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August 13 Information
Hi, I've been wanting to write a program that would perform certain effects on a video, then output a modified copy. While I think I have sound ideas and am comfortable with programming, I do not know enough about video file formats and how they are played to get started and was hoping to get pointed towards some information regarding that. For example, any info on the following would help. 1.) Given a(n) wmv, mpeg, avi, etc. how would I extract an array of frames from it? 2.) If I play an a x b resolution video on a, say, 1080p screen, how does the player decide what values the extra pixels should have? 3.) More importantly, if I extracted an array of frames from an a x b res video, then added to them and increased the size to c x d res and built a video from that, would the end result be a c x d res video? For the 1st question I just need to know how frames are stored, I can figure the rest out. The 3rd sounds kind of obvious, but differences between screen resoultion and video resolution and lack of knowledge make me want to ask just to be safe. Thank you for any and all help :-) 209.252.235.206 ( talk) 06:38, 13 August 2011 (UTC)
- 1) How the frames are stored is quite complex, due to various compression methods. For example, there are compression methods for each frame, but there are others for multiple frames (if an object doesn't move, there's no need to describe it in each subsequent frame). What I've done is used software that allows me to grab single frames and extract them as as PPM RAW ASCII format, which is human readable and uncompressed RGB values (each 0-255, typically). This makes the files huge, but it does make them easy to process with a program. I've then modified the frames and stitched them together as animated GIFs, but I imagine you can make other formats, too.
- 2) See video upscaling.
- 3) Yes, you can store the frames at a higher resolution, although I suspect that all frames in a single movie must have the same resolution. Also, there are limits on the max resolution for each format.
- Something else I should add is that video rendering/processing is very slow. If you expect to, say, invert the colors on a full-length movie, I'd expect this to take many days to process, especially if you exceed the RAM of your machine and must go to paging space. StuRat ( talk) 07:38, 13 August 2011 (UTC)
- Here's a recent question we had on this desk where the format of a frame in PPM RAW ASCII format is described: [1]. StuRat ( talk) 07:56, 13 August 2011 (UTC)
- I'd consider using FFmpeg's libraries to handle the video format part, and working with the RGB frames it can provide. See eg http://dranger.com/ffmpeg/tutorial01.html Unilynx ( talk) 09:53, 13 August 2011 (UTC)
I am writing a vba code in MS Access 2007 that creates and opens a new instance of MS Excel 2007 (have added the reference to MS Excel 12.0 already). Code for reference here:
Dim xlApp as excel.application Set xlapp = CreateObject("Excel.Application")
The problem here is that every time the code runs, it opens excel 2003 instead of excel 2007. I want it to open an instance of excel 2007 instead of exce l 2003.
Additional details: OS: Win 7 I have both MS Office 2003 and 2007 installed on my system. I have already tried 'Diagnose' in MS Excel (similar to detect & repair in MS Excel 2003 which makes it default for all excel files). Also, tried un-registering excel 2007 and then registering again but didn't help. — Preceding unsigned comment added by 122.173.224.151 ( talk) 12:09, 13 August 2011 (UTC)
- You might take a look at this article, especially the section on "automation" and multiple versions. It doesn't seem to be up to date for Excel 2007, but it does give some hints to look at (figuring out what the Excel 2007 class name is). -- Mr.98 ( talk) 18:44, 13 August 2011 (UTC)
Whenever i open an excel file on my system, it opens in a new instance of excel 2007. I want them to open in same instance of excel, how can i do t? Details: OS: Win 7 MS Office 2007 — Preceding unsigned comment added by 122.173.224.151 ( talk) 12:12, 13 August 2011 (UTC)
- On Excel 2003, you untick the box Show... Windows in Taskbar, under Tools.. Options.. View. I'd guess it's the same in 2007. --
Phil Holmes (
talk) 15:57, 13 August 2011 (UTC)
- That doesn't make any difference in my Excel 2000. When I open from within the running instance, the new file opens in that instance, but if I open by double-clicking the file, the operating system (Vista) opens a new instance of Excel. Behaviour might be different in newer versions. Dbfirs 16:15, 13 August 2011 (UTC)
does anyone have passwords to databses. i mean im doing reserhc project in schol and im not finding anything in the schol databses
so i hope someone can give me passwords thanks. i'd be nice to get a pasword for teh Harvard databses thanks all — Preceding unsigned comment added by 64.183.70.187 ( talk) 15:21, 13 August 2011 (UTC)
- You appear not to understand the purpose of a password. Suggest you read the article.-- Shantavira| feed me 16:19, 13 August 2011 (UTC)
- Just FYI, to get access to the Harvard e-resources would require having a Harvard PIN, which would mean you would have access to all sorts of other Harvard student or employee services, information, etc., of whomever's PIN it was. Nobody is likely to post their PINs willingly. -- Mr.98 ( talk) 18:41, 13 August 2011 (UTC)
If a website lacks current information and valuable data, then should it be called backdated website or obsolete website? thanks-- 180.234.82.244 ( talk) 16:24, 13 August 2011 (UTC)
- "Out of date" would be the phrase I'd use. But of the choices you present, "obsolete" makes more sense than "backdated". 82.43.90.27 ( talk) 17:49, 13 August 2011 (UTC)
- See Out-of-Date Websites Invite Problems | Branding and Marketing.
- — Wavelength ( talk) 18:05, 13 August 2011 (UTC)
My iphone has been lost, and it could be anywhere in the city I'm currently residing in. I haven't downloaded MobileMe, iHound, or any of those things. Is there a way to locate it after it's already been lost? 70.179.55.4 ( talk) 22:22, 13 August 2011 (UTC)
- Call the number and see if a good Samaritan answers and agrees to return it (offer a reward just in case). However, you might not be able to hear if anybody answers over that annoying ringing coming from under your couch. :-) StuRat ( talk) 23:22, 13 August 2011 (UTC)
- After you try this, if you don't get your phone back, block it using it's IMEI. Quest09 ( talk) 13:07, 14 August 2011 (UTC)
So I am in the midst of installing Windows 7 using Parallels Desktop for Mac. I was curious as to whether because my computer is a mac, I do not have to worry about viruses, or whether even though it's a mac, because I will be running Windows on the parallels desktop, I am susceptible like an actual PC owner.-- 108.46.97.251 ( talk) 23:26, 13 August 2011 (UTC)
- It's the OS that's susceptible, not the hardware (by and large). Your Windows installation will be at risk the same as any other. ¦
Reisio (
talk) 16:58, 14 August 2011 (UTC)
- Thanks much, That's what I wanted to know. At least with this my whole computer won't die and I can just dump it and reinstall. God am I happy I got a mac.-- 108.46.97.251 ( talk) 00:22, 17 August 2011 (UTC)
| Computing desk | ||
|---|---|---|
| < August 12 | << Jul | August | Sep >> | August 14 > |
| Welcome to the Wikipedia Computing Reference Desk Archives |
|---|
| The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages. |
August 13 Information
Hi, I've been wanting to write a program that would perform certain effects on a video, then output a modified copy. While I think I have sound ideas and am comfortable with programming, I do not know enough about video file formats and how they are played to get started and was hoping to get pointed towards some information regarding that. For example, any info on the following would help. 1.) Given a(n) wmv, mpeg, avi, etc. how would I extract an array of frames from it? 2.) If I play an a x b resolution video on a, say, 1080p screen, how does the player decide what values the extra pixels should have? 3.) More importantly, if I extracted an array of frames from an a x b res video, then added to them and increased the size to c x d res and built a video from that, would the end result be a c x d res video? For the 1st question I just need to know how frames are stored, I can figure the rest out. The 3rd sounds kind of obvious, but differences between screen resoultion and video resolution and lack of knowledge make me want to ask just to be safe. Thank you for any and all help :-) 209.252.235.206 ( talk) 06:38, 13 August 2011 (UTC)
- 1) How the frames are stored is quite complex, due to various compression methods. For example, there are compression methods for each frame, but there are others for multiple frames (if an object doesn't move, there's no need to describe it in each subsequent frame). What I've done is used software that allows me to grab single frames and extract them as as PPM RAW ASCII format, which is human readable and uncompressed RGB values (each 0-255, typically). This makes the files huge, but it does make them easy to process with a program. I've then modified the frames and stitched them together as animated GIFs, but I imagine you can make other formats, too.
- 2) See video upscaling.
- 3) Yes, you can store the frames at a higher resolution, although I suspect that all frames in a single movie must have the same resolution. Also, there are limits on the max resolution for each format.
- Something else I should add is that video rendering/processing is very slow. If you expect to, say, invert the colors on a full-length movie, I'd expect this to take many days to process, especially if you exceed the RAM of your machine and must go to paging space. StuRat ( talk) 07:38, 13 August 2011 (UTC)
- Here's a recent question we had on this desk where the format of a frame in PPM RAW ASCII format is described: [1]. StuRat ( talk) 07:56, 13 August 2011 (UTC)
- I'd consider using FFmpeg's libraries to handle the video format part, and working with the RGB frames it can provide. See eg http://dranger.com/ffmpeg/tutorial01.html Unilynx ( talk) 09:53, 13 August 2011 (UTC)
I am writing a vba code in MS Access 2007 that creates and opens a new instance of MS Excel 2007 (have added the reference to MS Excel 12.0 already). Code for reference here:
Dim xlApp as excel.application Set xlapp = CreateObject("Excel.Application")
The problem here is that every time the code runs, it opens excel 2003 instead of excel 2007. I want it to open an instance of excel 2007 instead of exce l 2003.
Additional details: OS: Win 7 I have both MS Office 2003 and 2007 installed on my system. I have already tried 'Diagnose' in MS Excel (similar to detect & repair in MS Excel 2003 which makes it default for all excel files). Also, tried un-registering excel 2007 and then registering again but didn't help. — Preceding unsigned comment added by 122.173.224.151 ( talk) 12:09, 13 August 2011 (UTC)
- You might take a look at this article, especially the section on "automation" and multiple versions. It doesn't seem to be up to date for Excel 2007, but it does give some hints to look at (figuring out what the Excel 2007 class name is). -- Mr.98 ( talk) 18:44, 13 August 2011 (UTC)
Whenever i open an excel file on my system, it opens in a new instance of excel 2007. I want them to open in same instance of excel, how can i do t? Details: OS: Win 7 MS Office 2007 — Preceding unsigned comment added by 122.173.224.151 ( talk) 12:12, 13 August 2011 (UTC)
- On Excel 2003, you untick the box Show... Windows in Taskbar, under Tools.. Options.. View. I'd guess it's the same in 2007. --
Phil Holmes (
talk) 15:57, 13 August 2011 (UTC)
- That doesn't make any difference in my Excel 2000. When I open from within the running instance, the new file opens in that instance, but if I open by double-clicking the file, the operating system (Vista) opens a new instance of Excel. Behaviour might be different in newer versions. Dbfirs 16:15, 13 August 2011 (UTC)
does anyone have passwords to databses. i mean im doing reserhc project in schol and im not finding anything in the schol databses
so i hope someone can give me passwords thanks. i'd be nice to get a pasword for teh Harvard databses thanks all — Preceding unsigned comment added by 64.183.70.187 ( talk) 15:21, 13 August 2011 (UTC)
- You appear not to understand the purpose of a password. Suggest you read the article.-- Shantavira| feed me 16:19, 13 August 2011 (UTC)
- Just FYI, to get access to the Harvard e-resources would require having a Harvard PIN, which would mean you would have access to all sorts of other Harvard student or employee services, information, etc., of whomever's PIN it was. Nobody is likely to post their PINs willingly. -- Mr.98 ( talk) 18:41, 13 August 2011 (UTC)
If a website lacks current information and valuable data, then should it be called backdated website or obsolete website? thanks-- 180.234.82.244 ( talk) 16:24, 13 August 2011 (UTC)
- "Out of date" would be the phrase I'd use. But of the choices you present, "obsolete" makes more sense than "backdated". 82.43.90.27 ( talk) 17:49, 13 August 2011 (UTC)
- See Out-of-Date Websites Invite Problems | Branding and Marketing.
- — Wavelength ( talk) 18:05, 13 August 2011 (UTC)
My iphone has been lost, and it could be anywhere in the city I'm currently residing in. I haven't downloaded MobileMe, iHound, or any of those things. Is there a way to locate it after it's already been lost? 70.179.55.4 ( talk) 22:22, 13 August 2011 (UTC)
- Call the number and see if a good Samaritan answers and agrees to return it (offer a reward just in case). However, you might not be able to hear if anybody answers over that annoying ringing coming from under your couch. :-) StuRat ( talk) 23:22, 13 August 2011 (UTC)
- After you try this, if you don't get your phone back, block it using it's IMEI. Quest09 ( talk) 13:07, 14 August 2011 (UTC)
So I am in the midst of installing Windows 7 using Parallels Desktop for Mac. I was curious as to whether because my computer is a mac, I do not have to worry about viruses, or whether even though it's a mac, because I will be running Windows on the parallels desktop, I am susceptible like an actual PC owner.-- 108.46.97.251 ( talk) 23:26, 13 August 2011 (UTC)
- It's the OS that's susceptible, not the hardware (by and large). Your Windows installation will be at risk the same as any other. ¦
Reisio (
talk) 16:58, 14 August 2011 (UTC)
- Thanks much, That's what I wanted to know. At least with this my whole computer won't die and I can just dump it and reinstall. God am I happy I got a mac.-- 108.46.97.251 ( talk) 00:22, 17 August 2011 (UTC)