[FFmpeg-devel,2/2] avfilter/ebur128: fix relative threshold calculation for multiple contexts

Also disallow NULL contexts.

Fixes Coverity CID 1396273, 1396279.

Signed-off-by: Marton Balint <cus@passwd.hu>
---
 libavfilter/ebur128.c | 40 +++++++++++++++++++---------------------
 1 file changed, 19 insertions(+), 21 deletions(-)

On Wed, 25 Jan 2017, Marton Balint wrote:

> Also disallow NULL contexts.
>
> Fixes Coverity CID 1396273, 1396279.
>
> Signed-off-by: Marton Balint <cus@passwd.hu>
> ---
> libavfilter/ebur128.c | 40 +++++++++++++++++++---------------------
> 1 file changed, 19 insertions(+), 21 deletions(-)
>
> diff --git a/libavfilter/ebur128.c b/libavfilter/ebur128.c
> index 012df54..e064c59 100644
> --- a/libavfilter/ebur128.c
> +++ b/libavfilter/ebur128.c
> @@ -519,49 +519,45 @@ FF_EBUR128_ADD_FRAMES(int)
> FF_EBUR128_ADD_FRAMES(float)
> FF_EBUR128_ADD_FRAMES(double)
> 
> -static int ebur128_calc_relative_threshold(FFEBUR128State * st,
> +static void ebur128_sum_relative_threshold(FFEBUR128State * st,
>                                            size_t * above_thresh_counter,
>                                            double *relative_threshold)
> {
>     size_t i;
> -    *relative_threshold = 0.0;
> -    *above_thresh_counter = 0;
>
>     for (i = 0; i < 1000; ++i) {
>         *relative_threshold += st->d->block_energy_histogram[i] *
>             histogram_energies[i];
>         *above_thresh_counter += st->d->block_energy_histogram[i];
>     }
> +}
> 
> +static void ebur128_finalize_relative_threshold(size_t *above_thresh_counter,
> +                                                double *relative_threshold)
> +{
>     if (*above_thresh_counter != 0) {
>         *relative_threshold /= (double) *above_thresh_counter;
>         *relative_threshold *= RELATIVE_GATE_FACTOR;
>     }
> -
> -    return 0;
> }
> 
> static int ebur128_gated_loudness(FFEBUR128State ** sts, size_t size,
>                                   double *out)
> {
>     double gated_loudness = 0.0;
> -    double relative_threshold;
> -    size_t above_thresh_counter;
> +    double relative_threshold = 0.0;
> +    size_t above_thresh_counter = 0;
>     size_t i, j, start_index;
> 
> -    for (i = 0; i < size; i++) {
> -        if (sts[i]
> -            && (sts[i]->mode & FF_EBUR128_MODE_I) != FF_EBUR128_MODE_I) {
> +    for (i = 0; i < size; i++)
> +        if ((sts[i]->mode & FF_EBUR128_MODE_I) != FF_EBUR128_MODE_I)
>             return AVERROR(EINVAL);
> -        }
> -    }
> 
> -    for (i = 0; i < size; i++) {
> -        if (!sts[i])
> -            continue;
> -        ebur128_calc_relative_threshold(sts[i], &above_thresh_counter,
> +    for (i = 0; i < size; i++)
> +        ebur128_sum_relative_threshold(sts[i], &above_thresh_counter,
> +                                       &relative_threshold);
> +    ebur128_finalize_relative_threshold(&above_thresh_counter,
>                                         &relative_threshold);
> -    }
>     if (!above_thresh_counter) {
>         *out = -HUGE_VAL;
>         return 0;
> @@ -596,14 +592,16 @@ static int ebur128_gated_loudness(FFEBUR128State ** sts, size_t size,
> 
> int ff_ebur128_relative_threshold(FFEBUR128State * st, double *out)
> {
> -    double relative_threshold;
> -    size_t above_thresh_counter;
> +    double relative_threshold = 0.0;
> +    size_t above_thresh_counter = 0;
>
>     if ((st->mode & FF_EBUR128_MODE_I) != FF_EBUR128_MODE_I)
>         return AVERROR(EINVAL);
> 
> -    ebur128_calc_relative_threshold(st, &above_thresh_counter,
> -                                    &relative_threshold);
> +    ebur128_sum_relative_threshold(st, &above_thresh_counter,
> +                                   &relative_threshold);
> +    ebur128_finalize_relative_threshold(&above_thresh_counter,
> +                                        &relative_threshold);
>
>     if (!above_thresh_counter) {
>         *out = -70.0;
> -- 
> 2.10.2

Ping...

Thanks,
Marton