and oggdropxpd for my audio. with xvid as the video codec. the turbo mode is in the advanced settings of the xvid codec itself.. virtualdubmod is not difficult to use, i suggest reading the guides at doom9.net for analog-tv capturing & the general vdubmod guide. following the guide for capturing you will find the advanced settings for encoding to xvid. if you choose to use mp3 audio in your encodings, you will need LAME_ACM to do that within virtualdub, it is all outlined in the guides.
i am pickey and i prefer ogg (slightly smaller file, slightly better sound in my opinion) to mp3, so i direct stream copy the audio, extract a wave and compress and mux the ogg back in with my xvid.

[mixedup]

HI daveid - I'm just getting back to this now.

Are you able to post the actual mencoder command line (with options etc) that eventually gets used when you run a transcoding session? I'm interested in the settings (I'm trying to get things working directly with mencoder).

What advantage does virtualdubmod give above & beyond just using mencoder. I went to the virtualdubmod site and it seems quite bare.


Tks

[daveid]

i don't use mencoder.. sorry..
and i have (yet again) changed the way i compress shows..
i capture to mpeg2 (capture card's native format) video & audio
i then demux the streams to elementary m2v (video) and decode the mp2 (audio) to a wav (pcm wave) file using ProjectX - which i also use to cut the commercials (what this does is leaves me with a m2v file and wav, for DVD archiving i compress the wav to ac3 and it's all finished) for mpeg4 (xvid) backups i take the m2v file and create a d2v file with DGIndex. and i compress the audio to ogg vorbis using OggDropXPd.
I then use GordianKnot to compress to xvid in a two pass encoding, finally muxing back in the audio.
This way i can use AviSynth filters such as Tomsmocomp to deinterlace (it is the fastest and best i have found to this date). The interactive work requires about five minutes of my time, while the compression generally takes 2x the length of the show to finish.
so to recap (and it may be too much for a novice to jump into, remember i have been doing video compression for almost six years now) for xvid encodings i use
1. ProjectX - demux streams, decode audio & cut commercials - this also corrects any timestamp errors within the mpeg
2. OggDropXPd - compress wave to ogg vorbis @ 96kbps average bitrate
3. DGIndex - creates d2v file for loading into GordianKnot
4. GordianKnot - creates AviSynth file and automates VirtualDubMod procedures. compressing to xvid 2 pass @ approx. 700kbps. and muxes the final xvid & ogg vorbis into a nice and tidy matroska (mkv) file.
if you want an outline of my specific xvid options i can share those as well.
I use XVID Profile @ Level : Advanced Simple @ L5
Quantization type : MPEG (sharper image)
Quarter Pixel
Global Motion Compensation
B-VOPs
Max consecutive BVOP's: 2
Quantizer Ratio: 1.50
Quantizer offset: 1.00
Packed Bitstream
if animated series i use "Cartoon Mode" found in Zone Options of xvid encoder options
Motion Search Precision: 6 - Ultra High
VHQ Mode - 1 -Mode Decision
Use Chroma Motion
Turbo ;-)
with default quantization restrictions of 1-31...
however, you may not see these options in mencoder, i don't know. this is from the actual xvid encoder options.
i feel almost like i should send you a small sample clip so you can see how my files turn out.. for under 120mb per 20 minute episode, they look pretty snazzy using these options.. and it doesn't take incredibly long either. i'll time the next one (simpsons recording right now, will start compressing it at 6:30 or so and time how long it takes to be completely done)..

[daveid]

alright, so within 10 minutes it's all lined up and the audio is compressed (twice mind you - ogg & ac3), the files for DVD are all finished, and i am just waiting for the video to compress. the first pass goes around 45fps and finishes in approximately 15 minutes. i think the second pass generally goes at around 20fps taking 30 minutes or so to finish (i will update this post in about fifteen minutes when the first pass finishes). this is for a 20 minute episode (no commercials), so i have it ready for DVD & archive (i make the dvds for a couple of friends of mine who don't have cable tv) in under an hours time.
by the way, if you hadn't figured it out by now, i don't generally take the easy route, i like getting my hands dirty...
ok, the second pass started and is going at approximately 30fps and should take 20 minutes to finish.
so add it all up, 10+15+20 = 45 minutes to compress a 20 minute episode to xvid+vorbis & m2v+ac3. and that is why i use the settings i use. it looks very nice (if you want a sample like one minute clip i can probably arrange that somehow it would be ~10mb), and it finishes pretty quick.