int ff_alloc_entries(AVCodecContext *avctx, int count)
{
    int i;

    if (avctx->active_thread_type & FF_THREAD_SLICE)  {
        SliceThreadContext *p = avctx->internal->thread_ctx;
        p->thread_count  = avctx->thread_count;
        p->entries       = av_mallocz_array(count, sizeof(int));

        if (!p->entries) {
            return AVERROR(ENOMEM);
        }

        p->entries_count  = count;
        p->progress_mutex = av_malloc_array(p->thread_count, sizeof(pthread_mutex_t));
        p->progress_cond  = av_malloc_array(p->thread_count, sizeof(pthread_cond_t));

        for (i = 0; i < p->thread_count; i++) {
            pthread_mutex_init(&p->progress_mutex[i], NULL);
            pthread_cond_init(&p->progress_cond[i], NULL);
        }
    }

    return 0;
}