// Prepare input frame
int out_size;
AVFrame frame = { .nb_samples = pv->samples_per_frame, };
AVFrame frame = { .nb_samples = pv->samples_per_frame,
.format = pv->context->sample_fmt,
.channels = pv->context->channels
};
out_size = av_samples_get_buffer_size(NULL,
pv->context->channels,