Tag Archives: Technology

Google Reader ; giving it a 2nd try and impressed

RSS (Really Simple Syndication) allows a web site to provide a newsfeed (headlines, summaries) of their stories. This can range from an international newspaper to my humble blog, whereupon your eyes are now feasting.

Users can then subscribe to that newsfeed and hence quickly find out when new articles are added to the original site…without having to go to that site as such. An RSS reader is used to not only handle the subscriptions, but also regularly fetch and show the headlines/summaries. From there you can click on a link to read the main body of the story, if it interests you.

A benefit of such readers is that in one place you can see multiple subscriptions. So my reader allows me to quickly see the headlines and summaries from about 10 web sites; Australian IT News, two astronomy information sites, two on Australian TV news and ratings…and even one on Beatles music and news (!).

It effectively gives you the ability to create your own newspaper, albeit using other peoples articles. But it’s your paper, with topics that interest you.

In the olden days (2006, ha ha) RSS readers were separate programs you installed on your PC or Mac etc. Today Google provides one that runs within your browser and hence you can access it from anywhere. It’s called, somewhat surprisingly, Google Reader

Initially I couldn’t see much benefit for me, but gave it a second chance last week. And I have to say it’s working for me. Having the key info from many web sites in the one place is excellent. You can group similar feeds into your own ‘folders’ for ease of navigation. I’ve got Technology, Science and Music so far. It’s even made it to my Firefox Bookmarks toolbar, right there next to Digg and The Age newspaper. Both of whom, of course, provide multiple RSS feeds.

PVRs : Chapter 1

Personal Video Recorders (PVR) are all the go. They let you record digital TV, usually to a hard drive.  I myself prefer hard drives over the ‘record to DVD’ models; extra capacity and – if you choose correctly – you can always burn a DVD copy of the show from hard drive anyway.

At their simplest a PVR can replace your current VHS video recorder, but with extra functions, such as the ability to watch and record at the same time. Even these models can support the use of an Electronic Program Guide, so you can record West Wing simply by selecting it’s name from a menu (rather than manually: Channel Blah at Blah O’clock on a Saturday for 90 minutes)

Beyond that it’s onward and upward. Dual tuners. High Definition. The ability to copy recordings off to your PC (so you can save them and/or free up space on the PVR’s hard drive).

Anyway the local PVR market seems to be in 3 categories:

  1. Entry Level  (single or dual tuner, can’t copy recordings off to a PC)
  2. Basic (same as Entry Level, but can copy off recordings)
  3. Premium (same as Basic, but functionality can be extended via user-provided plug-ins . Also regarded as having ‘better’ build quality and/or support)

As a good guideline the price increases as you move from 1 to 2 to 3.  Also there are Standard Definition (SD) and High Definition (HD) offerings in all categories.

In addition I’d be looking for the ability to upgrade the PVR’s firmware. Preferably via an ‘official’ Internet source, particularly if you – the user – aren’t confident in these things.

Entry Level:  I’ve seen dual-SD-tuner Digicrystal boxes for $260 at Strathfield, which is a quite cheap price. The firmware can be upgraded, which is just as well as early users reported some bad problems with the remote control.

Basic: Dick Smith have a dual SD-tuner PVR for about $400, dual HD-tuner one’s about $800.

Premium: Topfield reigns here. About $700 for dual SD and $1200 for dual HD.

The Dick Smith store I went to had terrible support, the guy obviously had no idea about these things…and I wasn’t bombarding him with questions, just asking him if they had any. He wasn’t sure (!). I have read that you get better service (and prices) via going to their PowerHouse super stores, so maybe on the weekend

The local Digital TV forum has some excellent discussion on this topic.

Powered by ScribeFire.

Lotsa backup CDs to a few DVDs to one Blu-Ray

It just seemed like yesterday when I’d back up my data to 1 CD (that is about 0.7 GB). Yes, this was before I got my first digital camera and my TV card, so I didn’t have that much data.

Now I used DVDs. Specifically single-layer, single sided. They hold about 4.7 GB.

I must admit to wondering (okay, worrying) about the durability of those old CD back ups. What if the media fails? So recently I’ve started consolidating the old CD backups onto DVDs.

It’s about 6:1, I can squash 6 CDs onto 1 DVD.

And so to Blu-Ray. The smallest capacity (single sided, single layer) Blu-Ray disk is 25 GB. So I can further consolidate; copy my DVD back ups onto Blu-Ray. Once I get a burner :-)

The ratio is a pleasant 5:1. So, 5 DVDs onto 1 Blu-Ray disk. Or, if you do the maths, 30 CDs.

So, all of my old data backup CDs can easily fit on the smallest Blu-Ray.

My Kit – Part 3 : The Video and Audio stuff

And now to the heart of the matter :-)

Organising, Viewing and Playing Back

For pictures I keep things organised with Picasa2. For quick viewing of single shots (and some basic editing) it’s IrfanView

For audio I organise, bulk listen, grab podcasts etc with iTunes. For individual files it’s Winamp.

For video I mainly use VLC, but sometimes will fall back to the old favourite Media Player Classic, which uses the cool ffdshow to do some extra smart work.

For recording

To do audio recordings I use Audacity. It can also do sound processing and convert to MP3 etc.

As for digital TV recordings, I have a Nebula Electronics DigiTV box. This high defintion USB-based system is very reliable and gives excellent results.

For video conversion

I use the wonderful MeGUI to convert my videos. Bit of a learning curve, but well worth it. Great stuff, developed and supported by a smart bunch. I convert to X.264 (an open version of H.264; the leading-edge video conversion scheme )

If it’s a TV recording – from the Nebula box – I will first pass it through VideoReDo Plus. This frame-accurate MPEG editor let’s me remove the ‘junk’ before and after the main show as well as get rid of the ads. I don’t record (keep) that many commercial TV shows, so don’t use the ad-removal that much.

High Definition AVI sample

I’ve seen a sample of a high defintion (720 lines, progressive) AVI with AC3 (Dolby Digital  5.1 surround sound). The quality of the picture and sound was stunning.

Some rough comparisons for how big a 38 minute recoding is, for different quality and type. This is for the lot, sound and video:

  • Standard defintion TV recording (MPEG2):  1.5 GB
  • Compressed to ok quality MPEG4 (XviD or AVC):   230 MB  or 0.22 GB
  • The above Hi Def AVI -  MPEG4 (DivX) : 1 GB

My Kit – Part 1 : The TV room

I use an old PC plugged into the new LCD TV and the amp (receiver)

The LCD TV has a fair few inputs, one of which is a standard PC socket. I had planned to just test this out before moving to the ‘real’ one; the pure digitial HDMI. However the picture quality was excellent so the digital socket is free for a BluRay player one day. The rest of the kit is:

  • I am licensed for Windows XP so left that on the PC.
  • The free and open source (foss) Media Portal is my media centre software. Besides being an excellent librarian for my video files, it keeps track of where I’m up to in each.  Saves a lot of remembering or writing down that I was 28 mins and 15 seconds into file2test.avi. Invaluable. Supports remote shares directly via UNC, so no need to map drives.
  • The excellent, powerful foss ffdshow provides a number of useful codecs plus enables me to then ‘post process’ the video; that is sharpen-up divx, xvid, mkv (x264) files. The compression used in these files usually makes the picture ‘soft’ or a bit blurry. ffdshow is a great way to sharpen the image back up.
  • In fact I use the uber-cool avisynth to help out ffdshow too; another must-have application.
  • Rather than keep getting up to control the Media Portal, I’ve got a dedicated PC-remote for media centers; an iMon Station. Now that works a treat!

Most stuff is shown (streamed) from the PC in the study over wired Ethernet. This PC also has the HD/SD USB2 digitial tv box, so recordings are made on the Study PC and streamed to the 2nd PC in the lounge room. More on the Study PC in another post,

The lounge PC also supports digital sound out, so it can send the Dolby 5.1 or DTS etc signal to the amp for conversion to surround sound. Happy to report it too works.

How much ‘modern’ movie compression can fit on a CD?

If you wanted to compress a movie (say a DVD) down to fit on a CD and use modern compression schemes; yes AVC (via the X264 codec) and AAC for the audio…what sort of length movie could you use and still get good results?

Assume

  • 1 CD is 700 MB
  • The AAC audio is 128 kbps (average bit rate)

Knowing the target file size and movie length, it’s possible to work out the required target bit rate of the video stream to fill the 700 MB CD. Here’s the required bitrate as a function of movie length:

1 hour movie need to set it at  1501 kbps
1.5 hour   957
2 hour   685

The bit rate is a good indicator of quality too. So a 1 hour movie would be great quality, 90 mins very good indeed, but by 2 hours you would probably see some artefacts.

Note: the above calculations do take into account the audio track and the (small) overhead of the mp4 or mkv container.

The above quality is only based on the data rate. Another factor is the trade-off between compression time and quality; they are almost in a linear relationship.  For the 2 hour one you could use one of the ’1 Pass’ profiles and get the movie to fit on the CD and take only about 2.5 hours to do so, but the quality could be a wee bit dodgy. 

You could increase this quality by using one of the ‘slower’ (HQ or CE) encoding profiles as per my other posts. I’d suggest if you left it running over night, you could compress down a 2 hour film at that data rate (685) and get quite good quality. Would be interesting to try.

 

Single pass for quick AVC encoding of TV recordings

One of the benefits of AVC is the ability to adapt the compression to suit the target device or quality. So you can use a very high quality set of settings and take 19 hours to compress a 2 hour movie. By the way even these are not the highest quality (read: slowest) settings.

The good people over at the doom9 forum have already created a number of Profiles which you load into MeGUI and then choose from a drop down list. They range from the above multi-pass through to ” I just need an okay compression” quick single pass.

Even within such single passes they offer at least 3 profiles, balancing speed of encoding against quality:

1P-Maxspeed: Everything disabled for max encoding speed (good for live capturing).
1P-Intermediate: Intermediate settings for average speed and final quality.
1P-Goodquality: Settings for good quality with 1 pass.

(Source: above doom9 forum post)

You can also use these as a basis and create your own profiles too.

I did a quick series of tests on a 2 minute DVD sample (video only) to confirm these three – unchanged from defaults – work as designed :

  • 1P-Maxspeed: About 2 mins
  • 1P-Intermediate: About 5 mins
  • 1P-Goodquality: About 8.5 mins

On balance, I’d be aiming for 1P-Intermediate. If it’s a show that has little or no movement – say, a chat or comedy show – I’d probably copy that profile and drop the data rate to say 700kpbs from the default of 1000.

AVC and AAC compression timings for 1 hour DVD movie (black and white)

Using MeGUI I took just over 1 hour of DVD and compressed it down via the ‘state of the art’ compression schemes:

  • Video AVC (aka H.264 or MPEG4 Part 10) using the CE_Highprofile at 1000 kbps
  • Audio AAC using the FAAC 128 kbps ABR profile

The 1 hour, 5minute movie took over 5 hours to compress on a Pentium 4 3 GHz. This VOB had already been decrypted; so add another 15 mins for that step. Here’s the breakdown of the MeGUI timings:

  • Indexing the VOB to make a D2V file: 2 mins
  • AAC audio: 8 mins
  • AVC pass 1 of 2: 1 hour 10 mins
  • AVC pass 2 of 2: 4 hours 5 mins
  • Muxing of AAC and AVC to final MP4 file: 3 mins

A great thing about MeGUI is that all of the above is done without user interaction; via the One Click Encoding option. Pass 1 reported 23 fps, Pass 2 reported 6.7 fps

Quality looks excellent on final mp4 file. It started at noon and was done just after 5:25 pm.

Size comparison for this 1 hour 5 minute movie:

  • Original decrypted VOB is: 3.92 GB
  • Final mp4 is: 534 MB

But, to be fair, VOB has multiple soundtracks. Also this is an old black and white movie. Will try colour when I have another 5 hours to spare :-)