Blog
Page: 0 ... 5 ... 10 ... 15 ... 20 ... 25 ... 30 ... 35 ... 40 ... 45 ... 50 51 52 53
Mpeg2 Non-Destructive Editing Workflow
Date: 27/1/2006
I am in the process of editing out duplicate scenes in 6+ hours of DVD format MPEG2 files. Joy!

And at the moment the workflow consists of:
  • Load file in to Media Player Classic and write down rough start/end points of each duplicate scene.
  • Load PVAStrumento to demux the MPEG2 stream into separate video and audio.
  • Load these files into Cuttermaran and mark all the in/out points in the file. Generally the "in" point marks the beginning of a part you want to keep and the "out" point marks the end. You should not make the out point the first I frame of the next scene but rather the last B or P frame of the previous scene, otherwise you get a 1 frame flicker of that scene at the out point.
  • Then as I'm saving the edited video in Cuttermaran I ask it to remux the streams together.


This seams to provide excellent results but it is somewhat time consuming. Is there a better way to delete scenes in MPEG2 without re-encoding any video? (No shareware or warez please)
(5) Comments | Add Comment

Mac Port
Date: 21/1/2006
Let it be known henceforth that the memory bitmap code in Lgi doth draw upon thine Quartz 2d contexts in wonderous colour.

And late on the Saturday evening, fret saw it was good and went henceforth unto his rest.

Selah ;)
(4) Comments | Add Comment

DirectShow Filter Graphs
Date: 12/1/2006
I'm trying to write a directshow filter graph that will convert a dvd-ms file into a normal AVI with standard compression filters (like XviD and Mp3).





I seems to get all the filters hooked up right but then when I "Run" the graph nothing happens... it just sits there in the running state not doing anything. The CPU is idle and the output file is either 0kb or a few hundred K. Same thing happens in the DX8.1 graphedit application.

As a side issue I can't figure out how to bring up the codec filter's settings dialog.

Ideas?
(2) Comments | Add Comment

Review: XpertVision nVidia 6200 256mb AGP
Date: 8/1/2006
Product: ExpertVision nVidia 6200 256mb AGP

Score: 3/5


Pros:
  • Price (cheap)
  • No fan (quiet)
  • Great video out options
Cons:
  • Output corruption
  • Flakey TV breakout connector
  • Average 3d performance
I needed a better 3d card to work on some software I was developing so I ditched my aging (but still good) Matrox G400 and went shopping for a new video card. My primary concern was low cost, but low noise was a close second. So after a bit of poking around on the internet the ExpertVision 6200 seemed like it fit the bill, cheap, no fan and some decent 3d support, as well as TV out. So I picked one up for the low margin retails around here and plonked it into my box (Athlon 1.4ghz, 512mb). It installed fairly easily and I was up and running in 2d in no time. All the PCI slots are full on my motherboard and yet the heat sink fitted anyway, however it was a bit snug.

The first area I tried was the 3d performance so I downloaded some current game demos and fired them up. 3d performance was reasonable, but I'm not going to benchmark anything, as I don't have an array of cards to test against. And thats not the point of this review. However I did find that some games, notably Doom 3 had lots of texture corruption and shearing issues. Which I found annoying. Less demanding games seemed to run fine, e.g. Counter Strike has no issues. I don't however do a lot of gaming so it doesn't really worry me.

2D performance is fine, I get a sharp picture with both the analogue and digital outputs. For everyday browsing and so on it's as good as more expensive cards. However for the first few months I had the card it would occasionally cease functioning by turning the screen blank, well almost blank... if you turn the monitor bightness all the way up you can faintly see a distorted view of the desktop. I made a video of this here. You can fix it on the fly by changing video modes, and everything returns the normal. After thinking about this I wondered whether heat build up could be a contributing factor, so I openned up my case and ripped out the PCI card right next to the AGP slot (leaving it open to the outside) and turned the case fans up a bit. This improved the air flow around the card and as far as I can tell the problem hasn't re-occured since then. So the price you pay for "noiseless" operation is that you need to be air flow aware. Make sure it gets plenty of cool air or it'll flake out.

One of the must have features for me was the TV out. I specifically wanted a TV that supported composite video for the short term, which my TV is limited to, but also supported component video. So that when I upgrade our TV to a component system I don't need to get a new video card. The ExpertVision 6200 supports all 3 video formats; Composite, S-Video and Component video via a breakout cable that plugs into the card between the DVI connector and the VGA dsub connector. The breakout cable however has seating issues and it's quite hard to get it to connect pins in the cable to the sockets in the card securely. I often have to fiddle with it to get my TV out to work after moving the PC. It's just a build quality issue, but it's annoying enough to mention. So far I can only test the composite output, and it's quality is only fair. Everytime I use it I need to adjust the brightness and contrast on the TV to suit. The picture isn't quite as clear as my old G400, but because the video processor is so much more capable the frame rate is far steadier. I think the G400 struggled to scale some video for output due to lack of processing power. The EV6200 however scales the video fine, however to my eye the output is a little less sharp and the colours a little more washed out. A marginal differece but present none the less. By default the TV out acts as a 2nd monitor in XP. Which is fine if thats what you want, but most people want the overlay window used by media players to map to the TV when active. By default the nVidia drivers don't do this. However there is a somewhat obscure option that lets you set this up. It took me a long time to figure this option out, in fact my friend ended up showing it to me.

All in all it's an alright card.
(1) Comment | Add Comment

Mac Port
Date: 5/1/2006
So with the time off over Christmas / New Year I got down to some hard core Mac porting work. I've taken the null port I finished in December and started implementing things. One night I spent 2+ hours reading the documentation just trying to decide what types to use for things like Threads, Windows/Views, Fonts, Menuitems etc. This morning I got the test app to start, detect system fonts, create the fonts, open a window, with the right position and title bar, and then go into the event loop, then shutdown cleanly. Nice!

Next on the list is implementing the in memory bitmap object, so that the image loader doesn't bitch and moan during startup when trying to create the toolbar. Then I'll try and get the drawing model and controls hooked up so that something appears in the window. I might get to a point in the next week or so where I can actually take a screenshot of the progress.
(3) Comments | Add Comment

New App: Roll Credits
Date: 20/12/2005
I havn't released a new application in a while, so presenting Roll Credits! This little app converts a still image into a scrolling credit style AVI. All the video editors that I have access to can't do this (yeah I know.. what the!) so I wrote a little itty bitty app to do it.

Video editors always want to rescale the image to fit the frame... and in my case the image was a 720x5600 pixel image created in Illustrator, and scaling to the PAL frame size caused either great bogs of black padding or stretched text. The nice thing about Roll Credits is that you get 1:1 pixels, no scaling EVER. So you can do you your pre-processing in a decent graphics application (e.g. Photoshop/Illustrator) and get that exact output in the video.

I wrote this over the weekend for a theatre production I was involved in and it worked great. The AVI output was converted and burnt to DVD and then played at the end of the production and everyone loved it.
(0) Comments | Add Comment