[FFmpeg-devel] [PATCH] Check malloc values in swscale.

[Reimar Döffinger]

On Sat, Aug 15, 2009 at 12:03:32PM -0300, Ramiro Polla wrote:
> Good idea. Patch attached.

I assume that is only the first step and you'll add checks for the
sws_allocVec return value later?

> +SwsVector *sws_allocVec(int length)
> +{
> +    SwsVector *vec = av_malloc(sizeof(SwsVector));
> +    double *coeff  = av_malloc(sizeof(double) * length);
> +    if (!coeff | !vec) {
> +        av_free(coeff);
> +        av_free(vec);
> +        return NULL;
> +    }
> +    vec->length = length;
> +    vec->coeff  = coeff;
> +    return vec;
> +}

I think it would be nicer like this (goto would probably be a bit overkill):

SwsVector *vec = av_malloc(sizeof(*vec));
if (!vec) return NULL;
vec->length = length;
vec->coeff  = av_malloc(length * sizeof(*vec->coeff));
if (!vec->coeff)
    av_freep(&vec);
return vec;

And there is more to do here anyway:

>  SwsVector *sws_getConstVec(double c, int length){
>      int i;
> -    double *coeff= av_malloc(length*sizeof(double));
> -    SwsVector *vec= av_malloc(sizeof(SwsVector));
> -
> -    vec->coeff= coeff;
> -    vec->length= length;
> +    SwsVector *vec= sws_allocVec(length);
>  
>      for (i=0; i<length; i++)
> -        coeff[i]= c;
> +        vec->coeff[i]= c;

Possible optimization: use memset if c == 0

>  static SwsVector *sws_getConvVec(SwsVector *a, SwsVector *b){
>  static SwsVector *sws_sumVec(SwsVector *a, SwsVector *b){
>  static SwsVector *sws_diffVec(SwsVector *a, SwsVector *b){
>  static SwsVector *sws_getShiftedVec(SwsVector *a, int shift){

Should all use
sws_getConstVec(0, length);
instead of reinventing it.

> -    for (i=0; i<a->length; i++) coeff[i]= a->coeff[i];
> +    for (i=0; i<a->length; i++) vec->coeff[i]= a->coeff[i];

memcpy.