[Speex-dev] Error Executing sampledec in VC++
Steve Russell
srussell at innernet.net
Mon Oct 17 19:54:35 PDT 2005
Mon,
Since the buffer check was mentioned, I will pass on the bulk of another post which has comments interwoven with your sample. This person admitted to not knowing Speex, but at least points out your buffer overflow possibility and maybe something else helpful.
Steve
> // Program starts here:
> cout << "Starting spxdec...\n";
> fo = fopen("samp.spx","rb");
>
> if (fo == NULL)
> cout << "Error!\n";
if its not open why continue?
> else
> cout << "Okay!\n";
>
> fs = fopen ("pcmfile", "wb");
>
> if (fs == NULL)
> cout << "Error creating file!\n";
again, why continue?
> else
> cout << "File created!\n";
>
>
> while (!(feof(fo)))
> {
> decstate = speex_decoder_init (&speex_nb_mode);
maybe the decoder init doesn't like getting called multiple times?
>
> // Set default options for decoding:
> temp = 1;
> speex_decoder_ctl(decstate, SPEEX_SET_ENH, &temp);
maybe the decoder ctl doesn't like getting called multiple times?
>
>
> // Initialize spxbits (structure SpeexBits)
> speex_bits_init (&spxbits);
maybe the bits init doesn't like getting called multiple times?
>
>
> fread (&nbBytes, sizeof(int), 1, fo);
> fread (cbits, 1, nbBytes, fo);
nbBytes could be >200 thus overflowing the buffer... all buffer sizes should
be checked before being used.
>
> cout << "1"; // just to see whether the loop iterates
>
> speex_bits_read_from (&spxbits, cbits, nbBytes);
> speex_decode (decstate, &spxbits, pcm);
>
>
> // Copy 1 frame from float pcm to short spx
> for (n=0; n<FRAME_SIZE; n++)
> spx [n] = pcm [n];
>
> fwrite (spx, sizeof(short), FRAME_SIZE, fs);
>
> }
> // end of loop
> // Entire file has been read, decoded and saved
>
> speex_decoder_destroy (decstate);
> speex_bits_destroy (&spxbits);
> fclose (fo);
> fclose (fs);
>
> cout << "Finished processing!\n";
> }
-----------
----- Original Message -----
From: Duane Storey
To: 'Mo Win' ; speex-dev at xiph.org
Sent: Monday, October 17, 2005 10:40 PM
Subject: RE: [Speex-dev] Error Executing sampledec in VC++
You should really do a check to make sure
nbBytes isn't larger than 200, otherwise you're going to read past the end of your char array.
fread (&nbBytes, sizeof(int), 1, fo);
------------------------------------------------------------------------------
From: speex-dev-bounces at xiph.org [mailto:speex-dev-bounces at xiph.org] On Behalf Of Mo Win
Sent: Monday, October 17, 2005 7:31 PM
To: speex-dev at xiph.org
Subject: Re: [Speex-dev] Error Executing sampledec in VC++
Hi Steve, thanks for the advice. I placed the appropriate functions outside the while statement but I still get this error at the while loop:
First-chance exception at 0x004010fa in SPXDEC.exe: 0xC0000005: Access violation reading location 0x0000000c.
Unhandled exception at 0x004010fa in SPXDEC.exe: 0xC0000005: Access violation reading location 0x0000000c.
It looks like the same error. I've attached the code below
Thanks,
Mon
Portion of the revised code:
decstate = speex_decoder_init (&speex_nb_mode);
// Set default options for decoding:
temp = 1;
speex_decoder_ctl(decstate, SPEEX_SET_ENH, &temp);
// Initialize spxbits (structure SpeexBits)
speex_bits_init (&spxbits);
while (!(feof(fo))) // this is where the problem starts
{
fread (&nbBytes, sizeof(int), 1, fo);
fread (cbits, 1, nbBytes, fo);
cout << "1"; // just to see whether the loop iterates
speex_bits_read_from (&spxbits, cbits, nbBytes);
speex_decode (decstate, &spxbits, pcm);
// Copy 1 frame from float pcm to short spx
for (n=0; n<FRAME_SIZE; n++)
spx [n] = pcm [n];
fwrite (spx, sizeof(short), FRAME_SIZE, fs);
}
// end of loop
// Entire file has been read, decoded and saved
speex_decoder_destroy (decstate);
speex_bits_destroy (&spxbits);
fclose (fo);
fclose (fs);
cout << "Finished processing!\n";
}
On 10/18/05, Steve Russell <srussell at innernet.net> wrote:
Mon,
Here is feedback that I got concerning the access violation, i.e. the failure of the while loop below. Does this solve the problem?
Steve
My guess is that speex_decoder_init() should be outside the while().. loop
as speex_decoder_destroy() is also outside.
----- Original Message -----
From: Mo Win
To: speex-dev at xiph.org
Sent: Monday, October 17, 2005 8:05 AM
Subject: [Speex-dev] Error Executing sampledec in VC++
hey guys, I just compiled an application similar to sampledec.c (for speex 1.1.10) and it was fine but when I executed it, the app exited without doing anything. I'm using MS VC 6.0 and this was all I got - First-chance exception in sampledec.exe : 0xC0000005: Access Violation. Has anyone encountered this / does anyone know how to deal with it? by the way, sampleenc executed perfectly...
When I removed the "while" loop in sampledec, the program executed fine (I placed printf's to check which lines were executed). I also tried running the loop only once (erasing only the while statement and retaining the code within it) and it worked fine again. Something seems to be happening during loop iteration that causes the program to terminate abnormally.. any clues? thanks very much for any tip..
In gratitude,
Mon
(Below is my code. it's almost exactly like sampleenc except I read a file stream instead of stdin)
#include "speex/speex.h"
#include <stdio.h>
#include <iostream.h>
void main ()
{
// Definitions
#define FRAME_SIZE 160
#define FIXED_POINT
// Variable Declarations
FILE *fo, *fs;
short spx [FRAME_SIZE];
float pcm [FRAME_SIZE];
char cbits [200];
int nbBytes, n, temp;
void *decstate;
SpeexBits spxbits;
// Program starts here:
cout << "Starting spxdec...\n";
fo = fopen("samp.spx","rb");
if (fo == NULL)
cout << "Error!\n";
else
cout << "Okay!\n";
fs = fopen ("pcmfile", "wb");
if (fs == NULL)
cout << "Error creating file!\n";
else
cout << "File created!\n";
while (!(feof(fo)))
{
decstate = speex_decoder_init (&speex_nb_mode);
// Set default options for decoding:
temp = 1;
speex_decoder_ctl(decstate, SPEEX_SET_ENH, &temp);
// Initialize spxbits (structure SpeexBits)
speex_bits_init (&spxbits);
fread (&nbBytes, sizeof(int), 1, fo);
fread (cbits, 1, nbBytes, fo);
cout << "1"; // just to see whether the loop iterates
speex_bits_read_from (&spxbits, cbits, nbBytes);
speex_decode (decstate, &spxbits, pcm);
// Copy 1 frame from float pcm to short spx
for (n=0; n<FRAME_SIZE; n++)
spx [n] = pcm [n];
fwrite (spx, sizeof(short), FRAME_SIZE, fs);
}
// end of loop
// Entire file has been read, decoded and saved
speex_decoder_destroy (decstate);
speex_bits_destroy (&spxbits);
fclose (fo);
fclose (fs);
cout << "Finished processing!\n";
}
----------------------------------------------------------------------------
_______________________________________________
Speex-dev mailing list
Speex-dev at xiph.org
http://lists.xiph.org/mailman/listinfo/speex-dev
------------------------------------------------------------------------------
_______________________________________________
Speex-dev mailing list
Speex-dev at xiph.org
http://lists.xiph.org/mailman/listinfo/speex-dev
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.xiph.org/pipermail/speex-dev/attachments/20051017/8932a35d/attachment-0001.html
More information about the Speex-dev
mailing list