[PROBLEM] USB 2.0 DVDRW can't read DVD

[mk01]

(31st Jul, 2013 10:45 PM)f1vefour Wrote:  I wonder if it wouldn't be possible to encode a dvdiso on-the-fly and play this.

definitely yes! with 16RPIs in cloud.

what is basic data rate of dvd speed 1x with mpeg2? 10mbit/s?

ok, that's 1.2MB/s, writing. but you need read as well. so your RPi will barely read encrypted data, maybe with the same speed write them to output.

and we missed decoding. and we of course want the audio as well. but we spent all the cpu cycles on reading the drive

[f1vefour]

(31st Jul, 2013 11:18 PM)mk01 Wrote:  

(31st Jul, 2013 10:45 PM)f1vefour Wrote:  I wonder if it wouldn't be possible to encode a dvdiso on-the-fly and play this.

definitely yes! with 16RPIs in cloud.

what is basic data rate of dvd speed 1x with mpeg2? 10mbit/s?

ok, that's 1.2MB/s, writing. but you need read as well. so your RPi will barely read encrypted data, maybe with the same speed write them to output.

and we missed decoding. and we of course want the audio as well. but we spent all the cpu cycles on reading the drive

Hahaha

Write the ISO at 1x and it will of course be read a 1x (realtime) giving us just 2.4MB/s of io.

Decryption at this slow speed shouldn't be too heavy on the CPU but this is speculation as I don't have the hardware to try it, the GPU will be playing the ISO. Seems theoretically possible and in the end you would have an unencrypted ISO of the DVD.

I'm sure no Xbian developer is going to take this on, just throwing ideas out there for someone who might want to give it a go.

[mk01]

(31st Jul, 2013 11:28 PM)f1vefour Wrote:  Write the ISO at 1x and it will of course be read a 1x (realtime) giving us just 2.4MB/s of io.

I'm sure no Xbian developer is going to take this on, just throwing ideas out there for someone who might want to give it a go.

I'm afraid those 2.4MB/s is sustained peak of io what RPI can deliver at max.

There is similar discussion going on in the background, which I'm quite interested in - AAC -> AC3 online recoding. As there is no passthrough for AAC available, all "certified" mp4 (H264 video + 2ch AAC + 5.1ch AAC) are playing stereo only (even on AC3/DTS/LPCM hw capable AVR decoder). The official statement is "no free cpu cycles to transcode the 6 channels", but I remember same discussion three years ago with ATV2.

Now, the AAC->AC3 is native to ATV2 version of xbmc, but forcing me to preprocess such video files and add additional audio of AC3. doesn't take more than 3-5 minutes, but still it's not the stupid-proof setup as ATV2 was.

So you never know - it will come the day.

[f1vefour]

XBMC is generally running at %50 CPU usage during playback, I would think recoding AAC -> AC3 would be plausible but wouldn't you have to remux also?

[rikardo1979]

i dont want be so pessimistic but I dont see the way with the RPi CPU and amount of RAM.
The thing that RPi is capable to play Full HD is that all is go through GPU whis is fully used by omxplayer.
Also thats the way why none of the external players would work as there would not be HW acceleration.
So to me this is a dead end an I would just recommend rip all your dvd or iso to something like avi or mkv

[mk01]

(31st Jul, 2013 11:49 PM)f1vefour Wrote:  XBMC is generally running at %50 CPU usage during playback, I would think recoding AAC -> AC3 would be plausible but wouldn't you have to remux also?

Exactly this is what I think as well. I was never looking more into this topic, but I suppose we have just to demux the signal, with passthrough it goes away separately.

And the demux is actually taking place anyhow as the RPI is already mixing down the channels from 5.1 to 2 (but if I remember right, part of this is going through the GPU<>HDMI part already). There are even going rumors around, that the GPU is able to hw decode DTS-HD and license agreement with license holders should be possible, but...

I somehow skipped the DVD ages, iTunes licensing allowed me to transfer all my CD into electronic versions via iTunes Match and the few DVDs I had I simply recoded to iso files, which XBMC plays nicely, even with chapters, menu entries etc. And currently everything is coming as data streams / files for movies as well from iTunes for few bucks. But purely AAC . So i'm still keeping my ATV2s nearby.

But being too much off topic, what we want to try? Accessing cd/dvd reader from within XBMC on RPI?

[f1vefour]

(1st Aug, 2013 12:06 AM)rikardo1979 Wrote:  i dont want be so pessimistic but I dont see the way with the RPi CPU and amount of RAM.
The thing that RPi is capable to play Full HD is that all is go through GPU whis is fully used by omxplayer.
Also thats the way why none of the external players would work as there would not be HW acceleration.
So to me this is a dead end an I would just recommend rip all your dvd or iso to something like avi or mkv

omxplayer can play unencrypted DVD ISO's

XBMC handles the menus and such, omxplayer handles the mpeg2 vob streams. I have a few ISO files and Xbian XBMC can play them.

[rikardo1979]

yes thats the thing as more if not all DVD's use encryption

[f1vefour]

@mk01

Do you currently compile XBMC with the --disable-optical-drive?

You could do a test build with --enable-dvdcss then try to play a DVD and see what happens.

[rikardo1979]

(1st Aug, 2013 12:22 AM)f1vefour Wrote:  @mk01

Do you currently compile XBMC with the --disable-optical-drive?

You could do a test build with --enable-dvdcss then try to play a DVD and see what happens.

I'm pretty sure we or some one somewhere tried this and it wasnt good .

[f1vefour]

It probably won't function Richard, wouldn't hurt to do a local build and try it though. Perhaps Xbian could be the first RPi distribution to support DVD playback some day.

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(1st Aug, 2013 12:18 AM)rikardo1979 Wrote:  yes thats the thing as more if not all DVD's use encryption

They mostly do, that's what dvdcss is for in XBMC.

[mk01]

(1st Aug, 2013 12:53 AM)f1vefour Wrote:  It probably won't function Richard, wouldn't hurt to do a local build and try it though. Perhaps Xbian could be the first RPi distribution to support DVD playback some day.

feel free to approach Koenn and ask him to recompile with those two options.

he is auto-compiling daily... it's worth try, it's for free

[f1vefour]

(1st Aug, 2013 01:00 AM)mk01 Wrote:  

(1st Aug, 2013 12:53 AM)f1vefour Wrote:  It probably won't function Richard, wouldn't hurt to do a local build and try it though. Perhaps Xbian could be the first RPi distribution to support DVD playback some day.

feel free to approach Koenn and ask him to recompile with those two options.

he is auto-compiling daily... it's worth try, it's for free

I will leave it up to the user looking for DVD playback, it is an unimportant feature for my personal use as I don't have a USB DVD drive.

Thanks for the information though.

[mk01]

ok, haven't checked the author of the topic.

[rubin110]

Wow lots of discussion.

So to clarify, with Xbian latest beta I was able to get a Region 1 DVD movie to start up, play the video intro to whatever the movie house made Seven, then get into the DVD menu. I was able to interact with the menu, but was unable to start up the actual movie.

It's been a long while since I've looked into how DVD movies are built. This encryption you all speak of, is it the whole disc or just particular VOB files on the disc? Would that be specifically why when I try to play the video it barfs?

Starting to feel like an easier solution is to just plug the DVD drive to my server and ask my housemates who insist on wanting to watch DVD movies to simply pop the disc into that drive and have a series of scripts deal with ripping, transcoding, and dumping it somewhere on the network for Xbian to play.

I hate optical media.