View Full Version : Extract a single chapter

22nd August 2008, 10:51
My question is hopefully very simple. How can I extract a single chapter of video/audio/subtitle from HD-DVD (or BluRay for that matter)

I'm working to convert my HD-DVDs into x264/mkv, which is all fine and I'm happy with the process. What I'm try to do at present is work through the best optimised settings to get the best quality. I'm checking into differences I can achieve around deblocking with 1:-1:-1 compared to 1:0:0 and also using subme of 7 as well as some other small tweaks (e.g. refs, and also me-prepass)

Now I don't want to do an entire film each time, as that takes a few hours ;)

I have the bitrate I want to work with (based on a full encode of the film with fixed sized to 8150). So I want to just work on a single chapter for me to do quicker encoded and comparisons to get my preferred settings etc.

I've looked at eac3to and evodemux (and tsremux/tsmuxer for BluRay) but I can't see a way to achieve what I'm after with the options they have. I want to be able to do this for both HD-DVDs and BluRay, although its very likely once I settle on settings that are generic for quality, I doubt I'll look to do things differently until get around to looking at any anime.

Any ideas anyone ?

22nd August 2008, 12:48
When i was testing and learning i used eac3to to get the trailer off disc 2 of my Transformers HDDVD and worked on that, it was 500mb and only a few minutes, and resonably quick to encode, well as fast as my poor e6300 would go... thank god it's gone!

Or you could use mencoder with the -ss and -endpos options....

On another note try reencoding with crf rather than a fixed bitrate, or atleast do 2 pass encoding......

23rd August 2008, 13:27
Thanks for the pointers. I am going to try mencoder as I'm specifically trying to "fix" scene fades in some of HD-DVDs. To give an example, the following scene @ 01:56:05 to 07 tends to have poor detail on the right of the image with the building, which at the next I/P-frame is "refreshed" to a clean image.

The frame image (see attachment) was taken from an encode using the following paramters in x264
cabac=1 / ref=4 / deblock=1:-1:-1 / analyse=0x3:0x133 / me=esa / subme=7 / psy_rd=1.000000 / brdo=1 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=0 / 8x8dct=1 / cqm=0 / deadzone=21,11 / chroma_qp_offset=0 / threads=6 / nr=0 / decimate=1 / mbaff=0 / bframes=3 / b_pyramid=1 / b_adapt=1 / b_bias=0 / direct=3 / wpredb=1 / bime=1 / keyint=250 / keyint_min=25 / scenecut=40(pre) / rc=2pass / bitrate=6424 / ratetol=1.0 / rceq='blurCplx^(1-qComp)' / qcomp=1.00 / qpmin=10 / qpmax=51 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / vbv_maxrate=30000 / vbv_bufsize=30000 / ip_ratio=1.40 / pb_ratio=1.30 / aq=2:1.00
Note that the impact/benefit of me=esa over me=umh is nil to the human eye (well my eyes anyway) for this issue, yet adds almost twice the encoding time with subme=7 set as well.

I'm intending to look at encoding that chapter with adjustments in :-

me_range - try going from 16 (default) to 24
deadzone - try going from 21,11 (default) to 10,6 or perhaps 6,4
deblock - try with -2 and -3 in both alpha:beta to sharpen image

So if I can get just that chapter, it will mean I can play around with settings in x264 to my hearts content without encoding for 10 hours for the complete movie !

23rd August 2008, 14:40
Instead of faffing around, I'm just going to use the trim parameter in the avs to encode just what I'm after. e.g. trim(159712,165897)