#if HAVE_PTHREADS
    if (nb_input_files > 1)
    {
        f = output_files[ost->file_index];

        if (f->finished)
            return;

        pthread_mutex_lock(&f->fifo_lock);
        while (!av_fifo_space(f->fifo)) {
            ret = av_fifo_realloc2(f->fifo, av_fifo_size(f->fifo) * 2);

            if (ret < 0) {
                print_error("av_fifo_realloc2()", ret);
                exit_program(1);
            }
        }

        av_fifo_generic_write(f->fifo, &pkt, sizeof(pkt), NULL);

        pthread_mutex_unlock(&f->fifo_lock);

        return;
    }
#else
    ret = av_interleaved_write_frame(s, pkt);
    if (ret < 0) {
        print_error("av_interleaved_write_frame()", ret);
        exit_program(1);
    }
#endif