192kbs to 320?

[cryotek]

Dear people,

I have a dvd video that I need to encode. the proces is making a mkv then demuxing it and then importing it into premiere. The export from premiere is:
Video - mp4
Compressor - H264
Data rate - max 20Mbps
Resolution - 1080p or native
Aspect ratio - 16/9
Color space - RGB
Audio: AAC @ 44KHz

My queries are whether to change the bitrate to 320kbps or leave it to its original 192kpbs.

Thank you in advance

[Cornucopia]

Without more info and a reason WHY you would need to do this, my 1st guess suggestion would be to leave it alone.

Media compression rule #7: Raising bitrate on an already compressed stream WILL NOT EVER improve the quality, but, like any re-compression, will somewhat lower quality.
How much depends on many factors.

Scott

[cryotek]

Thanks for the fast reply,

Well, I need this for a short film festival projection. It's an animation with these specs:

video

codec: MPEG -1/2
resolutin: 720x480
frame rate: 29.97
decoded format: planar 4:2:0 YUV

audio

codec AC3
channels stereo
sample rate 48000
bitrate 192 kb/s

Laur

[Cornucopia]

You have to reconvert anyway because your source samplerate doesn't match the target, nor does the codec.

If the venue SPECIFIES 192, give them 192, regardless.

Scott

[cryotek]

The thing is that those specs are from the original dvd. I need to convert the dvd for the projection. And they want this:

Video - MP4
Compressor - H264
Data rate - max 20Mbps
Resolution - 1080p or native
Aspect ratio - 16/9
Color space - RGB
Audio: uncompressed PCM or Mpeg4 AAC @ 44KHz

Anyway, I understand that I should keep the bitrate to match the original.

And thanks!!!

[Cornucopia]

No, you should match the bitrate with what is expected. As should all other parameters: match what they ask for.

You really need to stop giving piecemeal information!

First, I think you are doing a disservice to the quality by converting, muxing, importing, lossy re-encoding and then lossy re-encoding again (by the sound of it).

The most straightforward way is the best. Do only 1 lossy convert: the last one. All the rest should be ~lossless.

So, what I would do would be:
1. Rip DVD->MPG
2. Upsize & Upconvert to Lagarith/HuffYUV/UTvideo-type .AVI HD files (whatever works in your editor).
3. Edit in your editor and save the edit master as the same type .AVI HD file.
4. Encode with MeGUI using x.264 codec and either do a couple of CRF/Quality-based encodes to find your 20Mbps limit, or do a 2passVBR bitrate-based encode, specifying your 20Mbps.

As far as the audio goes, my STRONG recommendation is to:
1. Decode the AC3 to 48kHz LPCM stereo wav. That works out to 1500kbps.
2. In the editor or separately (depending on how good it is), do a sample rate conversion to 44.1kHz LPCM stereo wav. This now becomes 1378.125kbps
3. If you can get ffmpeg, etc. to mux in LPCM to wav, give that a try. That will give you the BEST quality possible (nearly equal to the original AC3).
4. If not, and maybe even in addition, encode the LPCM to AAC (I like the LameXP interface) to your highest allowable bitrate (you don't mention those bitrate specs). 320 might be ok there. You could also use VBR if you desired and they were ok with it.
5. Mux that into your MP4 (Yamb, ffmpeg, etc).
6. You could also skip the LPCM-in-MP4 bit and the external-AAC-in-MP4 bit and just encode AAC into the MP4 while in MeGUI for the video. There's a very good likelihood that the venue wouldn't really know how to handle LPCM in an MP4 anyway. Kills 2 birds with one stone.

Sounds like the venue doesn't really know much about compression: "RGB colorspace" is impossible in any existing H264 profile. Then there's the LPCM business, and 20Mbps is low for a final HD projection master that is intended for pro/semi-pro viewing. Plus, 44.1kHz is non-standard for digital audio that accompanies video (~90% of pro/semi-pro cams shoot at 48kHz). Oh, well...you've got to play the game by their rules, even if they're ill-conceived rules.

Your H264 encode will likely be MP@L4.0 (fits the suggested spec), which is YUV 4:2:0, just like your source. So at least you won't have to do a colorspace conversion. If they complain, point them in my direction!

You never said whether or not your source was 16:9, so that's another can of worms...

Now, what about interlace?...

Scott

[cryotek]

All the movies are animations.

The video source is 4:3 but I also have other dvd's wich are 16:9.

I don't need to do any modification in terms of lengh or add titles. I just need to encode from dvd to h264 for screening.

Also the tool used for screening is a Popcorn C-200. About that, the venue said that last year there were problems with files >20Mbps.

So I have tried to upsize & upconvert to a UTvideo. AVI HD file from an mpeg. I am using Video Enhancer 1.9. This software has an option called Super Resolution that lets me...resize the video. So should I resize the video to 1080 and then go directly with it in Megui or should I resize it to what they suggest (1440x960) and then import it in Premiere, make a 1080p sequence and save the edit master as the same type .AVI HD file?

Also, when I choose the UTvideo codec there are a few things that I don't know like what BT to use? Also I have other options like VCM or DMO and some configure button.

Thanks again.

[Cornucopia]

Those guys are screwy! Or they're doing something very wrong (maybe they're using a very slow external drive?)...

PopcornHour C200 supports AVC+AAC in MP4 at Level 4.1. That means it should be fine up to 1080p30 or 720p60 at up to 50Mbps in Main Profile & 62Mbps in High Profile (whichever one PH supports). BTW, those profiles are both YUV 4:2:0, NOT RGB.

Also, what they didn't tell you is that PH also supports standard MPEG2+AC3 in Mpeg2-PS, aka a straight rip from your DVD, without needing to reconvert anything (just a decrypt+optional Vob2Mpg). See manual pages 116-119.

...There you go again with the piecemeal info! Nowhere earlier did you mention anything about 1440x960. Who suggested this? What ELSE did they suggest?

If you are going to be using Premiere to edit with, you could also use it to resize, unless you prefer VE. BTW, VE costs something. Using resize algorithms in ffmpeg/Virtualdub/AVISynth cost nothing and can probably get you 90% of what VE can get you (maybe more than 100% depending upon the material). Choose VE only if you are already assured of its other benefits.

Again, do 1 lossy conversion (hopefully AT THE END). That loss includes AVC/h.264 compression, but it could also include the blurring accompanying interpolation due to upsizing. So that too should ONLY be done once (if at all - you could leave things alone and let the player/projector/display do the upsizing).
I stand by what I said earlier (WRT upsizing) - 720x480 -> 1920x1080, that's it.

RE: which UTvideo option - use YUV420. Use BT.601 if still in SD(DVD) resolutions. Use BT.709 if in HD resolutions. VCM vs. DMO refers to Windows' media architecture APIs: VCM = Video Compression Manager, a part of VfW or VideoforWindows (older), DMO = Directshow Media Object/Operator, a part of Directshow (newer). Use whatever works with the remainder of your system (e.g. if I were using this in Virtualdub, only the VfW aka VCM options would be available, same with Premiere)...

Scott

...OK, new question: why do your DVDs have 720x480 (aka NTSC) when you are in Romania (aka PAL land)? That's another complicating factor...

[cryotek]

But the POPCORN C200 doesn't upscale. Al least I didn't find in the manual/ So if I play a Mpeg2-PS will this look terrible on the big screen?

RE:"...There you go again with the piecemeal info! Nowhere earlier did you mention anything about 1440x960. Who suggested this? What ELSE did they suggest?"

my mistake, nevermind.

RE: why do your DVDs have 720x480 (aka NTSC) when you are in Romania (aka PAL land)?


The DVD's are sent from the U.S.A.

Q: What does WRT stands from?

Also, I noticed that a lot of movies have diferent audio levels. Some have -9 db, some 0 db. Should I dare raise or lower the art?

[El Heggunte]

Q: What does WRT stand for?

« With Regard To / With Respect To »

[Cornucopia]

Yes, the PH does upscale:

Manual pages 69,70 show TV mode can be changed (Auto vs. 480/576 vs. 720 vs. 1080) as well as the Zoom mode (Actual size vs. Fit-to-screen, etc).

And if you use HDMI, even if the player didn't upscale, the display (projector/TV) would likely do it for you.

Scott

[cryotek]

Thank you Scott. Really nice forums you have here.

[cryotek]

I'm back. I'm encoding some blurays with RipBot and it seems that the it has onlya a AAC 128kbps stereo audio option. Is it good for big film projection?

[Cornucopia]

Some might find that acceptable. Seems a little low to me (for "projection"). Why RipBot?

Scott

[cryotek]

What else is there besides ripbot? and free. I'm doing h264 compression.

I dont know whether to do or not an upscale to some videos in Premiere. I know it does some kind of blur over the video if it's not x2. What do you suggest?