Lowering bitrate FAST (DVD Backuping large titles)

[Wizeman]

Maybe everyone in the world already but it was bit of a revelation to me.

QuickTime 6 can export to MPEG-2 at a user-selectable bitrate. Great news, I thought to myself, and promptly tried to rip a large DVD, lower the bitrate and put it on a DVD-r. Then I noticed that the guys over at Apple weren't to pleased about that idea, so they fixed it so the option to export to MPEG-2 disappears if the file you want to export already *is* a MPEG-2/.m2v. <sigh> Pity, since the Apple MPEG-2 encoder is surprisingly good - not to mention VERY fast.

*BUT*

Example (Widescreen film)
1) Create a black 720x404 square in Graphic Converter. Save it as a PICT file.
2) Open the PICT file in QT 6.
3) Drag the .m2v file into the black square. (You get this file by, for example, ripping a DVD w OSex and choosing Elementary streams rather than Program streams.)
4) Voila. As far as QuickTime is concerned, this file is *still* a PICT. Which means you can export as (drumroll here) MPEG-2.

On my iMac G4/800, it takes about twice the movie length to re-encode. Then you simply import the .m2v and the .ac3 into DVDSP (no need to do anything at all to the audio, since we're making a DVD here) and burn. Or mux it w your muxer of choice, and burn.

/Wizeman

P.S.
"Wait, can't I make an SVCD like this!?" I hear you cry. Well, yes and no. I haven't found a way of getting around QuickTime 6 MPEG-2 settings, which mean that all the video streams you export will be 720x576 rather than the usual SVCD 480x576(PAL) or 480x480(NTSC). Some players will still play this as XSVCD though, and since it is the bitrate that determines the actual file size (and not the aspect ratio...) this might work. Not too wild about the idea myself though, I'd rather use ffmpegx that takes about twice as long but still rocks pretty hard.

[Macnewbie]

Yep. This was discovered about a month ago. There have been some threads on it here and at the RipDifferent forums.

[AntnyMD]

The downside to using the MPEG-2 export in Quicktime 6 Pro (w/DVDSP) is that it makes only constant bitrate encodes, and forces the 720x480/576 resolution, whereas in mpeg2enc (as used in ffmpegX), you can make half D1 encodes, or 352x480/576 which reveals slightly higher quality encodes at SVCD bitrates.

[erzimeriah]

Actually you can lower the bitrate of an mpeg using quictime, you just have to trick quicktime into thinking it is something other than an mpeg2. The mpeg2 has to be under 2 GB for quicktime to do anything with it. I have had success reencoding by using Mpeg info to find out the size of the video, then I make a photoshop file that is the same size. I then import that into quictime pro, after that I drag and drop my mpeg into quictime. Then you can export the mpeg2 as an mpeg2 and lower the bitrate.

The only downside I've run into is not being able to join the mpeg2's together after reencoding them. I'm working on it though.

[Macnewbie]

Actually you can lower the bitrate of an mpeg using quictime, you just have to trick quicktime into thinking it is something other than an mpeg2. The mpeg2 has to be under 2 GB for quicktime to do anything with it. I have had success reencoding by using Mpeg info to find out the size of the video, then I make a photoshop file that is the same size. I then import that into quictime pro, after that I drag and drop my mpeg into quictime. Then you can export the mpeg2 as an mpeg2 and lower the bitrate.

Uhh, isn't that what the original post said?

[erzimeriah]

**** you

[erzimeriah]

yeah i guess it was. no need to be an ******* though.

[Monkichi57]

What i tried and worked is that you drop each m2v one by one into the pict file in QT, then export it with a lower bitrate. Mine worked fine after.
:P

[Tolly]

hey erzimeriah:

try what Monkichi57 said and drop them in one by one, or check out mpgtx if u havent already, its supposed to have a good join feature that has been sucessful for me so far. u can get it here:
http://www.biermann.org/philipp/mpegcut/

hope to help, if u havent tried these already. good luck!