[FFmpeg-devel] [PATCH] libvmaf: exit gracefully if the library fails.

[James Almer]

On 12/8/2017 10:35 PM, Ronald S. Bultje wrote:
> Fixes trac issue #6884 and Netflix/vmaf issue #124.
> ---
>  libavfilter/vf_libvmaf.c | 28 ++++++++++++++++++++++------
>  1 file changed, 22 insertions(+), 6 deletions(-)
> 
> diff --git a/libavfilter/vf_libvmaf.c b/libavfilter/vf_libvmaf.c
> index 7670c51..d628b95 100644
> --- a/libavfilter/vf_libvmaf.c
> +++ b/libavfilter/vf_libvmaf.c
> @@ -61,6 +61,7 @@ typedef struct LIBVMAFContext {
>      int ssim;
>      int ms_ssim;
>      char *pool;
> +    int error;
>  } LIBVMAFContext;
>  
>  #define OFFSET(x) offsetof(LIBVMAFContext, x)
> @@ -158,17 +159,24 @@ static void compute_vmaf_score(LIBVMAFContext *s)
>  
>      format = (char *) s->desc->name;
>  
> -    s->vmaf_score = compute_vmaf(format, s->width, s->height, read_frame, s,
> -                                 s->model_path, s->log_path, s->log_fmt, 0, 0,
> -                                 s->enable_transform, s->phone_model, s->psnr,
> -                                 s->ssim, s->ms_ssim, s->pool);
> +    s->error = compute_vmaf(&s->vmaf_score, format, s->width, s->height,

This is an awful API break. It broke compilation for everyone using the
latest stable release of libvmaf. See ticket #6921.
How hard was for them to add a new function instead?
compute_vmaf_score() or whatever. You can't just go and change a public
function signature like this...

This can still implement this properly before a new release is tagged,
for that matter. Could you suggest that to them?

> +                            read_frame, s, s->model_path, s->log_path,
> +                            s->log_fmt, 0, 0, s->enable_transform,
> +                            s->phone_model, s->psnr, s->ssim,
> +                            s->ms_ssim, s->pool);
>  }
>  
>  static void *call_vmaf(void *ctx)
>  {
>      LIBVMAFContext *s = (LIBVMAFContext *) ctx;
>      compute_vmaf_score(s);
> -    av_log(ctx, AV_LOG_INFO, "VMAF score: %f\n",s->vmaf_score);
> +    if (!s->error) {
> +        av_log(ctx, AV_LOG_INFO, "VMAF score: %f\n",s->vmaf_score);
> +    } else {
> +        pthread_mutex_lock(&s->lock);
> +        pthread_cond_signal(&s->cond);
> +        pthread_mutex_unlock(&s->lock);
> +    }
>      pthread_exit(NULL);
>  }
>  
> @@ -187,10 +195,17 @@ static int do_vmaf(FFFrameSync *fs)
>  
>      pthread_mutex_lock(&s->lock);
>  
> -    while (s->frame_set != 0) {
> +    while (s->frame_set && !s->error) {
>          pthread_cond_wait(&s->cond, &s->lock);
>      }
>  
> +    if (s->error) {
> +        av_log(ctx, AV_LOG_ERROR,
> +               "libvmaf encountered an error, check log for details\n");
> +        pthread_mutex_unlock(&s->lock);
> +        return AVERROR(EINVAL);
> +    }
> +
>      av_frame_ref(s->gref, ref);
>      av_frame_ref(s->gmain, main);
>  
> @@ -208,6 +223,7 @@ static av_cold int init(AVFilterContext *ctx)
>  
>      s->gref = av_frame_alloc();
>      s->gmain = av_frame_alloc();
> +    s->error = 0;
>  
>      pthread_mutex_init(&s->lock, NULL);
>      pthread_cond_init (&s->cond, NULL);
>