Lots of Original MPGs. What should i convert them to?

[neoskunk]

As the title says I have a bunch of the original MPGs off some dvds but they take up between 3 and 7 GB a piece. I know I can use AutoGK and make AVI files but I was wondering if there are any other good movie types to convert to?

Only requirements being:

good quality
decent compression
can stream to xbox via windows media center

[Blue_MiSfit]

When folks re-encode convert DVD content (MPEG-2), and store the result in an AVI container, this usually uses Xvid or DivX compression - both of which are flavors of MPEG-4 ASP.

There's nothing wrong with MPEG-4 ASP, but it's definitely not the "latest and the greatest", so to speak. Depending on how much you want to compress your sources, H.264 may give you higher quality. In fact, it will probably be "better" in all cases :devil:

I'd suggest looking at x264, which is an awesomely awesome free, open-source H.264 encoder. Lots of people on doom9 are big fans, myself included! (see my sig? ;))

There are several simple GUIs designed exactly for this task (DVD to H.264 via x264). I'd suggest you take a look at Handbrake. It's a very popular, and easy to use GUI.

Derek

[Usedocne]

I'd second what Blue_MiSfit said about x264. Plus maybe encode your audio to AAC then mux to MP4 (for Xbox 360 compatability).

[mike20021969]

H.264 may give you higher quality....I'd suggest you take a look at Handbrake.
I use Handbrake often. Could I ask this - is there a guideline as to what bit rate you should compress to?
Would you halve, third or quarter whatever the original is? I normally set it to 1500kbps for video/160kbps aac audio, but am never sure if 1500 for the video is right or not.

I have a tons of MPEG2 files from my Canon camcorder recorded @ 6000kbps. I want to maintain the quality, but need to free up HDD space at the same time.

[Blue_MiSfit]

It all depends on how complex the source is. One movie might look like crap at 1500kbps, whereas another might need only 700kbps to look really good.

Instead of worrying about a bitrate, x264 has the option of using "CRF" (Constant Rate Factor) rate control. This means you pick a number from 0 to 51, with typical values being between 18 and 26 - lower numbers representing higher quality. In CRF mode, the encoder always varies the QPs (and thus the bitrate), seeking to achieve a constant quality. It's very, very good! :) It also only requires one encoding pass - a second pass gets you basically no benefit.

The only downside to CRF is that there is basically no predictability as to how much bitrate x264 will use at a given CRF. That being said, if you're storing things on hard drive (and you should be), it's not the end of the world if one movie uses 4mbps, and another uses 1mbps - as long as they both look great... right? :)

Play with it a bit, maybe use a short test clip from a movie/scene you know particularly well. Start with CRF20, and work up or down depending on how it turns out. You'll be quite happy with the results, I assure you!

Keep in mind, I am over simplifying things a tad bit. CRF does not really equal constant quality - that is to say I can't honestly say that if one movie looks perfect with CRF22, all of them will (to my eyes at least).

Regardless, it's a much better way to go about things than shooting in the dark with bitrates though!!!

AAC is a great choice, if you're looking to reduce audio bitrates. I usually don't bother, since AC3 can bitstream as-is over S/PDIF. BluRay audio sources are obscene though (lossless, or LPCM), so I always transcode these to AAC.

I personally like Nero's AAC encoder (free to download). It's used by eac3to and several other tools. I think Handbrake uses FAAC, which is decent, but not quite up to par IMO.

Derek

[yetanotherid]

I use Handbrake often. Could I ask this - is there a guideline as to what bit rate you should compress to?
Would you halve, third or quarter whatever the original is? I normally set it to 1500kbps for video/160kbps aac audio, but am never sure if 1500 for the video is right or not.

I have a tons of MPEG2 files from my Canon camcorder recorded @ 6000kbps. I want to maintain the quality, but need to free up HDD space at the same time.

Why would you set the bitrate? I don't use handbrake but I know it has a constant quality setting like every other GUI. I think it has a slider which changes the quality setting, or constant rate factor. Usual values are between about 18 and 22 (lower = better quality). 18 is supposed to give a virtually transparent encode, but you could probably go down to 16 if you don't mind huge files.... which is what you're trying to rectify by encoding.

The CRF setting will encode to the quality you set and the file size will be whatever it needs to be. It really depends on the video you're encoding and how easy it is to compress. If you're aiming for a particular size then you're probably better off using the target size setting and doing a 2 pass encode, as the way I understand it that'll at least distribute the bits to keep the whole video at the same quality level.... less where they're not needed and more where they are.

I'm not sure how the bits are distributed using the average bit rate setting but I'd assume you use it to aim for a specific file size with a single pass encode, however I'd also assume it's not going to give you a constant quality throughout the entire video.

I'd be using the constant quality setting and maybe running a few test encodes to see what file sizes you end up with, then reducing the quality setting if they're too big. Or maybe consider reducing the resolution a little instead, if applicable. Once you get a CRF and resolution which gives you an average file size you're happy with, then encode the whole lot using that setting.

For DVDs I tend to use a CRF of 18, for HD stuff I tend to drop the CRF to 19 or 20 as using a better quality source the difference isn't very noticeable.... if at all.... and it keeps the file size down.

[yetanotherid]

Beaten to the post by Blue_MiSfit!! :-)

[mike20021969]

@Blue_MiSfit
Thanks for that :)
Why would you set the bitrate?In the past I used DivX converter and the default setting I used was 1300kbps. I heard x264 was better and found Handbrake used it, so thought I'd give it a bit 'extra' in the kbps department - not knowing much about whether I should or not.

[yetanotherid]

In the past I used DivX converter and the default setting I used was 1300kbps. I heard x264 was better and found Handbrake used it, so thought I'd give it a bit 'extra' in the kbps department - not knowing much about whether I should or not.

Even when converting to DivX or XviD you probably would have been better off going for a quality setting rather than a bitrate.
For XviD the quality/file size ratio is supposed to be optimum at a quality setting of around 70 to 75%. I used to use AutoGK for XviD conversion..... I'd just set it to 75% and let the bitrate and file size be whatever they'd be.

[mike20021969]

Even when converting to DivX...you probably would have been better off going for a quality setting rather than a bitrate.
In DivX converter, there wasn't a video quality setting. The chosen profile had a default kbps setting - this could be set to a new kbps value (audio kbps could be set aswell).

[yetanotherid]

In DivX converter, there wasn't a video quality setting. The chosen profile had a default kbps setting - this could be set to a new kbps value (audio kbps could be set aswell).

I guess you've been using the wrong program then ;)