# Unity [Solved] Problem with fread( ) usage...

This topic is 4628 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

## Recommended Posts

Since this topic seems to have shifted focus, I thought it might be more useful to post on this forum. What I'm trying to do is load a WAV file into memory so that I can play it back using DirectSound. To do this, I read in the header information for the file and then try to read in the sound data... which is where I fail. I've gone into fread( ) itself and looked at what it is doing and it seems to read only 6 bytes and then just gives up. When it requests the next segment from the hard disk, it seems to be receiving nothing. I know for a fact that the file is not at it's end, yet fread just quits. Here is the code for the loading of the sound file. It is based on the article here on Gamedev.net:
#include<stdlib.h>
#include<stdio.h>
#include<string.h>

{
FILE *fp = NULL;

fp = fopen(file_name,"r");
if (!fp) //Make sure the file was found
return NULL;

unsigned char id[4]; //four bytes to hold identifiers ('RIFF','WAVE','fmt ','data');
unsigned long size; //32 bit value to hold file size
unsigned long format_length;//Length of format header; Should be 16

fread(id, sizeof(unsigned char), 4, fp); //read in first four bytes
if (strncmp((const char *)id, "RIFF",4))
return NULL;

fread(&size, sizeof(unsigned long), 1, fp); //read in 32bit size value

fread(id, sizeof(unsigned char), 4, fp); //read in 4 byte string
if (strncmp((const char *)id,"WAVE",4))
return NULL;

fread(id, sizeof(unsigned char), 4, fp); //read in 4 bytes "fmt ";
if(strncmp((const char *)id, "fmt ",4))
return NULL;

SNDFILE *tmp = (SNDFILE *) malloc(sizeof(SNDFILE));

fread(&format_length, sizeof(unsigned long),1,fp); //Should be 16
fread(&tmp->wfrmt.wFormatTag, sizeof(short), 1, fp);//Should always be WAVE_FORMAT_PCM
fread(&tmp->wfrmt.nChannels, sizeof(short),1,fp); //1 mono, 2 stereo
fread(&tmp->wfrmt.nSamplesPerSec, sizeof(unsigned long), 1, fp); //like 44100, 22050, etc...
fread(&tmp->wfrmt.nAvgBytesPerSec, sizeof(unsigned long), 1, fp); //Average Bytes per second
fread(&tmp->wfrmt.nBlockAlign, sizeof(short), 1, fp); //nChannels * BytesPerSample
fread(&tmp->wfrmt.wBitsPerSample, sizeof(short), 1, fp); //8 bit or 16 bit file?
tmp->wfrmt.cbSize = 0;

fread(id, sizeof(unsigned char), 4, fp); //read in identifier 'data'
if(strncmp((const char *)id, "data",4))
{
free(tmp);
return NULL;
}

int bytes_read; // Used to check how many bytes fread read
fread(&tmp->size, sizeof(unsigned long), 1, fp); //how many bytes of sound data do we have
tmp->buffer = (unsigned char *) malloc (sizeof(unsigned char) * tmp->size); //set aside sound buffer space
//for(int i=0; i<(int)tmp->size; i++)
//tmp->buffer = (unsigned char) rand()%256;
//tmp->buffer=fgetc(fp);

/*!!!FAILURE ON NEXT STEP!!!*/
bytes_read = fread(tmp->buffer, sizeof(unsigned char), tmp->size, fp); //read in our whole sound data chunk
fclose(fp);

FILE *out; // Test file to see what the buffer read
out = fopen("Out.txt","w+");
fwrite(tmp->buffer,sizeof(unsigned char),tmp->size,out);
fclose(out);
return tmp;

}


And here is the definition of SNDFILE:
typedef struct{
WAVEFORMATEX wfrmt;
unsigned long size;
unsigned char *buffer;
}SNDFILE;


Thanks for reading :)

##### Share on other sites
After the first 6 bytes? so half way through:

fread(&size, sizeof(unsigned long), 1, fp); //read in 32bit size value
Also, define "quit" - does your program crash or terminate? or does fread just return and you get invalid data? or something else?

##### Share on other sites
Might not fix your problem, but you should open non-text files as "binary" to avoid OS incompatibilities (which caused me a huge amount of trouble until I figured out the cause). Open as "rb" instead of "r".

##### Share on other sites
I've added a comment at the point at which it fails. It reads all of the header information just fine. The failure takes place on the last fread (i.e. when I try to read in the data segment).

Sorry about not clarifying :P

##### Share on other sites
Quote:
 Original post by Anonymous PosterMight not fix your problem, but you should open non-text files as "binary" to avoid OS incompatibilities (which caused me a huge amount of trouble until I figured out the cause). Open as "rb" instead of "r".

If I knew who you where, I'd give you a hug (and I'd rate you up)... :P

That was indeed it the problem. :D I'd never even heard about opening up in binary mode. I guess you learn something new each day...

• 10
• 14
• 11
• 10
• 11
• ### Similar Content

• Hello fellow devs!
Once again I started working on an 2D adventure game and right now I'm doing the character-movement/animation. I'm not a big math guy and I was happy about my solution, but soon I realized that it's flawed.
My player has 5 walking-animations, mirrored for the left side: up, upright, right, downright, down. With the atan2 function I get the angle between player and destination. To get an index from 0 to 4, I divide PI by 5 and see how many times it goes into the player-destination angle.

In Pseudo-Code:
angle = atan2(destination.x - player.x, destination.y - player.y) //swapped y and x to get mirrored angle around the y axis
index = (int) (angle / (PI / 5));
PlayAnimation(index); //0 = up, 1 = up_right, 2 = right, 3 = down_right, 4 = down

Besides the fact that when angle is equal to PI it produces an index of 5, this works like a charm. Or at least I thought so at first. When I tested it, I realized that the up and down animation is playing more often than the others, which is pretty logical, since they have double the angle.

What I'm trying to achieve is something like this, but with equal angles, so that up and down has the same range as all other directions.

I can't get my head around it. Any suggestions? Is the whole approach doomed?

Thank you in advance for any input!

• Hi , I was considering this start up http://adshir.com/, for investment and i would like a little bit of feedback on what the developers community think about the technology.
So far what they have is a demo that runs in real time on a Tablet at over 60FPS, it runs locally on the  integrated GPU of the i7 . They have a 20 000 triangles  dinosaur that looks impressive,  better than anything i saw on a mobile device, with reflections and shadows looking very close to what they would look in the real world. They achieved this thanks to a  new algorithm of a rendering technique called Path tracing/Ray tracing, that  is very demanding and so far it is done mostly for static images.
From what i checked around there is no real option for real time ray tracing (60 FPS on consumer devices). There was imagination technologies that were supposed to release a chip that supports real time ray tracing, but i did not found they had a product in the market or even if the technology is finished as their last demo  i found was with a PC.  The other one is OTOY with their brigade engine that is still not released and if i understand well is more a cloud solution than in hardware solution .
Would there  be a sizable  interest in the developers community in having such a product as a plug-in for existing game engines?  How important  is Ray tracing to the  future of high end real time graphics?

• Good day,

I just wanted to share our casual game that is available for android.

Description: Fight your way from the ravenous plant monster for survival through flips. The rules are simple, drag and release your phone screen. Improve your skills and show it to your friends with the games quirky ranks. Select an array of characters using the orb you acquire throughout the game.