I am not very familiar with old opencv codes. I have an IplImage struct:
IplImage *X;
This struct filled up with data that program reads from a device. I want to show it as image in my gui program. But I am not sure which properties I need to use.
EDIT:
Values of IplImage structs all properties with same order in docs(https://docs.opencv.org/3.4/d6/d5b/structIplImage.html):
4
0
0x557684eba3b4
0x557684eba3a4
GRAY
GRAYGRAY
0
16
192
0
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0
49152
0
1
144
0
0
0
127
256
I want to get my internet interface list in C++ in linux because my program need to down Or up the link but i dont know how get the interface to modifi it.
The system call you are looking for is getifaddrs. There is a brief example program on the man page.
Within the ifaddrs there is a bit flag field ifa_flags with which you can test whether the interface is up or down.
Read from /proc/net/dev
Full description in man proc:
/proc/net/dev
The dev pseudo-file contains network device status information. This gives the number of received and sent packets,
the number of errors and collisions and other basic statistics. These are used by the ifconfig(8) program to report
device status. The format is:
Inter-| Receive | Transmit
face |bytes packets errs drop fifo frame compressed multicast|bytes packets errs drop fifo colls carrier compressed
lo: 2776770 11307 0 0 0 0 0 0 2776770 11307 0 0 0 0 0 0
eth0: 1215645 2751 0 0 0 0 0 0 1782404 4324 0 0 0 427 0 0
ppp0: 1622270 5552 1 0 0 0 0 0 354130 5669 0 0 0 0 0 0
tap0: 7714 81 0 0 0 0 0 0 7714 81 0 0 0 0 0 0
This is a text file, each interface is a line... should be easy.
For example (no error checking... just printing the interface names)
#include <fstream>
#include <iostream>
int main() {
std::ifstream in("/proc/net/dev");
int c=0;
std::string line;
for(; std::getline( in, line ); c++)
{
if(c<2) continue; // skip header
std::size_t start=line.find_first_not_of(" "); // skip leading spaces
std::size_t end=line.find_first_of(":",start); // look for the ":"
std::cout << line.substr(start,end-start) << std::endl;
}
}
I'm trying to write a baseline JPEG encoder. I already know how the handle the JFIF format (very good article, BTW). Right now I'm trying to compress a 8x8 grayscale image that is basically white. So, considering that a white pixel is basically 255, once you apply the JPEG algorithm (obviating the zig zag step, because for this example it is basically unnecessary) you get this matrix:
B = [63 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0]
As we can see, there's only one DC component (63) and no AC components. If you check the Huffman tables you find that the category is 6 (1110) and because 63 in binary is 111111 the sequence of bits for this DC component is 1110111111 (10 bits). Now, according to the algorithm, when all AC components are 0 you need to send EOB, whose sequence is 1010 (four bits). So, in the end, the final sequence of bits is 11101111111010 (14 bits).
Now, we already know that I can only write (or append) bytes to a file. So I am trying to write something like this to a new .jpeg file:
0xFF 0xD8 .. JFIF metadata ... 11101111111010 0xFF 0xD9
SOI marker block EOI marker
The question is, what should I do about those 14 bits? I guess I need to insert 2 filler bits (I don't know if there's a better term for them) to get 2 bytes but I don't know where to insert them, let alone their values (00? 01? 10? 11?). I suppose that this is a common problem in data encoding and/or low-level programming so I it is widely solved :)
The JPEG format says that:
The only padding that occurs is at the end of the scan when the remaining bits in the last byte to be filled with 1’s if the byte is incomplete.
So you are supposed to fill with 1-s here. That means in fine you should have:
1110 111111 1010 11
DC code DC value (=63) EOB (=10) Extra 1-s
In other words 11101111 11101011 which gives the 0xEF 0xEB sequence in hexadecimal.
Pro-tip: you can refer to this code section from jpec - a tiny JPEG encoder written in C. Also, the jpec_huff_write_bits includes a relevant documentation that may help you understand how to write the bits at Huffman time.
I am trying to encode a Mat CV_32FC1 image to send it over the internet with base64, the process works but the OpenCV encodes in the wrong format. Example:
vector<unsigned char> buffer;
vector<int> compression_params;
compression_params.push_back(CV_IMWRITE_PXM_BINARY);
compression_params.push_back(0);
cv::imencode(".pgm", desc, buffer, compression_params);
printf("%s", &buffer[0]);
This generates the following output:
P2
64 15
255
0 0 0 0 1 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0
etc..
According to the compression parameter and the first parameter (P2) it shouldn't be encoded as a binary format, it should be ASCII. (Source)
In itself this isn't a problem, but when I change compression_params.push_back(0) to compression_params.push_back(1) I get this output (without image data):
P5
64 15
255
I am using OpenCV 2.4.4 on iOS, how can I fix this or alternatively how can I send a Mat the good way without losing data?
Don't know if you have resolved your problem but I figured out the problem and it might apply to your case too even though you are using the iOS version, which I am not familiar with:
How do I capture images in OpenCV and saving in pgm format?
Hello Stack Overflow world :3 My name is Chris, I have a slight issue.. So I am going to present the issue in this format..
Part 1
I will present the materials & code snippets I am currently working with that IS working..
Part 2
I will explain in my best ability my desired new way of achieving my goal.
Part 3
So you guys think I am not having you do all the work, I will go ahead and present my attempts at said goal, as well as possibly ways research has dug up that I did not fully understand.
Part 1
mobDB.csv Example:
ID Sprite kName iName LV HP SP EXP JEXP Range1 ATK1 ATK2 DEF MDEF STR AGI VIT INT DEX LUK Range2 Range3 Scale Race Element Mode Speed aDelay aMotion dMotion MEXP ExpPer MVP1id MVP1per MVP2id MVP2per MVP3id MVP3per Drop1id Drop1per Drop2id Drop2per Drop3id Drop3per Drop4id Drop4per Drop5id Drop5per Drop6id Drop6per Drop7id Drop7per Drop8id Drop8per Drop9id Drop9per DropCardid DropCardper
1001 SCORPION Scorpion Scorpion 24 1109 0 287 176 1 80 135 30 0 1 24 24 5 52 5 10 12 0 4 23 12693 200 1564 864 576 0 0 0 0 0 0 0 0 990 70 904 5500 757 57 943 210 7041 100 508 200 625 20 0 0 0 0 4068 1
1002 PORING Poring Poring 1 50 0 2 1 1 7 10 0 5 1 1 1 0 6 30 10 12 1 3 21 131 400 1872 672 480 0 0 0 0 0 0 0 0 909 7000 1202 100 938 400 512 1000 713 1500 512 150 619 20 0 0 0 0 4001 1
1004 HORNET Hornet Hornet 8 169 0 19 15 1 22 27 5 5 6 20 8 10 17 5 10 12 0 4 24 4489 150 1292 792 216 0 0 0 0 0 0 0 0 992 80 939 9000 909 3500 1208 15 511 350 518 150 0 0 0 0 0 0 4019 1
1005 FARMILIAR Familiar Familiar 8 155 0 28 15 1 20 28 0 0 1 12 8 5 28 0 10 12 0 2 27 14469 150 1276 576 384 0 0 0 0 0 0 0 0 913 5500 1105 20 2209 15 601 50 514 100 507 700 645 50 0 0 0 0 4020 1
1007 FABRE Fabre Fabre 2 63 0 3 2 1 8 11 0 0 1 2 4 0 7 5 10 12 0 4 22 385 400 1672 672 480 0 0 0 0 0 0 0 0 914 6500 949 500 1502 80 721 5 511 700 705 1000 1501 200 0 0 0 0 4002 1
1008 PUPA Pupa Pupa 2 427 0 2 4 0 1 2 0 20 1 1 1 0 1 20 10 12 0 4 22 256 1000 1001 1 1 0 0 0 0 0 0 0 0 1010 80 915 5500 938 600 2102 2 935 1000 938 600 1002 200 0 0 0 0 4003 1
1009 CONDOR Condor Condor 5 92 0 6 5 1 11 14 0 0 1 13 5 0 13 10 10 12 1 2 24 4233 150 1148 648 480 0 0 0 0 0 0 0 0 917 9000 1702 150 715 80 1750 5500 517 400 916 2000 582 600 0 0 0 0 4015 1
1010 WILOW Willow Willow 4 95 0 5 4 1 9 12 5 15 1 4 8 30 9 10 10 12 1 3 22 129 200 1672 672 432 0 0 0 0 0 0 0 0 902 9000 1019 100 907 1500 516 700 1068 3500 1067 2000 1066 1000 0 0 0 0 4010 1
1011 CHONCHON Chonchon Chonchon 4 67 0 5 4 1 10 13 10 0 1 10 4 5 12 2 10 12 0 4 24 385 200 1076 576 480 0 0 0 0 0 0 0 0 998 50 935 6500 909 1500 1205 55 601 100 742 5 1002 150 0 0 0 0 4009 1
So this is an example of the Spreadsheet I have.. This is what I wish to be using in my ideal goal. Not what I am using right now.. It was done in MS Excel 2010, using Columns A-BF and Row 1-993
Currently my format for working code, I am using manually implemented Arrays.. For example for the iName I have:
char iName[16][25] = {"Scorpion", "Poring", "Hornet", "Familiar", "null", "null", "null", "null", "null", "null", "null", "null", "null", "null", "null", "null"};
Defined in a header file (bSystem.h) now to apply, lets say their health variable? I have to have another array in the same Header with corresponding order, like so:
int HP[16] = {1109, 50, 169, 155, 95, 95, 118, 118, 142, 142, 167, 167, 193, 193, 220, 220};
The issue is, there is a large amount of data to hard code into the various file I need for Monsters, Items, Spells, Skills, ect.. On the original small scale to get certain system made it was fine.. I have been using various Voids in header files to transfer data from file to file when it's called.. But when I am dealing with 1,000+ Monsters and having to use all these variables.. Manually putting them in is kinda.. Ridiculous? Lol...
Part 2
Now my ideal system for this, is to be able to use the .CSV Files to load the data.. I have hit a decent amount of various issues in this task.. Such as, converting the data pulled from Names to a Char array, actually pulling the data from the CSV file and assigning specific sections to certain arrays... The main idea I have in mind, that I can not seem to get to is this;
I would like to be able to find a way to just read these various variables from the CSV file... So when I call upon the variables like:
cout << name << "(" << health << " health) VS. " << iName[enemy] << "(" << HP[enemy] << " health)";
where [enemy] is, it would be the ID.. the enemy encounter is in another header (lSystem.h) where it basically goes like;
case 0:
enemy = 0;
Where 0 would be the first data in the Arrays involving Monsters.. I hate that it has to be order specific.. I would want to be able to say enemy = 1002; so when the combat systems start it can just pull the variables it needs from the enemy with the ID 1002..
I always hit a few different issues, I can't get it to pull the data from the file to the program.. When I can, I can only get it to store int values to int arrays, I have issues getting it to convert the strings to char arrays.. Then the next issue I am presented with is recalling it and the actual saving part... Which is where part 3 comes in :3
Part 3
I have attempted a few different things so far and have done research on how to achieve this.. What I have came across so far is..
I can write a function to read the data from let's say mobDB, record it into arrays, then output it to a .dat? So when I need to recall variables I can do some from the .dat instead of a modifiable CSV.. I was presented with the same issues as far as reading and converting..
I can go the SQL route, but I have had a ton of issues understanding how to pull the data from the SQL? I have a PowerEdge 2003 Server box in my house which I store data on, it does have NavicatSQL Premium set up, so I guess my main 2 questions about the SQL route is, is it possible to hook right into the SQLServer and as I update the Data Base, when the client runs it would just pull the variables and data from the DB? Or would I be stuck compiling SQL files... When it is an online game, I know I will have to use something to transfer from Server to Client, which is why I am trying to set up this early in dev so I have more to build off of, I am sure I can use SQL servers for that? If anyone has a good grasp on how this works I would very much like to take the SQL route..
Attempts I have made are using like, Boost to Parse the data from the CSV instead of standard libs.. Same issues were presented.. I did read up on converting a string to a char.. But the issue lied in once I pulled the data, I couldn't convert it?..
I've also tried the ADO C++ route.. Dead end there..
All in all I have spent the last week or so on this.. I would very much like to set up the SQL server to actually update the variables... but I am open to any working ideas that presents ease of editing and implementing large amounts of data..
I appreciate any and all help.. If anyone does attempt to help get a working code for this, if it's not too much trouble to add comments to parts you feel you should explain? I don't want someone to just give me a quick fix.. I actually want to learn and understand what I am using. Thank you all very much :)
-Chris
Let's see if I understand your problem correctly: You are writing a game and currently all the stats for your game actors are hardcoded. You already have an Excel spreadsheet with this data and you just want to use this instead of the hardcoded header files, so that you can tweak the stats without waiting for a long recompilation. You are currently storing the stats in your code in a column-store fashion, i.e. one array per attribute. The CSV file stores stuff in a row-wise fashion. Correct so far?
Now my understanding of your problem becomes a little blurry. But let's try. If I understand you correctly, you want to completely remove the arrays from your code and directly access the CSV file when you need the stats for some creature? If yes, then this is already the problem. File I/O is incredibly slow, you need to keep this data in main memory. Just keep the arrays, but instead of manually assigning the values in the headers, you have a load function that reads the CSV file when you start the game and loads its contents into the array. You can keep the rest of your code unchanged.
Example:
void load (std::ifstream &csv)
{
readFirstLineAndCheckThatItIsCorrect (csv);
while (!csv.eof())
{
int id;
std::string spriteName;
csv >> id;
csv >> spriteName >> kName[id] >> iName[id] >> LV[id] >> HP[id] >> SP[id] >> ...
Sprite[id] = getSpriteForName (spriteName);
}
}
Using a database system is completely out of scope here. All you need to do is load some data into some arrays. If you want to be able to change the stats without restarting the program, add some hotkey for reloading the CSV file.
If you plan to write an online game, then you still have a long way ahead of you. Even then, SQL is a very bad idea for exchanging data between server and clients because a) it just introduces way too much overhead and b) it is an open invitation for cheaters and hackers because if clients have direct access to your database, you can no longer validate their inputs. See http://forums.somethingawful.com/showthread.php?noseen=0&pagenumber=258&threadid=2803713 for an actual example.
If you really want this to be an online game, you need to design your own communication protocol. But maybe you should read some books about that first, because it really is a complex issue. For instance, you need to hide the latency from the user by guessing on the client side what the server and the other players will most likely do next, and gracefully correct your guesses if they were wrong, all without the player noticing (Dead Reckoning).
Still, good luck on your game and I hope to play it some day. :-)
IMO, the simplest thing to do would be to first create a struct that holds all the data for a monster. Here's a reduced version because I don't feel like typing all those variables.
struct Mob
{
std::string SPRITE, kName, iName;
int ID, LV, HP, SP, EXP;
};
The loading code for your particular format is then fairly simple:
bool ParseMob(const std::string & str, Mob & m)
{
std::stringstream iss(str);
Mob tmp;
if (iss >> tmp.ID >> tmp.SPRITE >> tmp.kName >> tmp.iName
>> tmp.LV >> tmp.HP >> tmp.SP >> tmp.EXP)
{
m = tmp;
return true;
}
return false;
}
std::vector<Mob> LoadMobs()
{
std::vector<Mob> mobs;
Mob tmp;
std::ifstream fin("mobDB.csv");
for (std::string line; std::getline(fin, line); )
{
if (ParseMob(line,tmp))
mobs.emplace_back(std::move(tmp));
}
return mobs;
}